Method for preparing HY-zeolite-supported nickel phosphide catalyst for benzene hydroalkylation reaction, and use

Abstract

The present invention belongs to the technical field of catalysis using zeolite molecular sieves, and relates to a method for preparing an HY-zeolite-supported nickel phosphide catalyst for a benzene hydroalkylation reaction, and the use. In the method, bivalent nickel ions supported by HY zeolite are used as a precursor, sodium hypophosphite is used as a reducing agent, and the catalyst precursor is subjected to a phosphating treatment by means of a chemical plating method, so as to prepare the catalyst. The method has the advantages of a simple preparation process, mild preparation conditions, and inexpensive and easily available raw materials, and is suitable for other solid acid type zeolite carriers. Under the same reaction conditions, the HY-zeolite-supported nickel phosphide catalyst has much higher catalytic activity and selectivity for benzene hydroalkylation than an HY-zeolite-supported nickel metal catalyst. In particular, the amount of isomerization byproducts, i.e., methylcyclopentane and methylcyclopentylbenzene, generated by the HY-zeolite-supported nickel phosphide catalyst is far lower than that of an HY-zeolite-supported nickel metal catalyst, and the HY-zeolite-supported nickel phosphide catalyst can replace a zeolite-supported noble metal catalyst and a zeolite-supported noble metal / non-noble metal (multi-metal) catalyst in terms of catalytic performance.

Description

Preparation method and application of HY zeolite supported phosphorus nickel catalyst for benzene hydroalkylation reaction TECHNICAL FIELD

[0001] The present application belongs to the technical field of zeolite molecular sieve catalysis, and relates to a preparation method and application of a HY zeolite supported phosphorus nickel catalyst for a benzene hydroalkylation reaction. BACKGROUND

[0002] Cyclohexylbenzene has a wide range of uses. It can be used as a high-boiling solvent and a penetrant. Due to its unique chemical stability and excellent physical properties, cyclohexylbenzene is used as an overcharge protection agent (2% to 5% addition amount) in the electrolyte of a lithium ion battery, which can improve the safety and recycling rate of the lithium battery. In addition, cyclohexylbenzene, as an intermediate for organic synthesis, provides a competitive new route for the production of phenol and cyclohexanone. At present, the most important method for producing phenol in the world is the cumene method. However, the cumene method consumes propylene and produces acetone as a co-product. Compared with phenol, the market consumption of acetone is relatively small and is prone to surplus. The oxidation of cyclohexylbenzene to obtain phenol solves this problem. This is because the co-product cyclohexanone of the cyclohexylbenzene oxidation method also has a wide range of uses. As is known to those skilled in the art, cyclohexanone is a raw material for the synthesis of caprolactam and the manufacture of nylon-6.

[0003] At present, the methods for preparing cyclohexylbenzene that have been proposed mainly include the hydrogenation of biphenyl, the alkylation of benzene with cyclohexene, and the hydroalkylation of benzene. Among them, the hydroalkylation of benzene has the greatest appeal because of its low raw material price, wide source, and green chemistry advantages. However, the hydroalkylation of benzene is still in the development stage, and the use of the catalysts disclosed so far cannot meet the requirements of industrialization. The main problems of the existing catalysts include the high price of the noble metal active component, the excessive generation of methylcyclohexylbenzene with a boiling point close to that of cyclohexylbenzene, the large amount of cyclohexane, a non-selective hydrogenation by-product, and poor catalyst stability.

[0004] As a catalyst for the hydroalkylation of benzene, it needs to have both metal centers and acid centers. Among them, the metal center is used for the selective hydrogenation of benzene to generate cyclohexene, and the acid center is used for the alkylation of cyclohexene and benzene to generate cyclohexylbenzene.

[0005] The benzene hydroalkylation reaction can be carried out on a mixed catalyst. By mixed catalyst is meant a catalyst having both metal centers and acid centers. The following patents are directed to the use of mixed catalysts for the benzene hydroalkylation reaction: US6037513 (filing date 09.07.1998), US7579511 (filing date 10.10.2008), US7847128 (filing date 12.08.2008), US7910778 (filing date 11.07.2008), US8084648 (filing date 13.01.2009), US8106243 (filing date 23.02.2009), US8178728 (filing date 24.02.2009), US8329956 (filing date 01.03.2012), US8519194 (filing date 24.11.2009), US20100191017 (filing date 29.07.2010), US20110015457 (filing date 20.01.2011), US20110288341 (filing date 24.11.2011), US20120178969 (filing date 12.07.2012) and patents CN101796000A (filing date 11.07.2008), CN101687728A (filing date 12.08.2008), CN101754940A (filing date 12.08.2008), CN102015589A (filing date 23.02.2009), CN101998942A (filing date 24.02.2009), CN102177109A (filing date 07.08.2009), CN102333747A (24.11.2009) and CN103261126A (filing date 02.12.2011). The common feature of the above patents is that the catalyst comprises a zeolitic molecular sieve, an inorganic oxide and at least one hydrogenation metal. At least 50 wt.% of the hydrogenation metal is supported on the inorganic oxide, preferably at least 75 wt.% of the hydrogenation metal is supported on the inorganic oxide, most preferably substantially all of the hydrogenation metal is supported on the inorganic oxide. The zeolitic molecular sieve has a primary pore size of at least 7 Angstroms and is selected from the group consisting of Beta zeolite, X and Y zeolites, MOR (Mordenite) and MCM-22 zeolites. The MCM-22 zeolite means a MCM-22 family zeolite, including MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49, MCM-56, UZM-8 and combinations of any two or more thereof, preferably MCM-22, -49 and -56 and combinations of any two or more thereof. The inorganic oxide comprises an oxide of at least one element from Group 2, 4, 13, 14 of the Periodic Table of the Elements, such as alumina and / or titania and / or zirconia.The at least one of the hydrogenation metals is selected from palladium, ruthenium, nickel, zinc, tin and cobalt. In addition, the preparation of cyclohexylbenzene catalyst disclosed in Chinese invention patent CN 107008477A (application date 2016.01.27) also belongs to the mixed catalyst. The catalyst comprises a hydrogenation catalyst loaded with Group VIII metal and a solid acid catalyst loaded with heteropoly acid. The Group VIII metal is selected from one or more of nickel, palladium, ruthenium and cobalt, and the support of the hydrogenation catalyst loaded with Group VIII metal comprises one or more of alumina, activated carbon, silica, zinc oxide and zirconium oxide. The method for synthesizing cyclohexylbenzene by benzene hydroalkylation disclosed in Chinese invention patent CN110563534A (2018.06.06) also involves a mixed catalyst. The catalyst comprises two zeolite molecular sieves and at least one hydrogenation metal active component. The hydrogenation metal is selected from at least one of palladium, ruthenium, platinum, rhodium and iridium, preferably at least one of palladium and ruthenium, and the content is 0.01-5%. The first zeolite molecular sieve has a pore diameter of less than 0.5 nanometers and is selected from at least one of synthetic chabazite, sodalite, synthetic hydrolcite, offretite, NaA type zeolite and synthetic sodium zeolite, and is used to encapsulate the metal hydrogenation component. The second zeolite molecular sieve is selected from at least one of zeolite molecular sieves with MFI, MWW, BEA, MOR and FAU topological structure, preferably at least one of zeolites with MCM-22 group and BEA zeolite.

[0006] Loading hydrogenation metal on an acidic support is the main method for preparing catalysts for benzene hydroalkylation reactions. The acidic support of such benzene hydroalkylation catalysts is generally selected from zeolite molecular sieves.

[0007] The published literature J. Catal., 1969, 13(4): 385-396. reported the research work on benzene hydroalkylation to cyclohexylbenzene over transition metal catalysts supported on Y-type zeolite. The study investigated the effects of the acidity and the metallicity of the catalyst on the reaction. The results showed that both the acidity and the metallicity of the catalyst were necessary conditions for the reaction to occur. The authors confirmed by tracer studies that cyclohexene was an intermediate in the formation of phenylcyclohexane, and revealed a consecutive reaction mechanism in which cyclohexene migrated from the metal hydrogenation active center to the acid site and was alkylated with benzene at the acid site to produce cyclohexylcyclohexane. The benzene hydroalkylation reaction results for two representative catalysts Ni / NaY and Pd / NaY were: cyclohexylbenzene selectivity of 78.9% and 52.3%, respectively, and benzene conversion of 12.6% and 42.0%, respectively. The above results showed that the conversion of benzene for the benzene hydroalkylation reaction mainly depended on the metal hydrogenation activity of the catalyst.

[0008] Appl. Catal. A-Gen., 2001, 211(2): 259-268 reports a four-component catalyst Ni / Pt / RE-13X prepared by impregnating Pt on 13X zeolite containing Ni and rare earths and its catalytic performance for the hydroalkylation of benzene. 13X (NaX) and NaY zeolites belong to the faujasite structure and have a large pore size (12-membered ring aperture, ca. 0.7 nm pore size). The authors loaded 5% Ni, 0.1% Pt and 2.5% rare earth elements on 13X zeolite, respectively. The obtained catalysts were used to catalyze the hydroalkylation of benzene at a liquid hourly space velocity of 16.56 h -1 , a benzene to hydrogen molar ratio of 1:1, a reaction temperature of 170°C and a reaction pressure of 3.5 MPa, obtaining a benzene conversion of between 10% and 20% and a cyclohexylbenzene selectivity of about 75%. The design idea of the four-component catalyst is to use the hydrogen spillover effect of the noble metal Pt to promote the reduction of the non-noble transition metal Ni and to use the induced electron transfer of the rare earth elements to change the adsorption strength of benzene or intermediate products on the metal, thus favoring the formation of cyclohexylbenzene.

[0009] The pore size of the zeolite molecular sieve has a great influence on the selectivity of the hydroalkylation product. Compared with the previously mentioned faujasite (X, Y), the pore size of 5A zeolite is smaller, and the benzene molecules cannot enter the pores thereof. According to the research results of the published document Appl. Catal. A-Gen., 2001, 211(2): 259-268, the Ni / Pt / RE-5A zeolite catalyst has almost no activity in the benzene hydroalkylation reaction. In addition to the faujasite (X, Y), other zeolites with larger pore sizes, such as ZSM-20, β, MOR and MCM-22, etc., are suitable as the acidic carriers of the benzene hydroalkylation catalyst. However, the influence of the pore size on the reaction is not only this. For mesoporous zeolites like the MFI type zeolite (pore size is 10-membered ring, and the pore size is between 0.5-0.55 nm), because the pore size is relatively small, in the stage of loading the metal in the preparation of the catalyst, the problem that the metal precursors cannot enter the pores often occurs, resulting in the deposition of most of the metal on the outer surface of the zeolite. The zeolite carriers with larger pore sizes like the faujasite (X, Y) and the BEA type zeolite (such as β) are beneficial to the entry of the metal precursors into the pores thereof, thereby being beneficial to the more uniform dispersion of the metal components, making the metal centers and the acidic centers closer, and thus being beneficial to the preparation of the bifunctional catalyst with better synergistic catalytic performance. Because of the above reasons, in the research of the published document Stud. Surf. Sci. Catal. 2007, 170(7): 1228-1235, when the MFI type zeolite loaded with Ru / Ni is used as the hydroalkylation catalyst, only the cyclohexane is generated without detecting the hydroalkylation product. In the Ru / Ni / β catalyst reported in the published document Micropor. Mesopor. Mat., 2007, 105(1): 181-188, a large amount of cyclohexylbenzene product is generated.

[0010] The published document Chin J Catal, 2007, 28(3): 246-250 reports the research work of synthesizing cyclohexylbenzene by using the Pd / Hβ bifunctional catalyst to catalyze the benzene hydroalkylation reaction. Specifically, the Hβ zeolite with a silica-alumina ratio of 25-200 is used as the carrier to load the noble metal Pd. The reaction is carried out in an autoclave (batch reaction). In each reaction experiment, the benzene feed amount is 5 g, and the catalyst amount is 0.2 g. The reaction is carried out under the conditions of a H2 pressure of 2.5 MPa and a temperature of 200°C, and the reaction time is 3 h. A set of representative results obtained by using the Pd / Hβ catalyst with a silica-alumina ratio of 25 and a Pd loading amount of 0.2% are as follows: benzene conversion rate 24.3%, cyclohexylbenzene selectivity 88.0%. The results show that the Hβ with a low silica-alumina ratio is more beneficial to the benzene hydroalkylation reaction. This is because the Hβ zeolite with a low silica-alumina ratio can provide more B acid sites, reducing the opportunity of the cyclohexene to continue to be hydrogenated into cyclohexane.

[0011] The catalytic performance of Ru, Ni catalysts supported on zeolite β and MOR for benzene hydroalkylation was reported in the open literature Micropor. Mesopor. Mat., 2007, 105(1): 181-188 and Pet. & Coal, 2008, 50(1): 44-51, respectively. Compared with MOR, the channels of zeolite β are more open, so the dispersion of metals in the channels of Ru / Ni-β catalyst is more uniform, the metal centers are closer to the acid centers, and the hydroalkylation activity of the catalyst is better. However, due to the open channel structure of zeolite β, the Ru / Ni-β catalyst generates more bulky multi-alkylated products, such as dicyclohexylbenzene.

[0012] The open literature Mod. Chem. Ind., 2013, 33(8): 73-77 reported the preparation of bifunctional catalysts with Ru supported on zeolite Hβ, ZSM, MOR and MCM-41 molecular sieve, and their catalytic performance in benzene hydroalkylation. The catalysts were prepared by the incipient wetness impregnation method, and the Ru source was ruthenium chloride solution. The reaction evaluation was also carried out in a high-pressure reactor (batch reaction). The benzene feed amount was 32 g and the catalyst amount was 1.6 g in each reaction experiment. The reaction results obtained with 0.2% Ru / Hβ bifunctional catalyst at a reaction temperature of 200°C and a hydrogen pressure of 2.5 MPa for 4 h were: benzene conversion 67.6%, cyclohexylbenzene selectivity 47.8%, and the by-products mainly cyclohexane (about 20%) and dicyclohexylbenzene (about 35%). The results showed that Hβ zeolite is a suitable catalyst carrier. The disadvantage of MOR and other zeolites is that the number of strong acid centers is small, which cannot play a good alkylation role.

[0013] The open literature Mod. Chem. Ind., 2013, 33(8): 73-77 reported the preparation of Ni / β, Pd / β, Ru / β and Pt / β catalysts on the same β zeolite carrier and their use in benzene hydroalkylation. The metal loadings of different catalysts were the same. The benzene hydroalkylation reaction was carried out in a high-pressure reactor. The reaction pressure was 2.5 MPa, the reaction temperature was 200°C, and the reaction time was 4 h. The benzene conversion of the four catalysts increased by 1.5%, 25.0%, 67.6%, and 94.5%, respectively, and the cyclohexylbenzene selectivity was 54.9%, 50.3%, 47.9%, and 1.3%, respectively. These results show the important influence of the type of supported metal on the results of benzene hydroalkylation.

[0014] The publication Petrochem. Techno., 2015, 44(2): 175-180 reports on the study of the adjustment of the performance of Ni / Hβ catalysts for the benzene hydroalkylation by introducing Pt, Pd, Ru, Ir, Re, Cu as the second metal component, respectively. The results show that the introduction of Pt, Pd, Ru, Ir, Re with good hydrogenation activity promotes the hydrogenation reaction rate of the catalyst, resulting in an increase in the selectivity of cyclohexane and a decrease in the selectivity of cyclohexylbenzene. Surprisingly, the introduction of Cu without hydrogenation activity improves the performance of the catalyst. Under the conditions of a reaction temperature of 210°C, a hydrogen pressure of 2 MPa, and a reaction time of 1 h, the benzene conversion rate of the 4% Ni-0.2% Cu / Hβ catalyst can reach 57.74%, and the selectivity of cyclohexylbenzene can reach 71.38%.

[0015] The following invention patents all involve loading transition metals, noble metals, and rare earth metal active components onto hydrogen-type zeolites to prepare multi-metal catalysts for the method of preparing cyclohexylbenzene by benzene hydroalkylation: CN105582989A (2014.10.24), CN107866266A (application date 2016.9.26), CN107866262A (application date 2016.9.26), CN107866268A (application date 2016.9.26), CN107930675A (application date 2016.10.13), CN107930679A (application date 2016.10.13), CN107930680A (application date 2016.10.13), CN107930683A (application date 2016.10.13), CN107930684A (application date 2016.10.13). In general, these invention patents disclose catalysts comprising a hydrogen-type zeolite carrier and an active component impregnated on the hydrogen-type zeolite carrier; the active component comprises noble metals and non-noble metals; the noble metals include palladium, ruthenium, iridium, and rhodium; the non-noble metals include aluminum, iron, nickel, molybdenum, zinc, copper, manganese, and rare earth elements; the hydrogen-type zeolite carrier is selected from β, MOR, or MWW type zeolites, wherein the hydrogen-type β zeolite is a binder-free shaped zeolite.

[0016] The publication Fine Chem., 2017, 34(10): 1161-1168 reported the effect of introducing rare earth elements on the physicochemical properties of the catalyst and the performance of the benzene hydroalkylation reaction on the basis of binary metal-loaded Hβ zeolite. The results showed that the introduction of La into the binary metal-loaded Hβ zeolite catalysts Ni-Pd / Hβ, Ni-Pt / Hβ, Ni-Ru / Hβ and Ni-Cu / Hβ could make the particle size of the loaded metal components smaller, the dispersion degree higher, the specific surface area of the catalyst increase, the proportion of B acid centers increase, and could promote the complete reduction of NiO to form a catalytically active phase. The reaction evaluation was carried out in a fixed bed reactor, the reaction temperature was 220℃, the GHSV H2 2500h -1 , the LHSV of benzene was 2.0h -1 Under the above conditions, the benzene conversion rate of the 4%Ni-0.2%Pd-3%La / Hβ catalyst was 34.44%, and the selectivity of cyclohexylbenzene was 74.67%.

[0017] The publication Mol. Catal., 2017, 442: 27-38. reported the benzene hydroalkylation bifunctional catalysts prepared by loading noble metal Pd on HY zeolites with different silicon to aluminum ratios and their reaction performance. The silicon to aluminum ratio of the HY zeolite was between 5 and 60. The authors of this study adjusted the catalytic synergy between the metal centers and the acid centers by adjusting the silicon to aluminum ratio of the zeolite and the loading amount of the noble metal Pd to achieve the best benzene hydroalkylation activity and the highest possible selectivity of cyclohexylbenzene. The reaction was carried out in a fixed bed reactor, and the reaction conditions were as follows: reaction temperature 150℃, reaction pressure 2.0Mpa, mass space velocity of benzene 0.5h -1 , hydrogen to benzene molar ratio 1. The results showed that the Pd(0.2wt%) / HY(silicon to aluminum ratio 5) catalyst had good benzene hydroalkylation reaction activity and selectivity, the benzene conversion rate was 42%, and the selectivity of cyclohexylbenzene was 77%.

[0018] In Chinese invention patents CN105439802 (application date 2016.06.30), CN106518601 (application date 2017.03.22), CN106518602 (application date 2017.03.22) and CN112138724A (2019.06.26), a method for preparing cyclohexylbenzene by hydroalkylation was disclosed, which mainly solved the problem of poor stability of the catalyst used in the prior art. The benzene hydroalkylation reaction conditions provided by the invention were as follows: reaction temperature 100-250℃, reaction pressure 0.5-4.0MPa, hydrogen to benzene molar ratio 0.1-2, and benzene weight space velocity 1-10h -1The catalyst is made from a silicone microporous zeolite containing 0.05 to 5 wt.% of a metal active component. The metal active component is at least one of palladium, ruthenium, platinum, rhodium, iridium, nickel, copper or cobalt. Preferably, at least one of palladium or ruthenium. The silicone microporous zeolite has a Si NMR solid state nuclear magnetic resonance spectrum containing at least one peak between -80 and +50 ppm. 29 Si NMR solid state nuclear magnetic resonance spectrum containing at least one peak between -80 and +50 ppm. 29 Si NMR solid state nuclear magnetic resonance spectrum containing at least one peak between -80 and +50 ppm. The synthesis of the silicone microporous zeolite requires the use of at least one of a halosilane, a silazane or an alkoxysilane. The metal active component is loaded by dissolving a precursor salt of the metal active component in a dilute nitric acid solution (peptizing agent) during catalyst shaping.

[0019] Chinese invention patent CN107303500A (2016.04.25) discloses a metal / H-MCM-22 catalyst. The technical feature of its preparation method is that first the ions of the metal component are complexed with an organic amine to form a complex of metal ions, and then an aluminum source, a silicon source and a template are added to form a gel and crystallize to form the metal / H-MCM-22 catalyst. In this invention, the active metal enters the molecular sieve channel during the construction of the molecular sieve framework, and the active sites are highly uniformly distributed, so when applied to benzene hydroalkylation reaction, both the conversion rate of benzene and the selectivity of cyclohexylbenzene are relatively high. The metal component includes one, two or three combinations of nickel, palladium, platinum, ruthenium, rhenium, iridium, copper, tin, lanthanum and cerium, and the preferred is two or three combinations thereof. The complexing agent is any one of piperazine, piperidine or hexamethylene imine. Chinese invention patent CN107303512B (2016.04.25) discloses a metal / β zeolite catalyst prepared by a similar method. Before synthesizing this bifunctional β zeolite, first the ions of the metal component are complexed with a sub-template for synthesizing β zeolite to form a complex of metal ions and sub-template, and then an aluminum source, a silicon source and a main template are added to form a gel and crystallize to form β zeolite. The metal active component is one or a combination of two or more of nickel, palladium, platinum, ruthenium, rhenium, iridium, copper, zinc, lanthanum or cerium, and the sub-template for Beta molecular sieve synthesis is selected from any one of diethylamine, triethylamine, diisopropylamine, tri-n-butylamine, N,N'-dimethyl ethylenediamine, N,N'-diethyl propylenediamine, N,N,N',N'-tetramethyl ethylenediamine or N,N,N',N'-tetraethyl propylenediamine. In addition, Chinese invention patent CN114130421A (2020.09.04) also discloses a benzene hydroalkylation catalyst prepared by using a metal complex. The catalyst includes inorganic oxides, zeolites and metal components. The inorganic oxides are preferably at least one selected from aluminum oxide, silicon oxide and titanium oxide. The zeolites are at least one selected from β, Y, MCM-22, PSH-3, SSZ-25, MCM-49 and MCM-56, preferably at least one selected from β, Y and MCM-22. The metal components supported on the zeolites include at least one of Ru, Pd, Pt, Ni, Co, Mo and W, preferably at least one of Pd, Ru and Ni. The metal components account for 0.01-5 wt.%, preferably 0.1-3 wt.% of the hydrogenation alkylating catalyst by weight of the metal elements.The preparation method of the catalyst is as follows: (1) mixing a salt solution containing a metal component with inorganic or / and organic ligands to form a complex solution; (2) mixing the complex solution obtained in step (1) with an alkaline solution to obtain a mixed alkaline solution; (3) adding the mixed alkaline solution obtained in step (2) to a synthesis raw material mixture of zeolite, and performing a crystallization reaction under zeolite synthesis conditions to obtain a metal-containing zeolite; (4) mixing and kneading the metal-containing zeolite obtained in step (3) with an inorganic oxide, and then drying and calcining to obtain a hydroalkylation catalyst. Overall, the metal hydrogenation component is directly encapsulated in the zeolite by in-situ synthesis, and more than 85% of the metal particles have a particle size of 2-4 nm.

[0020] Chinese invention patents CN111085251A and CN111085243A (2018.10.23) disclose a kind of metal-loaded catalyst. This kind of catalyst is an acidic material with a mesoporous alumina layer on the surface of a supported Group VIII metal with hydrogenation activity. The Group VIII metal with hydrogenation activity is selected from one or more of nickel, palladium, ruthenium, cobalt and platinum. The active metal accounts for 0.01-10 wt.% of the total mass of the catalyst, preferably 0.1-0.5 wt.%. The acidic material with a mesoporous alumina layer on the surface is an acidic material with a FAU crystal phase structure and a pseudo-boehmite structure that grows together in interconnection, with a probable pore distribution of 3-4 nm and 7-10 nm, respectively. The technical feature of the catalyst preparation method is to load the Group VIII metal with hydrogenation activity onto the acidic material with a mesoporous alumina layer on the surface by impregnation or precipitation deposition.

[0021] Chinese invention CN109772432A (2019.02.01) discloses a coated metal catalyst. The catalyst is composed of an active component, a zeolite and a framework, the active component is loaded on the zeolite, and the molecular sieve loaded with the active component is coated inside the framework. The active component is one of metal elements Ru, Rh, Pt, Pt and Ni, the zeolite is one of H-type β zeolite, H-type MOR zeolite and H-type Y zeolite, and the framework is an inorganic silica-alumina structure with the same crystal phase as the zeolite. The technical feature of the catalyst preparation method is: the first step is to load a metal precursor on the H-type zeolite by equal-volume impregnation, thereby preparing an H-type zeolite catalyst loaded with a metal element active component. The second step is to uniformly mix the H-type zeolite catalyst loaded with the metal element active component with a silica-alumina gel of a certain composition, and hydrothermally crystallize.

[0022] Chinese invention patent CN 111036283 A (2019.12.31) discloses a preparation method and application of a benzene hydroalkylation catalyst. Its technical features are that metal ruthenium is loaded on a zeolite carrier by deposition precipitation method, and then the loaded zeolite catalyst is subjected to secondary crystallization to obtain the final benzene hydroalkylation catalyst. The purpose of secondary crystallization is to make the active metal ruthenium better enter the zeolite pore channel, improve the cyclohexylbenzene selectivity, and at the same time reduce the agglomeration of active metal in the process of hydroalkylation reaction. The zeolite carrier is one of MCM-22 and beta zeolite, and the loading amount of metal ruthenium is 0.2-0.8wt.%.

[0023] Chinese invention patent CN114130424A (2020.09.04) discloses a hydroalkylation catalyst and its preparation method and application. The catalyst of the invention is loaded with metal components by modified zeolite and shaped with inorganic oxide. The basic zeolite used in the modified zeolite is selected from at least one of beta, Y, MCM-22, PSH-3, SSZ-25, MCM-49, MCM-56, preferably at least one of beta, Y, MCM-22. The metal component includes at least one of Ru, Pd, Pt, Ni, Co, Mo, W, preferably at least one of Pd, Ru, Ni. The metal component accounts for 0.01-5wt.% in element, preferably 0.1-3wt.% by weight of the hydroalkylation catalyst. At least 50wt.% of the metal is loaded on the modified zeolite by equal volume impregnation, preferably 60-100wt.% of the metal is loaded on the modified zeolite. The preparation method of the modified zeolite includes that the basic zeolite is first subjected to ammonium exchange and hydrothermal treatment, and then subjected to alkaline treatment and acid treatment in sequence. The ratio of acid center density to micropore volume (Cas / Vmicro) of the modified zeolite is 1000-2000μmol / cm 3 .

[0024] Chinese invention patent CN114130420A (2020.09.04) discloses a catalyst for benzene hydroalkylation and its preparation method and application. The catalyst in the invention comprises inorganic oxide, modified zeolite and metal component. The modified zeolite is prepared by first ammonium exchange and first hydrothermal treatment of base zeolite, and then second ammonium exchange and second hydrothermal treatment, and the mesopore to micropore volume ratio (Vmeso / Vmicro) is 0.5-2.0. The base zeolite is selected from at least one of β, Y, MCM-22, PSH-3, SSZ-25, MCM-49, MCM-56, preferably at least one of β, Y, MCM-22. The metal component comprises at least one of Ru, Pd, Pt, Ni, Co, Mo, W, preferably at least one of Pd, Ru, Ni. The metal hydrogenation component of the catalyst can be introduced in two ways: (1) all are loaded on the modified zeolite by impregnation before the catalyst is formed; (2) part is loaded on the modified zeolite and part is loaded on the inorganic oxide by impregnation before the catalyst is formed.

[0025] Chinese invention patent CN114180596A (2020.09.15) discloses a catalyst for benzene hydroalkylation. The catalyst is prepared by loading noble metal rhodium on mesoporous NaY zeolite. The mesoporous NaY zeolite is synthesized in the presence of organosilane and tetramethylammonium hydroxide, and is post-treated with alkali liquor, and the mesopore volume is greater than or equal to 0.140 cm 3 / g, and the BET specific surface area is greater than or equal to 500 m 2 / g.

[0026] Chinese invention patent CN108993577A (2018.06.13) discloses a catalyst for benzene hydrogenation to cyclohexylbenzene and its preparation method and application. The catalyst takes noble metal-non-noble metal as active component and zeolite as carrier, and its general formula can be expressed as M1M2 / zeolite, wherein M1 represents one of noble metals Ru, Rh, Pt or Pd, M2 represents one or a combination of two of non-noble metals Fe, Co, Ni or Cu, and the zeolite is one of H-MCM-22, Hβ, HY or 13X. According to mass percentage, the content of each component of the catalyst is M1 0.01%-1%, preferably 0.03%-0.08%, M2 5%-35%, preferably 12%-30%, and the balance is the carrier zeolite. The preparation method of the catalyst involves ammonia coordination-hydrazine hydrate chemical reduction method (loading non-noble metal M2 on zeolite). The catalyst is applied to the reaction of catalyzing benzene hydroalkylation to prepare cyclohexylbenzene, and has good stability.

[0027] In addition, Chinese patent CN 115920886 (2023.02.23) discloses a benzene hydroalkylation catalyst of palladium supported tungsten oxide-montmorillonite. The specific preparation method of the catalyst is as follows: first, the montmorillonite is heated and stirred in a phosphoric acid solution, centrifuged and washed, dried and then calcined; second, the activated montmorillonite is immersed in an ammonium metatungstate solution, then heated to evaporate the water, and the montmorillonite supported tungsten oxide is obtained after calcination of the acidic support; then, the acidic support is immersed in a palladium chloride solution, then heated to remove the water, dried and calcined to reduce, obtaining the palladium bifunctional catalyst supported by the acidic support.

[0028] In summary, at present, the high-activity and high-selectivity benzene hydroalkylation catalysts reported at home and abroad are mainly catalysts containing noble metals, transition metals / noble metals, transition metals / noble metals / rare earth metals. The benzene hydroalkylation catalysts involving noble metals are expensive and have high cost, which is not conducive to industrial use.

[0029] The following patents and documents are related to the research work of non-noble metal nickel catalyst for benzene hydroalkylation synthesis of cyclohexylbenzene: published documents J. Catal., 1969, 13(4): 385-396., J. Catal., 1970, 16(1): 62-68., Bull. JPN. Petrol. Inst., 1976, 18(1): 25-31., US: 4268699 (application date 1981-5-19), Mod. Chem. Ind., 2013, 33(8): 73-77., FINE CHEM., 2017, 34(10): 1161-1168., ACTA PETROL SIN: PET PROCESS SECTION, 2019, 35(6): 1067-1076., ACS Appl. Mater. Interfaces 2022, 14, 31998-32008., ACTA PETROL SIN: PET PROCESS SECTION, 2023, 39(2): 340-348.

[0030] For example, Chinese invention patent CN111250148A (2020.03.25) discloses a catalyst for the benzene hydroalkylation to cyclohexylbenzene, the technical feature of which is that the active component of the catalyst is a non-noble metal M, including at least one of Fe, Co, Ni and Cu, preferably at least one of Ni and Cu, more preferably Cu, and one of Hβ, HY and Hβ-HY composite zeolite as the carrier. The mass content of non-noble metal M is 0.1% to 40%, preferably 0.1-25%, more preferably 0.2-18%, and most preferably 0.3-17%. The technical feature of the catalyst preparation method is to first add zeolite to a non-noble metal salt solution containing a protective agent and a complexing agent, then add a precipitating agent and carry out hydrothermal reaction to prepare the precursor of the catalyst. Finally, the precursor of the catalyst is calcined to obtain the finished catalyst. The protective agent is ethylene glycol or glycerol. The complexing agent is one or more of ethylenediamine, acetylacetone and disodium ethylenediaminetetraacetate. The precipitating agent is preferably at least one of sodium hydroxide, urea, ammonium chloride, ammonia, ammonium bicarbonate, ammonium carbonate, ammonium nitrate and ammonium sulfate, more preferably at least one of sodium hydroxide, urea, ammonium chloride and ammonia, and most preferably urea.

[0031] The use of non-noble metal nickel as the metal active center to prepare a benzene hydroalkylation catalyst has a lower cost, which meets the requirements of industrial catalytic technology for catalyst cost, but the problem is that the selectivity of the product cyclohexylbenzene is not high, and the content of the by-products methylcyclopentane and methylcyclopentylbenzene is high. The boiling point of the former is close to that of cyclohexane, and the boiling point of the latter is close to that of the target product cyclohexylbenzene, which leads to difficult separation and is not conducive to industrial application.

[0032] Transition metal phosphides have special structures and have the potential to be "pseudo Pt catalysts". In transition metal phosphides, the crystal lattice of metal atoms is doped with phosphorus atoms. Therefore, compared with the metal parent, the distance between the metal atoms of the transition metal phosphide is increased, which causes the interaction force between the metal atoms to be weakened to some extent, thereby causing the d band of the metal to shrink to some extent, increasing the state density near the Fermi level. Because of this, transition metal phosphides have characteristics similar to noble metals. In many hydrogen-related reactions, transition metal phosphides exhibit excellent catalytic activity, such as dehydrogenation reactions, hydrogenation reactions (hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO), and hydrodechlorination (HDC)) and the like.

[0033] There are more than 100 known transition metal phosphides, including Fe, Co, Ni, Cu, W, Mo, V, etc. There are 8 forms of nickel phosphide, which are Ni3P, Ni5P2, Ni2P, NiP, NiP2, NiP3, NiP4 and NiP5. The most stable form is Ni3P, which is a semiconductor with a band gap of 0.7 eV. The most stable form of cobalt phosphide is CoP, which is also a semiconductor with a band gap of 0.7 eV. The most stable form of copper phosphide is Cu3P, which is a semiconductor with a band gap of 0.7 eV. The most stable form of vanadium phosphide is V3P, which is a semiconductor with a band gap of 0.7 eV. The most stable form of molybdenum phosphide is MoP, which is a semiconductor with a band gap of 0.7 eV. The most stable form of tungsten phosphide is WP, which is a semiconductor with a band gap of 0.7 eV. 12P5, Ni2P, Ni5P4, NiP, NiP2and NiP3. Different compositions of metal phosphides result in significant differences in their structures, electronic properties, magnetic properties, optical properties, and catalytic properties. Generally, metal-rich phosphides have metallic properties and can be used as catalysts for hydrogenation and hydrogenolysis reactions. The published literature J. Chem. Thermodyn., 2007, 35(4): 458-464 reports theoretical calculations of different phosphides of nickel (Ni3P, Ni2P, Ni5P4, NiP, NiP2, and NiP3) using density functional theory (DFT). According to the calculated results of the lattice energy, the thermal stability of the phosphides of nickel decreases in the order of Ni3P > Ni2P > Ni5P4 > NiP > NiP2 > NiP3. 12 P5, Ni2P, Ni5P4, NiP, NiP2and NiP3. Different compositions of metal phosphides result in significant differences in their structures, electronic properties, magnetic properties, optical properties, and catalytic properties. Generally, metal-rich phosphides have metallic properties and can be used as catalysts for hydrogenation and hydrogenolysis reactions. The published literature J. Chem. Thermodyn., 2007, 35(4): 458-464 reports theoretical calculations of different phosphides of nickel (Ni3P, Ni2P, Ni5P4, NiP, NiP2, and NiP3) using density functional theory (DFT). According to the calculated results of the lattice energy, the thermal stability of the phosphides of nickel decreases in the order of Ni3P > Ni2P > Ni5P4 > NiP > NiP2 > NiP3. 12 P5, Ni2P, Ni5P4, NiP, NiP2and NiP3. Different compositions of metal phosphides result in significant differences in their structures, electronic properties, magnetic properties, optical properties, and catalytic properties. Generally, metal-rich phosphides have metallic properties and can be used as catalysts for hydrogenation and hydrogenolysis reactions. The published literature J. Chem. Thermodyn., 2007, 35(4): 458-464 reports theoretical calculations of different phosphides of nickel (Ni3P, Ni2P, Ni5P4, NiP, NiP2, and NiP3) using density functional theory (DFT). According to the calculated results of the lattice energy, the thermal stability of the phosphides of nickel decreases in the order of Ni3P > Ni2P > Ni5P4 > NiP > NiP2 > NiP3.

[0034] The published literature J. Catal., 2012, 294: 184-198 reports the catalytic performance of a series of SiO2-supported metal phosphides in the hydrogenation-deoxygenation (HDO) of 2-methyltetrahydrofuran (2-MTHF). The results show that, under the conditions of 300 °C and 0.1 MPa, the order of hydrogenation activity of noble metal catalyst Pd and transition metal phosphides is Ni2P > WP > MoP > CoP > FeP > Pd. That is, the activity of all metal phosphides is better than that of noble metal Pd, and Ni2P has the highest activity. The above results indicate, on the one hand, the noble metal-like characteristics of transition metal phosphides, and on the other hand, the application potential of nickel phosphide catalysts. The published literature J. Catal., 2003, 216(1): 343-352 reports the catalytic activity of a variety of transition metal phosphides for the hydrodesulfurization and hydrodenitrogenation of dibenzothiophene, and the results show that the catalytic activity of different phosphides decreases in the order of Ni2P, WP, MoP, CoP to Fe2P. In the published literature Appl. Catal. A: General, 2011, 391(1-2): 305-310, the authors studied the performance of a series of supported transition metal phosphide catalysts (Ni2P / SiO2, Fe2P / SiO2, MoP / SiO2, Co2P / SiO2, and WP / SiO2) for the hydrodeoxygenation of guaiacol. The results show that, compared with other transition metal phosphide catalysts, the nickel phosphide catalyst has higher catalytic activity. In the temperature range of 200-300 °C, the order of catalytic activity of different phosphides from high to low is Ni2P > Co2P > Fe2P > WP > MoP. The main products of the reaction are benzene, phenol, and anisole.

[0035] The publication Appl. Catal. B-Environ., 2017, 219: 619-628. reported the catalytic performance differences of four different catalysts, Ni / SiO2, Ni / ZrO2, Ni2P / SiO2 and Ni2P / ZrO2 in the m-cresol HDO reaction. The results showed that under the conditions of 340℃ and 4.0Mpa H2 pressure, the HDO activity of the above four catalysts in turn was: Ni2P / ZrO2>Ni2P / SiO2>>Ni / ZrO2>Ni / SiO2. This shows that the carrier not only has an important influence on the catalytic performance of the supported metal, but also has an important influence on the catalytic performance of the metal phosphide.

[0036] It is worth noting that Ni2P as a typical representative of nickel phosphide catalysts, although it has high catalytic activity, it has poor stability and is easy to lose P, and it is easy to convert to Ni3P in contact with water during chemical reactions. Fortunately, the Ni3P catalyst not only has the characteristics of high activity, but also has the characteristics of good stability. The publication Catal. Today, 2020. reported the catalytic activity of Ni3P, Ni 12 P5, Ni2P catalysts in the catalytic phenol hydrogenation and deoxygenation (HDO) reaction. It was found that compared with the latter two, the electronic binding energy of Ni δ+ in Ni3P was lower, which had stronger metallicity, so that the conversion of phenol and the selectivity of hydrogenation product cyclohexanol of Ni3P were higher than those of the other two catalysts.

[0037] The preparation methods of nickel phosphide catalysts mainly include temperature programmed reduction (TPR), phosphine reduction, hydrogen plasma reduction, thermal decomposition, solvothermal method and chemical plating method.

[0038] Temperature programmed reduction (TPR) is the most common method for the preparation of nickel phosphide. This method usually uses (NH4)2HPO4 as phosphorus source and Ni(NO3)2 as nickel source. The typical preparation process is as follows: first, the nickel source and phosphorus source are mixed and dissolved, dilute nitric acid is added, and the solution is stirred until it is clear, then evaporated to dryness and calcined to obtain a nickel-phosphorus oxidation state precursor; then, the precursor is reduced in H2 atmosphere at high temperature of 400-1000℃ for several hours to obtain Ni2P catalyst. The following publications all involve the preparation of Ni2P catalyst by TPR method: J. Catal., 2002, 209(1): 1-5., J. Catal., 2002, 208(2): 321-331, 456-466., J. Catal., 2003, 215(2): 208-219., J. Catal. 2003, 216(1-2): 343-352., J Catal, 2005, 231(2): 300-313., Catal. Today, 2009, 143(1): 94-107., J. Catal., 2009, 263(1): 4-15., Appl. Catal. B Environmental, 2012, 113-114(none): 87-99., ACS Catal., 2012, 2(4): 592-598., Fuel Chem. J., 2014, 42(6): 733-737., RSC advances, 2016, 6(36): 30372-30383., Green Chem., 2018, 20(3)., RSC advances, 2019, 9(27): 15488-15494., Ind. & Eng. Chem. Res., 2020, 59: 7416-7425., Angew. Chem. Int. Ed., 2021., J. Ind. Eng. Chem., 2021, 95: 376-387. Among them, the publication Green Chem., 2018, 20: 609-619. reported the catalytic performance of Ni3P catalyst prepared by TPR method in the hydrogenation of phenol. Studies have shown that Ni3P catalyst can exhibit high hydrogenation activity at relatively low temperature (150-250℃) to convert phenol to cyclohexanol and a small amount of cyclohexanone. In contrast, under the same reaction conditions, the conversion rate of phenol hydrogenation reaction catalyzed by noble metal catalyst Pd / SiO2 is lower, and the amount of by-product cyclohexanone generated is large. The low-temperature hydrogenation activity of Ni3P catalyst is higher than that of noble metal catalyst Pd / SiO2, which once again indicates that metal phosphides have noble metal-like properties as catalysts.The document Catal. Today, 2019, 319: 48-56 reports a series of SiO2 supported nickel phosphide catalysts prepared by TPR method and their catalytic performance in the hydrodeoxygenation of phenol in aqueous phase. The preparation method of the SiO2 supported nickel phosphide catalyst is as follows: the catalyst precursor is prepared by using equal volume impregnation method, such as 1.2 g of Ni(NO3)2·6H2O and 0.2 g of (NH4)2HPO4 are dissolved in 1.0 mL of dilute nitric acid at room temperature, and are added dropwise to 1.0 g of SiO2 carrier under constant stirring, and are left overnight, and are dried in an oven at 120°C for 12 h, and are calcined in a muffle furnace at 500°C for 3 h to obtain the catalyst precursor, and then the precursor is converted into a nickel phosphide catalyst by H2 temperature programmed reduction (TPR) method. The XRD results show that when the addition amount of nickel source and phosphorus source is 3 in terms of Ni / P, the crystalline phase of the obtained catalyst is Ni3P; when the addition amount of nickel source and phosphorus source is 2 in terms of Ni / P, the crystalline phase of the obtained catalyst is mainly Ni. 12 P5; and when the addition amount of nickel source and phosphorus source is 1 in terms of Ni / P, the crystalline phase of the obtained catalyst is Ni2P. The three kinds of nickel phosphide all exhibit high conversion rate in the reduction reaction of phenol, and the product is mainly cyclohexanol in a lower temperature range, and the order of catalytic activity is Ni3P > Ni 12 P5 > Ni2P. Ni3P / SiO2 can make phenol completely converted at above 200°C. The main disadvantage of the TPR method is that the reduction temperature is too high, and high temperature is easy to make the grain size of nickel phosphide too large. In addition, the TPR method will cause the loss of phosphorus, making it difficult to control the ratio of metal and phosphorus.

[0039] The phosphine reduction method is a method for preparing a nickel phosphide catalyst by treating a metal or metal oxide particle with phosphine (PH3) at a suitable temperature. The first report on the preparation of various supported metal phosphides using PH3as a phosphorus source was published in J. Amer. Chem. Soc, 1974, 96(11): 3410-3415. The researchers reacted 25 mol% PH3 / H2mixed gas with metal precursors (chlorides of Fe, Co, Ni, Mo, W, Rh, Pd, Ru, and Pt) supported on alumina (reaction temperature 250-300°C), but the prepared catalysts had low hydrogenation activity. Chem. Commun., 2005, (33): 4178-4180. reported the preparation of nickel phosphide on silica and alumina supports using the above method. The results showed that the phosphine reduction method can be used to prepare supported nickel phosphide catalysts at moderate temperatures, and the crystallite size of the catalysts is related to the dispersion of the precursors. It is worth mentioning that when preparing nickel phosphide using the phosphine reduction method, even when using alumina as the support, a low-loading supported metal phosphide catalyst with high dispersion and high activity can be prepared. In this sense, the phosphine reduction method is superior to the TPR method. However, PH3used in the phosphine reduction method is highly toxic and flammable, making it difficult to industrialize. The following publications and patents relate to the preparation of nickel phosphide catalysts using the phosphine reduction method: J. Catal., 2002, 208(2): 456-466., J. Catal., 2005, 229(3): 314-321., J. Catal., 2006, 237(1): 118-130., Catal. Today, 2007, 125(3-4): 137-142.

[0040] To overcome the disadvantage of using toxic gas directly in phosphine reduction method, in recent years, people use hypophosphite as phosphorus source to produce phosphine by in-situ thermal decomposition method to reduce metal oxide, which is the process of preparing nickel phosphide catalyst by thermal decomposition method. Specifically, thermal decomposition method is to use hypophosphite (such as NaH2PO2) to produce PH3 by dismutation reaction in neutral or acidic environment, and then use the strong reducing property of PH3 to prepare nickel phosphide catalyst. In the thermal decomposition method, Ni(NO3)2 and NiCl2 are usually used as Ni source. The following documents all involve the preparation of nickel phosphide catalyst by thermal decomposition method: J. Catal., 2009, 263(1): 1-3, published document J. Catal., 2009, 263(1): 1-3, J. Catal., 2010, 271(2): 413-415, Appl. Catal. A, 2013: 462-463, RSC Adv, 2015, 5: 38774-38782, Appl. Catal. A: General, 2015, 505: 267-275, Catal. Commun, 2016, 77: 13-17, New J. Chem., 2018, 42(24): 19917-19923, Int. J. Chem. Reac. Eng., 2019, 17(12), and ACS Omega, 2020, 5(48): 31423-31431. The typical method for preparing nickel phosphide by thermal decomposition method is as follows: a certain amount of nickel source (such as NiCl2) and NaH2PO2 is dissolved in water, and the mixture is uniformly mixed to obtain a clear solution. Then the mixed solution is used to impregnate the carrier (such as Al2O3, MCM-41, etc.). Next, the precursor of the catalyst is dried at low temperature (such as 80°C for 8h). Then the precursor is reduced by calcination under argon environment (can be calcined at 300°C for 30min). Finally, the impurity ions in the obtained product are removed by washing with water, and after drying, the supported nickel phosphide (Ni2P) catalyst can be obtained. Compared with TPR method, the catalyst prepared by this method can greatly improve the hydrogenation activity. However, if the catalyst prepared by this method is used at a reaction temperature higher than 500°C, the activity will be significantly reduced due to sintering of the catalyst. In general, although the thermal decomposition method is an improvement over the phosphine reduction method, it has not fundamentally eliminated PH3 gas.

[0041] Hydrogen plasma reduction method refers to a method for reducing phosphate precursors made of metal oxides and phosphates to prepare phosphide catalysts by placing the transition metal phosphate precursors in a plasma reactor, introducing hydrogen gas, and then making hydrogen plasma under a high voltage of 10-20 kV to discharge hydrogen. Chinese patent CN101011664 (2007-01-09) discloses a method for preparing Ni2P catalysts by hydrogen plasma reduction method. In addition, the following publications all involve the preparation of phosphide catalysts by hydrogen plasma reduction method: Angew. Chem. Int. Ed, 2008. 47(32):6052-6054, J. Solid State Chem., 182(2009):1550-1555, Chem. Eng., 2015, 43(2):16-19, Mod. hem. Ind., 2016(10):80-82, Top Catal., 2017, 60:987-996, Chem. Eng., 2017, 45(3):6-9. Among them, the specific method reported in the publication Angew. Chem. Int. Ed, 2008. 47(32):6052-6054. is as follows: the catalyst precursor loaded with Ni(NO3)2 and (NH4)2HPO4 salt is placed in a quartz tube dielectric barrier discharge (DBD) plasma reactor, and the discharge reaction is carried out under the conditions of power input voltage of 70 V and reactor H2 rate of 150 mL / min for 2 h, to prepare supported Ni2P catalyst. The temperature of the catalyst bed during the discharge process is lower than 150℃. The results show that, compared with the conventional temperature programmed reduction method, the hydrogen plasma reduction method for preparing phosphide catalysts has low reduction temperature, short time, high efficiency, can avoid the adverse effects of the generation of by-product H2O on the catalyst activity in the reduction reaction, and low-temperature reduction is beneficial to the high dispersion of supported metal phosphides, which improves the hydrogenation activity. In summary, the hydrogen plasma reduction method has many advantages. Its disadvantage is high energy consumption and difficulty in engineering.

[0042] The solvothermal method refers to a method in which a reaction is carried out in a closed system (e.g., a reaction kettle) with an organic substance as a solvent, a certain pressure is generated in the solution in the reaction kettle at a specific temperature, and the reactants dissolved in the solvent are reacted. The document J. Cryst. Growth, 2009, 311(4): 1229-1233 reports a study on the preparation of a Ni2P catalyst using nickel acetylacetonate, oleic acid, tri-n-octylphosphine, and tri-n-octylamine as raw materials by the solvothermal method. However, the raw materials used in this method are expensive and the preparation process is complex. The document J. Fuel Chem. and Technol., 2015, 43(6): 714-719 reports a study on the preparation of a supported Ni2P / MCM-41 catalyst using triphenylphosphine as a phosphorus source, tri-n-octylamine as a solvent, and nickel acetylacetonate as a nickel source in a liquid reaction system. The synthesis of the catalyst was carried out at atmospheric pressure and a temperature of 330°C. The reduction temperature required by the temperature programmed reduction method (H2-TPR) is at least 300°C lower than that required by the traditional solvothermal method, and the raw materials used in the synthesis are cheaper than those used in the traditional solvothermal method. The document J. Cryst. Growth, 2008, 310(10): 2569-2574 reports a study on the preparation of a Ni2P catalyst using NiCl2·6H2O and elemental phosphorus as raw materials and urea as a pH adjuster in a mixed solution of ethylene glycol, ethanol, and water by the solvothermal method. A spherical morphology and hexagonal phase of nano-Ni2P with a particle size of about 500 nm were obtained. The following documents all involve the preparation of a nickel phosphide catalyst by the solvothermal method: Mater. Res. Bull., 1998, 33(5): 669-672, Solid State Ionics, 1999, 122(1): 157-160, J. Solid State Chem., 2000, 149(1): 88-91, Inorg. Chem., 2007, 46(2): 369-371, J. Cryst. Growth, 2007. 304(2): 430-434, J. Cryst. Growth, 2009, 311(4): 1229-1233, Ceram. Int., 2010, 36(3): 1155-1158, J. Phys. Chem. of Solids, 2011, 72(12): 1452-1456, Appl. Catal. B, 2014, 160: 344-355, Appl. Surf. Sci., 2016, 386: 442-450.

[0043] In 1844, Wurtz first discovered that hypophosphite could reduce metallic nickel from an aqueous solution. In 1943, Brenner and Riddell successfully developed a formula for a chemical nickel plating solution, and pioneered the technology of chemical nickel plating. The preparation of phosphides by chemical plating is achieved by depositing metal ions in solution after being reduced by the reducing hypophosphite ion (H2PO2 - ). It is generally believed that the process of chemical nickel plating is as follows: H2PO2 - + H2O → HPO3 2- + H + + 2H ad Ni 2+ + 2H ad → Ni + 2H + H2PO2 - + H ad → H2O + OH - + P Ni + P → amorphous Ni-P amorphous Ni-P → Ni3P

[0044] The above chemical equations show that during the process of chemical plating, the hypophosphite ion is changed into phosphite in the solution and releases atomic hydrogen. The atomic hydrogen is very active and can be adsorbed on the surface of the metal and activate it. With the generation of atomic hydrogen, the Ni 2+ ion is first reduced to form a Ni nucleus, and then an FCC (face-centered cubic) structured Ni intermediate phase. The atomic hydrogen also reduces the hypophosphite to generate P atoms. The combination of P and Ni atoms generates an amorphous Ni-P compound, which maintains a metastable structure of short-range order and long-range disorder. Under suitable conditions, the amorphous Ni-P compound is heat treated (post-treatment) to form a stable phosphide crystal structure.

[0045] In order to generate a Ni-P plating layer, a main salt, a reducing agent, a complexing agent, and a buffer are usually added to the reaction solution of chemical plating, and different components play different roles in the plating solution.

[0046] The main salt (nickel source) in the chemical plating solution is usually nickel sulfate, nickel chloride, nickel acetate, nickel nitrate, etc., and its role is to provide Ni 2+ ions. The selection of different nickel salts as the main salt in the chemical plating solution composition will affect the corrosion resistance and tensile stress of the plating layer. However, when used for preparing catalysts, different nickel salts such as nickel nitrate, nickel sulfate, nickel acetate, and nickel chloride can be used, and they can all achieve the purpose of providing Ni 2+ ions. The concentration of Ni 2+ ions in the plating solution will affect the deposition rate. In general, as the concentration of Ni 2+ ions increases, the reaction deposition rate increases. When it reaches a certain concentration, the deposition rate tends to a stable value.

[0047] The reducing agent is the most important component in the plating solution, which can reduce Ni 2+ ions in the plating solution. In electroless plating, sodium hypophosphite is usually used as the reducing agent, which has the advantages of low price and easy control of the plating solution.

[0048] There are many kinds of complexing agents that can be added to the electroless plating solution, such as sodium citrate (TSC), sodium ethylenediaminetetraacetate (EDTA), and glycine (Gly). The role of the complexing agent is to form stable complexes with Ni 2+ ions in the solution, reducing the concentration of free Ni 2+ ions in the solution. Specifically, when the system is in an alkaline environment, the complexing agent can complex with Ni 2+ ions, inhibiting the generation of Ni(OH)2precipitate. In addition, during the electroless plating process, as the concentration of H2PO3 - in the system continuously increases, nickel hypophosphite precipitate is easily generated. Adding a proper concentration of complexing agent can also prevent the generation of nickel hypophosphite precipitate.

[0049] The relationship between the buffering performance of the plating solution and the plating rate was first reported in the publication Electroplating & Pollution Control, 2003, 23(6): 19-22. The authors selected three commonly used electroless nickel plating buffer systems for testing, namely the acetic acid-sodium acetate system, the succinic acid-sodium succinate system, and the citric acid-sodium citrate system. The study showed that under the same mass concentration conditions, the acetic acid-sodium acetate buffer system has superior performance, as it can provide a pH range of 3.7-5.6, at which the plating solution has good pH stability and plating rate.

[0050] According to the report in the publication Electroplating and Finishing, 1999, 18(2): 43-46, the reaction temperature is also an important factor in the electroless nickel plating process. When the temperature is lower than 70°C, the plating rate is very slow; as the temperature increases, the plating rate significantly accelerates. When the temperature rises to around 90°C, the plating rate reaches a maximum; as the temperature continues to rise, the plating rate decreases, because the stability of the plating solution decreases and becomes turbid. Therefore, the temperature of general electroless plating should be controlled at 90±1°C.

[0051] According to existing literature reports, the preparation of phosphorus nickel by electroless plating can be divided into two methods according to the acidity or alkalinity of the plating solution. When preparing phosphorus nickel in an acidic plating solution, a buffer solution is needed, while in an alkaline plating solution, a certain amount of complexing agent needs to be added to prevent the generation of Ni 2+ ion Ni(OH)2precipitate.

[0052] A typical procedure for preparing phosphorus nickel in an acidic plating solution is to first prepare a precursor of phosphorus nickel by immersion or deposition precipitation method, and then perform phosphorization treatment on the catalyst precursor in an acidic plating solution containing a reducing agent sodium hypophosphite, which can use an acetic acid-sodium acetate buffer system. When electroless plating is performed, the plating solution is first heated to 90±1°C, and then the precursor is slowly added to the solution, and the reaction is carried out for 2-4 hours. After the reaction is stopped, the amorphous phosphorus nickel is obtained by filtration, washing and drying. Finally, the crystalline Ni3P is obtained by annealing at a high temperature of 400-500°C. The following documents all relate to the preparation of phosphorus nickel by electroless plating in an acidic environment: J. Mater. Sci., 1990, 25(5): 2573-2584, published document J. Catal., 2000, 194(2): 211-221, Chinese patent CN110215927 (application date 2019-05-24), and master's thesis “Preparation of supported phosphorus nickel hydrogenation-deoxidation catalyst by electroless plating method”. Dalian University of Technology, 2020. Among them, Chinese patent CN110215927 (application date 2019-05-24) discloses a specific method for preparing an Al2O3-supported phosphorus nickel catalyst by deposition precipitation-chemical plating process, and the performance of the prepared catalyst in biomass oil HDO reaction. The specific method for preparing the catalyst is as follows: 2.6g of Ni(NO3)2·6H2O is dissolved in 300mL of deionized water to prepare a Ni(NO3)2 solution. Then, 240mL of the solution is taken and 2.4g of Al2O3 carrier is added, and the solution is immersed at 70°C under stirring; on the other hand, 7.6g of urea is weighed and added to the remaining 60mL of Ni(NO3)2 solution. Then, 0.4mL of concentrated nitric acid is added to the solution, and the solution with added nitric acid is added dropwise to the aforementioned immersion solution at 70°C to perform deposition precipitation reaction, and after the dropwise addition is completed, the temperature is raised to 90°C and the reaction is carried out for 16h. After the reaction is completed, the product is recovered by filtration, washed with deionized water, and dried in an oven at 110°C overnight to obtain a gray-black solid, which is the precursor of the catalyst. Then, 100mL of acetic acid-sodium acetate buffer solution with pH of 5.5 is prepared, and 9.55g of sodium hypophosphite is added, and the solution is heated to 90°C under continuous stirring. Then, 1.6g of the precursor compound is slowly added to the solution within 1h to perform electroless plating reaction. After the reaction is completed, the solid product is recovered by filtration, then the solid product is washed with deionized water and dried in an oven at 120°C overnight, and the post-treatment is carried out by heat treatment at 400°C in H2 atmosphere for 2h, thereby preparing the Ni3P / Al2O3 catalyst. 0.05g of the above-mentioned catalyst is placed in a high-pressure fixed-bed tubular reactor with an inner diameter of 10mm, and the HDO reaction of phenol is carried out at 250°C and 4.0MPa. The phenol is dissolved in decalin to prepare a solution with a mass concentration of 1%, and then fed by a metering pump, and the weight hourly space velocity is 106.8h -1The phenol conversion was 99.2% and the deoxygenation rate was 91.4% when the hydrogen / oil volume ratio was 1000:1.

[0053] A typical procedure for preparing phosphorus nickel in an alkaline plating solution is as follows: first, a precursor of phosphorus nickel is prepared by an immersion method or a deposition precipitation method (using complexing agents such as sodium citrate, sodium tetraacetate, etc.), and then a plating solution with a pH of 8-11 is prepared using a reducing agent (sodium hypophosphite) and ammonia water. When chemical plating is performed, the plating solution is first heated to 90±1°C, and then the precursor is slowly added, and the reaction is performed for 2-4 h. After the reaction is completed, the solid product is recovered by suction filtration, and then the solid product is washed, dried, and heat-treated at 400-500°C to obtain a crystalline Ni3P catalyst. The following documents all relate to the preparation of phosphorus nickel by chemical plating in an alkaline environment: J. Mater. Chem. A, 2016, 4: 10925-10932., Chinese patent CN107684919 (filing date 2017-08-03), doctoral thesis “Preparation of Ni3P-based catalysts and performance of phenol hydrogenation and deoxygenation”, Dalian University of Technology, 2019, Chem. React. Eng. Technol. 2019, 36(6): 516-523., and master's thesis “Preparation of phosphorus nickel catalyst and study on selective hydrogenation of furfural”, Heilongjiang University, 2021. Among them, the publication Chem. React. Eng. Technol. 2019, 36(6): 516-523. reports the specific procedure for synthesizing a Ni3P / γ-Al2O3 catalyst using an immersion-chemical plating process, as well as the catalytic performance of the prepared catalyst in the phenol hydrogenation and deoxygenation reaction. The specific procedure for preparing the catalyst is as follows: 2.02 g of NiCl2·6H2O and 2.51 g of sodium citrate (TSC) complexing agent are dissolved in 1 mL of deionized water at room temperature, and are added dropwise to 3 g of carrier γ-Al2O3 under constant stirring, left overnight, and then dried at 120°C for 12 h to obtain a NiCl2 / γ-Al2O3 precursor. 5.4 g of NaH2PO2·H2O is dissolved in 100 mL of deionized water, heated to 90°C, and the pH is adjusted to 9-10 with ammonia water, and then the NiCl2 / γ-Al2O3 precursor is slowly added for chemical plating reaction, and the reaction is performed for 2-4 h. Next, the solid product is recovered by suction filtration and the solid product is washed and dried (dried at 120°C for 12 h) to obtain a gray-black amorphous phosphorus nickel catalyst. The amorphous phosphorus nickel catalyst is annealed at 400°C for 2 h in a H2 atmosphere to obtain a crystalline Ni3P / γ-Al2O3 catalyst. The reaction evaluation results show that the catalyst prepared under the conditions of a P to Ni molar ratio of 6 and a TSC to Ni ratio of 1 has a phenol conversion of 93.6% and a cyclohexane selectivity of 88.7% at a hydrogenation and deoxygenation reaction temperature of 250°C.

[0054] According to the report in the published literature J. Alloys Compd., 2002, 334: 192-199, a small amount of metal Ni crystal phase usually exists at low phosphorus content in the phosphorus nickel prepared by electroless plating method; but at high phosphorus content, pure Ni3P phase is finally formed, and no Ni crystal phase exists. The published literature Chem. React. Eng. Technol. 2019, 36(6): 516-523. and the master's thesis “Preparation of phosphorus nickel catalyst and research on selective hydrogenation of furfural” of Heilongjiang University, 2021. both add an acid treatment step after the heat treatment annealing of amorphous phosphorus nickel. The acid treatment step is used to completely remove the metal Ni impurities existing in the phosphorus nickel. Among them, the published literature Chem. React. Eng. Technol. 2019, 36(6): 516-523. in order to obtain pure phase Ni3P / γ-Al2O3 catalyst, the phosphorus nickel catalyst supported on γ-Al2O3 synthesized by impregnation-chemical plating process is subjected to acid treatment. The specific acid treatment method is as follows: take a certain amount of catalyst, add concentrated H3PO4 according to the acid to catalyst mass ratio of 20:1, and etch for 12 h. The experimental results show that the activity of the catalyst after phosphoric acid etching is enhanced, and higher low-temperature hydrogenation deoxidation activity is shown. At a reaction temperature of 150℃, the conversion rate of phenol is increased from 65.5% to 99.0%, and the selectivity of cyclohexane is increased from 4.5% to 10.1%; when the reaction temperature is increased to 250℃, the phenol is completely converted, and the selectivity of cyclohexane is 98.7%.

[0055] In summary, in the preparation method of phosphorus nickel, the temperature programmed reduction (TPR) reduction temperature is high, and phosphorus is easy to lose; in the phosphine reduction method, PH3 is highly toxic and easy to burn; in the pyrolysis method, PH3 is also generated and water is generated; in the hydrogen plasma reduction method, the reduction temperature is low, the time is short, the efficiency is high, but the energy consumption is too large, and the preparation method will encounter engineering problems in industrial application; the solvothermal method has a complex preparation process and is easy to appear aggregation phenomenon. Compared with the above, the electroless plating method for preparing phosphorus nickel catalyst has the following advantages: (1) easy to accurately control the nickel-phosphorus ratio, synthesize more stable Ni3P catalyst; (2) the reaction system is a liquid phase reaction, and the required reaction conditions are relatively mild; (3) the carrier applicability is wide, and the electroless plating can be carried out on the surface of various carriers; (4) reduce the particle size of the catalyst and improve the dispersion. SUMMARY

[0056] The purpose of the present application is to provide a preparation method of HY zeolite supported phosphorus nickel catalyst for benzene hydrogenation alkylation reaction and its application.

[0057] The technical features of the present application mainly lie in that the provided HY zeolite supported phosphorus nickel catalyst for benzene hydroalkylation reaction is a bifunctional catalyst with metal catalysis and solid acid catalysis. The metal catalysis is provided by the supported phosphorus nickel component, which is used to catalyze the selective hydrogenation of benzene to form cyclohexene in the benzene hydroalkylation reaction; the solid acid catalysis is provided by the proton acid center inherent in the HY zeolite carrier itself, which is used to catalyze the alkylation of cyclohexene and benzene to synthesize cyclohexylbenzene in the benzene hydroalkylation reaction. So far, there is no catalyst related to phosphorus nickel in the invention patents and other documents related to the synthesis of cyclohexylbenzene by benzene hydroalkylation.

[0058] In addition, the technical features of the present application also lie in that the preparation method of the provided HY zeolite supported phosphorus nickel catalyst is divided into two steps: the first step is to prepare the precursor of the catalyst, i.e. the divalent nickel ion supported by the HY zeolite; the second step is to perform phosphorization treatment on the precursor of the catalyst, i.e. the divalent nickel ion supported by the zeolite, by using the chemical plating method.

[0059] Although the catalyst precursor, i.e. zeolite-supported divalent nickel ions, can be reduced by direct hydrogen treatment or by first converting the catalyst precursor, i.e. zeolite-supported divalent nickel ions, into zeolite-supported nickel oxide form by high-temperature calcination treatment and then hydrogen reduction treatment, the zeolite-supported metallic nickel catalyst with good catalytic effect on the benzene hydroalkylation reaction can also be prepared, and such catalyst as a catalyst for benzene hydroalkylation reaction and its benefits, including significant cost advantage, have been disclosed by many invention patents and other literatures (for example: J. Catal., 1969, 13(4): 385-396, Petrochem. Techno., 2015, 44(2): 175-180, Fine Chem., 2017, 34(10): 1161-1168, ACTA PETROL SIN: PET PROCESS SECTION, 2019, 35(6): 1067-1076., ACTA PETROL SIN: PET PROCESS SECTION, 2023, 39(2): 340-348., etc.), but people skilled in the art know that the catalytic activity of the zeolite-supported metallic nickel catalyst is much lower than that of the zeolite-supported noble metal catalyst. In particular, the inventors found through research that the zeolite-supported metallic nickel catalyst has poor selectivity in the reaction of benzene hydroalkylation to synthesize cyclohexylbenzene, and generates more methylcyclopentane and methylcyclopentylbenzene. Methylcyclopentane and methylcyclopentylbenzene are both products of isomerization side reactions. Compared with the catalyst supported by noble metals, the catalyst supported by non-noble metals nickel has more serious isomerization side reactions. As known, methylcyclopentylbenzene and cyclohexylbenzene are structural isomers with very small difference in boiling point, and it is difficult to separate them as by-products and main products of benzene hydroalkylation reaction. According to the description in patent WO2015 / 094 952A1, when cyclohexylbenzene is oxidized to synthesize phenol and cyclohexanone, the content of methylcyclopentylbenzene in the cyclohexylbenzene feedstock should be no more than 0.5 wt.%, otherwise the product quality of phenol and cyclohexanone is poor and the use is limited. The inventors found through a large number of researches that the catalyst precursor, i.e. zeolite-supported divalent nickel ions, can be converted into zeolite-supported phosphatized nickel by phosphatizing treatment, and then used as a catalyst for benzene hydroalkylation reaction, which can significantly improve the selectivity of the main product cyclohexylbenzene and significantly inhibit the generation of isomerization by-products methylcyclopentane and methylcyclopentylbenzene. Overall, the catalytic activity and selectivity of the zeolite-supported phosphatized nickel catalyst are superior to those of the zeolite-supported metallic nickel catalyst, and can be comparable to those of the zeolite-supported noble metal (such as Pt, Ru, Pd). Therefore, compared with the zeolite-supported noble metal and the zeolite-supported non-noble metal (zeolite-supported metallic nickel), the zeolite-supported phosphatized nickel as a catalyst for benzene hydroalkylation to synthesize cyclohexylbenzene has obvious industrial application value.

[0060] Specifically, the HY zeolite supported phosphorus nickel catalyst provided by the present application is a HY zeolite supported rich-metal phosphorus nickel catalyst.

[0061] More specifically, the HY zeolite supported phosphorus nickel catalyst provided by the present application is a HY zeolite supported Ni3P catalyst.

[0062] In addition to Ni3P, Ni2P is also a very important rich-metal phosphorus nickel catalyst. The catalytic performance of the HY zeolite supported Ni2P catalyst in the benzene hydroalkylation reaction is also obviously superior to that of the HY zeolite supported metal nickel catalyst. However, in view of the fact that the thermal stability and hydrothermal stability of the zeolite supported Ni2P catalyst are not as good as those of the zeolite supported Ni3P catalyst, and the preparation conditions of the zeolite supported Ni3P catalyst are mild and the method is simple and easy to implement, the HY zeolite supported phosphorus nickel catalyst provided by the present application is a phosphorus nickel catalyst in which Ni3P is the main existing form.

[0063] As mentioned above, the HY zeolite support itself has protonic acid centers and can provide solid acid catalysis for the alkylation of cyclohexene and benzene in the HY zeolite supported phosphine nickel catalyst provided by the present application. However, it is known to those skilled in the art that "zeolite" refers to a crystalline material having regular channels. So far, there are more than 250 types of zeolite materials classified according to topological structure types, and the crystal structure and channel data of each type of zeolite can be found in the database of the International Zeolite Association (IZA) (http: / / www.iza-structure.org / databases / ). Among them, many zeolites such as Beta, FAU (X, Y), MOR (Mordenite) and MCM-22 family, either as independent solid acid catalysts or as zeolite supports for noble metal or / and non-noble metal hydrogenation components with solid acid catalytic function, have appeared in invention patents and other documents related to the synthesis of cyclohexylbenzene by benzene hydroalkylation. Among them, the MCM-22 family of zeolites, also known as MWW zeolites, actually includes MCM-22, MCM-36, MCM-49 and MCM-56, etc. These zeolite materials that have appeared in invention patents and other documents related to the synthesis of cyclohexylbenzene by benzene hydroalkylation can be used to support the phosphine nickel described in the present application to make bifunctional catalysts for benzene hydroalkylation, just from the catalytic function. The present application selects HY zeolite as the support for loading the phosphine nickel hydrogenation component, which is due to the following advantages of HY zeolite: (1) low price; (2) easy to obtain; (3) open channel system, which is more suitable for loading phosphine nickel in the zeolite channels; (4) appropriate acid center density and strength; (5) unique channel system and acidity, which is beneficial to prepare a bifunctional catalyst with a zeolite supported phosphine nickel with a closer distance between the hydrogenation active center and the alkylation active center, and higher activity, selectivity and stability in the synthesis of cyclohexylbenzene by benzene hydroalkylation.

[0064] The reaction of benzene hydroalkylation to synthesize cyclohexylbenzene has the following characteristics: (1) The main reaction is a series of benzene hydrogenation to cyclohexene and cyclohexene alkylation with benzene to form cyclohexylbenzene. In thermodynamics, since both steps are exothermic, reducing the reaction temperature is beneficial to the synthesis of cyclohexylbenzene. So far, the upper limit of the reaction temperature used in the relevant invention patents and other documents is 250°C, and the lower limit is 110°C. Among them, when the bifunctional catalyst contains noble metal, a lower reaction temperature is usually used, and when the bifunctional catalyst only contains non-noble metal, a higher reaction temperature is usually used; (2) According to the literature reports and the research results of the inventors, the benzene hydroalkylation reaction generates not only the target product cyclohexylbenzene (C 12) in addition to the above, the following main by-products are also generated: i.e. cyclohexane (C6), methylcyclopentane (C6), cyclohexylcyclohexane (C 12 ), isomeric mixture of methylcyclopentylbenzene (C 12 ) and dicyclohexylbenzene (C 18 mixture). Among them, the generation of methylcyclopentylbenzene is due to the isomerization of benzene to form a methylcyclopentene intermediate during the hydrogenation reaction of benzene on the metal center, and the latter reacts with benzene to form alkylization; or due to the isomerization of cyclohexene generated by the hydrogenation of benzene to form a methylcyclopentene intermediate, and the latter reacts with benzene to form alkylization. That is, the methylcyclopentene intermediate is the direct cause of the generation of methylcyclopentylbenzene, and the isomerization reaction (to form the methylcyclopentene intermediate) on the metal functional catalytic center and the acid functional catalytic center of the bifunctional catalyst is the fundamental cause of the generation of methylcyclopentylbenzene. As for the generation of cyclohexane, methylcyclopentane, cyclohexylcyclohexane and isomeric mixture of dicyclohexylbenzene, it is relatively easy to understand. Among them, cyclohexane, methylcyclopentane and cyclohexylcyclohexane are due to the hydrogenation saturation of cyclohexene, methylcyclopentene and cyclohexylbenzene on the metal functional catalytic center of the bifunctional catalyst, respectively, and the isomeric mixture of dicyclohexylbenzene is due to the alkylization of cyclohexylbenzene and cyclohexene on the acid functional catalytic center of the bifunctional catalyst.

[0065] The inventors have also found that the synthesis of cyclohexylbenzene by benzene alkylation with hydrogen requires a high degree of synergy between the metal catalysis and the solid acid catalysis of the bifunctional catalyst. In other words, the formation of the target product cyclohexylbenzene is the result of the close cooperation and concerted action of the metal functional catalytic center and the acid functional catalytic center of the bifunctional catalyst to promote the two consecutive reactions. However, in the following cases, the metal functional catalytic center and the acid functional catalytic center of the bifunctional catalyst cannot perform synergistic catalysis, which results in an increase in the amount of by-products and an accelerated deactivation of the catalyst: (1) the metal functional catalytic center is far away from the acid functional catalytic center. In this case, the cyclohexene generated by the hydrogenation of benzene and hydrogen on the metal functional center has to undergo a long-distance diffusion and migration after leaving the metal functional center before reaching the acid functional catalytic center for benzene alkylation. In this process, on the one hand, the probability of the cyclohexene being captured again by the metal functional catalytic center of the catalyst and being hydrogenated to cyclohexane increases, which will increase the amount of cyclohexane by-product and thus reduce the selectivity of cyclohexylbenzene. On the other hand, the possibility of cyclohexene polymerization increases, which will accelerate the coking deactivation of the catalyst; (2) a part of the metal functional catalytic centers have high coordination unsaturation and strong metal properties. In this case, the hydrogenation of benzene and hydrogen not only easily generates more complete hydrogenation product - cyclohexane, but also easily undergoes metal-catalyzed isomerization to generate methylcyclopentene and methylcyclopentane. Among them, methylcyclopentene can also undergo alkylation with benzene on the acid functional catalytic center to generate methylcyclopentylbenzene; (3) a part of the solid acid functional catalytic centers have too strong acid strength. In this case, on the one hand, acid-catalyzed cyclohexene isomerization easily occurs, resulting in methylcyclopentene and methylcyclopentylbenzene. On the other hand, since cyclohexylbenzene is easily strongly adsorbed on strong acid centers, the probability of multi-alkylation of cyclohexylbenzene increases. This will increase the amount of dicyclohexylbenzene isomers, and even increase the amount of coking products with a boiling point higher than that of dicyclohexylbenzene isomers. The former will reduce the selectivity of cyclohexylbenzene, and the latter will accelerate the coking deactivation of the catalyst.

[0066] The inventors have realized through a large number of experimental studies that the use of HY zeolite as a carrier is conducive to the preparation of a zeolite-supported nickel phosphide catalyst with good synergistic catalysis.

[0067] First, the HY zeolite has a three-dimensional intersecting channel feature and its channel opening is a large 12R (12-ring) pore. Furthermore, there is a supracage in the HY zeolite. The supracage in the HY zeolite is a geometric space that is more open than the channel opening of the 12R. The above channel feature of the HY zeolite is advantageous for avoiding the metal function catalytic center (the phosphide nickel component, more specifically, the phosphide nickel component in the form of Ni3P as the main existing form) in the HY zeolite-supported phosphide nickel catalyst from being far away from the acid function catalytic center. This is because, as mentioned above, the preparation method of the HY zeolite-supported phosphide nickel catalyst provided by the present application has the technical feature that the entire preparation process is divided into two steps: the first step is used to prepare the precursor of the catalyst, i.e., the HY zeolite-supported divalent nickel ion, and the second step is used to perform phosphorization treatment on the precursor of the catalyst, i.e., the HY zeolite-supported divalent nickel ion. Among them, the first step of preparing the HY zeolite-supported phosphide nickel catalyst is a very critical step. Because in this step, the main challenge often encountered is that when the divalent nickel ion is loaded by the impregnation method, it is difficult for the divalent nickel ion to enter the interior of the zeolite crystal, and most of the nickel salt is impregnated on the outer surface of the zeolite crystal. This is the main reason for the catalyst that most of the metal function catalytic centers are far away from the inherent acid function catalytic centers in the zeolite channel. Relatively speaking, the HY zeolite benefits from its networked channel system and open intracrystalline space, and the nickel salt is more likely to enter its crystal interior during the impregnation process.

[0068] Secondly, the reason why the HY zeolite is favorable to the preparation of the zeolite supported phosphorus nickel catalyst with good synergistic catalytic effect is that the HY zeolite has suitable inherent acidity. As is known to those skilled in the art, the inherent acidity of the zeolite carrier includes two meanings of acid strength (the ability of the proton acid center to provide protons) and acid density. The proton acid center of the zeolite carrier is derived from the bridged hydroxyl group on its framework. One framework aluminum produces one bridged hydroxyl group. Therefore, the acidity of the zeolite carrier is closely related to the aluminum content of its crystal framework, i.e. the silicon-aluminum ratio. The silicon-aluminum ratio of the zeolite carrier can be expressed by the molar ratio of silicon oxide and aluminum oxide, or the molar ratio of silicon atoms and aluminum atoms. Generally speaking, the acid density of the zeolite with a low silicon-aluminum ratio is high, but the acid strength is low. Conversely, the acid strength of the zeolite with a high silicon-aluminum ratio is high, but the acid density is low. When Y zeolite is synthesized by the hydrothermal method, Y zeolite with a SiO2 / Al2O3 molar ratio of 5-6 is most easily obtained. It is relatively difficult to obtain pure Y zeolite with a SiO2 / Al2O3 molar ratio higher than 6 or lower than 5 by the hydrothermal synthesis method. Because the hydrothermal synthesis of Y zeolite with a SiO2 / Al2O3 molar ratio lower than 5 is prone to produce A-type zeolite impurities, and the hydrothermal synthesis of Y zeolite with a SiO2 / Al2O3 molar ratio higher than 6 is prone to produce P-type zeolite impurities. The inventors found in the research on the HY zeolite carrier that when the HY zeolite with a high silicon-aluminum ratio (i.e. USY. The HY zeolite is generally subjected to steam treatment to achieve the ultrastabilization by partially removing aluminum from the framework) is used as the carrier, and when the HY zeolite with a high silicon-aluminum ratio obtained by the silicon tetrafluoride dealumination and silicon supplementation method is used as the carrier, the catalytic performance of the zeolite supported phosphorus nickel catalyst in the benzene hydrogenation alkylation reaction is not as good as that of the catalyst prepared by directly using the HY zeolite with a relatively low silicon-aluminum ratio obtained by the hydrothermal method as the carrier. The reason is that the acidity of the USY zeolite and the high-silicon HY zeolite is relatively low, resulting in the weak acid catalysis of the zeolite supported phosphorus nickel catalyst, which cannot meet the requirement of the synergistic catalysis of the zeolite supported phosphorus nickel catalyst. Interestingly, when we tried to prepare the zeolite supported phosphorus nickel catalyst by using the HX zeolite with a very low silicon-aluminum ratio as the carrier, it was found that the catalytic performance of the prepared catalyst in the benzene hydrogenation alkylation reaction was also not as good as that of the bifunctional catalyst prepared by using the HY zeolite as the carrier. The reason is also that the acidity of the HX zeolite is relatively low, resulting in the weak acid catalysis of the zeolite supported phosphorus nickel catalyst, which cannot meet the requirement of the synergistic catalysis of the zeolite supported phosphorus nickel catalyst. Obviously, the reason why the HX zeolite has low acidity is different from that of the USY zeolite and the high-silicon HY zeolite. As is known to those skilled in the art, the framework topology of the HX zeolite is the same as that of the HY zeolite, i.e. the faujasite (FAU) topology. However, the molar ratio of silicon oxide (SiO2) and aluminum oxide (Al2O3) of the HX zeolite is very low, between 2 and 3. The reason why the HX zeolite has low acidity is exactly because the framework silicon-aluminum ratio of the HX zeolite is very low, and the aluminum content is too high. The very low framework silicon-aluminum ratio and the too high aluminum content result in the low electronegativity of the framework of the HX zeolite, and thus the ability of the bridged hydroxyl group to provide protons, i.e. the strength of the acid center, is weakened.

[0069] In addition, we also recognize through a large number of experimental studies that the preparation of zeolite supported phosphorus nickel catalyst with HY zeolite as the carrier can also provide efficient diffusion channels for the main and by-products generated by the benzene hydrogenation alkylation reaction. The benzene hydrogenation alkylation synthesis of cyclohexylbenzene is a molecular number reducing reaction, and generally speaking, the use of pressurized reaction conditions is beneficial to the synthesis of cyclohexylbenzene. According to our statistics, the upper limit of the reaction pressure used in the related invention patents and other literatures is 4.0 MPa, and the lower limit is 1.0 MPa. Among them, when the dual functional catalyst contains noble metal, the reaction pressure range commonly used is 2.0-4.0 MPa. When only non-noble metal is used in the dual functional catalyst, the reaction pressure range commonly used is 1.0-2.0 MPa. In view of the fact that in the benzene hydrogenation alkylation synthesis of cyclohexylbenzene, in addition to the difficult-to-liquefy reactant-hydrogen (boiling point-252.8℃), there are also liquefiable low-boiling-point reactants benzene (boiling point 80.1℃) and low-boiling-point products cyclohexane (boiling point 80.7℃), methylcyclohexane (boiling point 71.8℃), and easily liquefiable high-boiling-point products cyclohexylbenzene (boiling point 238-240℃), methylcyclopentylbenzene (estimated boiling point 238-240℃), cyclohexylcyclohexane and a mixture of dicyclohexylbenzene isomers (boiling point close to 200℃ at 13 mmHg), it can be imagined that the reaction under suitable temperature and pressure conditions belongs to the gas-liquid-solid three-phase catalytic reaction mode. Or roughly speaking, the reaction under suitable temperature and pressure conditions is mainly carried out in a liquid-solid phase reaction mode, and the effects of external diffusion and internal diffusion limitations on reaction conversion and selectivity are very serious. However, when HY zeolite is used as the carrier of the catalyst, its networked pore system and open intracrystalline space are beneficial to reducing the mass transfer resistance of molecular diffusion under liquid-solid phase reaction conditions.

[0070] Technical scheme of the present application:

[0071] The preparation method of the HY zeolite supported phosphorus nickel catalyst for benzene hydrogenation alkylation reaction is as follows:

[0072] First step: preparation of catalyst precursor, i.e. HY zeolite supported divalent nickel ions by equal volume impregnation method

[0073] In the catalyst precursor, the weight percentage content of divalent nickel ions calculated based on metal nickel is in the range of 0.5-30wt.%, preferably in the range of 1.0-25wt.%, and more preferably in the range of 1.5-20wt.%. The specific preparation steps of the catalyst precursor are as follows:

[0074] (1) NaY zeolite as the matrix, HY zeolite carrier is prepared by the conventional ammonium exchange method. The suitable sodium content (calculated as Na2O) of the prepared HY zeolite carrier is ≤3.8 wt.%, preferably the sodium content is ≤2.0 wt.%, more preferably the sodium content is ≤0.5 wt.%.

[0075] The NaY zeolite matrix refers to the commercially available conventional hydrothermally synthesized ordinary NaY zeolite, and the SiO2 / Al2O3 molar ratio is generally 5-6. The present application does not limit the grain size of the NaY zeolite matrix. Micron-sized large-grained NaY zeolite (grain size ≥1 micron), nano-sized NaY zeolite (grain size ≤100 nanometers), and small-grained NaY zeolite with grain size between the two can be used to prepare the acidic (hydrogen type) zeolite carrier of the present application. In addition, the NaY zeolite matrix used in the present application can be commercially available or hydrothermally synthesized by oneself. If the NaY zeolite matrix is hydrothermally synthesized by oneself, the following patent applications can be referred to: US3639099 (1972), CN85102733 (1989), CN1081425A (1994), CN1160676A (1997), CN1176848A (1998), CN1354134A (2002), CN1286723C (2003), CN1621349A (2003), CN1785807A (2004), CN1785808A (2004), CN1789125A (2004), CN101254929A (2008), CN101767799A (2008), CN101177281 (2008), CN102050468A (2009), CN102050469A (2009), CN101549874A (2009), CN101468802A (2009), CN102198950A (2010), CN101870478A (2010), CN103896303A (2012), CN104743572 (2013).

[0076] It is common knowledge for people skilled in the art to prepare HY zeolite from NaY zeolite matrix by ammonium exchange. Engineers skilled in the art can prepare HY zeolite carrier from NaY zeolite matrix according to their experience or the conventional ammonium exchange method recorded in the literature. The conventional ammonium exchange method recorded in the following literature can be referred to: CN111085251A (2018), CN109772432A (2019), CN114130424A (2020), CN114130420A (2020).

[0077] However, it should be noted that all sodium ions (Na +), nearly 30% of which are located in the center of the very difficult-to-exchange hexagonal prism cage (S I positions, only about 70% of the sodium ions are located in the center of the six-membered ring inside the sodalite cage (S II positions, and inside the supercage (S III positions). Therefore, in the ammonium exchange process for preparing HY zeolite from NaY zeolite, it is generally necessary to take measures of alternately performing ammonium exchange and calcination treatment to obtain HY zeolite with low sodium content. As is known to those skilled in the art, in actual work, processes such as "two exchanges and one calcination", "two exchanges and two calcinations", "three exchanges and two calcinations", "four exchanges and two calcinations", and "four exchanges and three calcinations" are generally used to prepare HY zeolites with different sodium contents. In the ion exchange process for preparing HY zeolite described above, the intermediate calcination treatment is intended to migrate the difficult-to-exchange sodium ions to the easily exchangeable cation sites.

[0078] Since the HY zeolite has strong hydrophilicity and poor hydrothermal stability of the framework, in the ammonium exchange process for preparing HY zeolite, the high-temperature conditions used in the intermediate calcination treatment and the hydrothermal environment caused by the release of water vapor can easily lead to dealumination of the HY zeolite framework and destruction of the crystal structure. Therefore, special attention should be paid to the fact that the experience of passivating the acidity of HY zeolite and obtaining structure-ultrastabilized HY zeolite (USY) by dealuminating HY zeolite in a high-temperature hydrothermal environment in the preparation of fluidized-bed catalytic cracking (FCC) catalysts for petroleum refining is not suitable for use in the present application. Because the HY zeolite whose acidity has been passivated is not suitable for use as a catalyst carrier for high-selectivity benzene alkylation. Therefore, in the preparation of the HY zeolite carrier required by the present application by the ammonium exchange method, it is necessary to avoid the destruction of the crystal structure and dealumination of the framework of the HY zeolite caused by the high-temperature hydrothermal environment of the HY zeolite in the intermediate calcination step of the ammonium exchange. The practice of fully drying the HY zeolite before calcination treatment, and using thin-layer calcination, low-temperature calcination, and timely removal of the released water vapor during calcination are simple and effective avoidance methods.

[0079] In the preparation of a HY zeolite carrier with low sodium content by the ammonium exchange method, the present application recommends the following heat treatment steps: first, a sufficient drying pretreatment, and then a calcination treatment in flowing dry air. The most suitable condition range for the drying pretreatment is a temperature of 110-170°C and a time of 6-24h; the most suitable condition range for the calcination treatment in flowing dry air is:

[0080] Calcination temperature: 450-550°C;

[0081] Calcination time: 3-12h;

[0082] Dry air flow: 1000-5000h -1(Volumetric air space velocity, defined as the volume of air passing over the zeolite per unit time per unit volume, based on the ideal gas)

[0083] The intermediate product after calcination should be stored in a sealed container for later use, to prevent moisture absorption and repeated calcination.

[0084] (2) Preparation of the impregnation solution of divalent nickel ions. First, the saturated water absorption of the HY zeolite support after calcination is determined. Then, based on the saturated water absorption of the zeolite support and the desired loading of divalent nickel ions (in terms of metallic nickel) of the catalyst precursor to be prepared (the loading of nickel ions of the catalyst precursor is equivalent to the nickel content of the finished catalyst of HY zeolite supported nickel phosphide), the volume of the impregnation solution and the concentration of divalent nickel ions required for the equal-volume impregnation are calculated. On this basis, the required impregnation solution is prepared.

[0085] If the concentration of nickel ions of the required impregnation solution exceeds the maximum solubility of divalent nickel ions, the equal-volume impregnation needs to be changed to multiple equal-volume impregnations.

[0086] The divalent nickel ions are provided by a water-soluble nickel salt. Suitable nickel salts that provide divalent nickel ions include one or more of nickel chloride, nickel nitrate, nickel sulfate, and nickel acetate, preferably nickel chloride, nickel nitrate, and nickel acetate.

[0087] (3) Equal-volume impregnation of the HY zeolite support with the prepared impregnation solution of divalent nickel ions. Suitable impregnation conditions range from 25°C (room temperature) to 95°C for 0.5h to 24h; preferred impregnation conditions range from 30°C to 90°C for 1h to 12h; more preferred impregnation conditions range from 40°C to 80°C for 2h to 6h.

[0088] (4) Drying post-treatment of the impregnated material to obtain the precursor of the catalyst, i.e., the HY zeolite supported divalent nickel ions.

[0089] Suitable drying post-treatment conditions range from 80°C to 250°C for 1h to 96h;

[0090] Preferred drying post-treatment conditions range from 90°C to 200°C for 3h to 72h;

[0091] More preferred drying post-treatment conditions range from 110°C to 170°C for 6h to 24h;

[0092] It should be noted that if the preparation of the catalyst precursor (HY zeolite supported divalent nickel ions) requires multiple equal-volume impregnations, the impregnated material needs to be dried after each equal-volume impregnation before the next equal-volume impregnation.

[0093] Second step: using sodium hypophosphite as reducing agent, the catalyst precursor is prepared by phosphating treatment of HY zeolite loaded phosphorus nickel catalyst

[0094] The chemical plating is carried out in an acidic plating solution, and the specific method is as follows:

[0095] (1) Selecting a pH buffer solution

[0096] A large amount of hydrogen protons (H + ) will be produced in the process of chemical plating reaction, which will cause the pH value of the plating solution to decrease, and is not conducive to the normal progress of chemical plating. Adding a pH buffer to the plating solution to prevent the pH value of the plating solution from changing too much during the chemical plating reaction is a common practice in the field of chemical plating.

[0097] The suitable pH value range of the plating solution required for chemical plating in an acidic plating solution is 3.8-6.0, preferably the pH value range is 4.0-5.6, and more preferably the pH value range is 4.5-5.0.

[0098] If the pH is too low, such as when the pH < 3.8, H + will compete with Ni 2+ for discharge, which is not conducive to the reduction of Ni 2+ to generate metal (Ni). In contrast, H2PO 2- is easily reduced to P under this condition, so a pH that is too low is easy to cause the generation of phosphorus-rich nickel phosphide, rather than the metal-rich phosphide catalyst component useful for hydrogenation reaction. On the other hand, if the pH is too high, such as when the pH > 6.0, Ni 2+ will become Ni(OH)2 precipitate without a complexing agent, and the chemical plating reaction will be difficult to proceed. Although the addition of a complexing agent can prevent Ni 2+ from becoming Ni(OH)2 precipitate, it will reduce the rate of the chemical plating reaction.

[0099] Engineers familiar with the field can choose a pH buffer system according to their experience or by consulting an analytical chemistry manual. Because the pH range that the acetic acid-sodium acetate (HAc-NaAc) pH buffer system can provide is highly consistent with the suitable pH range (3.8-6.0) required for the plating solution of chemical plating, HAc-NaAc is commonly used as a buffer in an acidic chemical plating nickel system. Although the succinic acid-sodium succinate system and the citric acid-sodium citrate system can also be used as pH buffers, the acetic acid-sodium acetate buffer system has superior performance under the same mass concentration conditions, and the plating solution has good pH stability and stable deposition rate. Therefore, the use of the acetic acid-sodium acetate buffer system is recommended in the present application.

[0100] (2) Phosphating treatment of the catalyst precursor by chemical plating in the pH buffer solution:

[0101] First, the acetic acid-sodium acetate buffer solution is measured according to a certain buffer solution to catalyst precursor ratio (liquid to solid ratio, ml / g) and heated to the electroless plating reaction temperature under constant stirring.

[0102] The suitable range of the volume of the buffer solution to the amount of the catalyst precursor (liquid to solid ratio) is 5-200, the preferred range is 10-150, and the more preferred range is 15-100.

[0103] The suitable temperature range of the electroless plating reaction is 60-95°C, the preferred temperature range is 65-92°C, and the more preferred temperature range is 70-90°C.

[0104] Then, the phosphorus-nickel ratio parameter of the electroless plating solution is determined according to the amount of the catalyst precursor and the phosphorus content of the electroless plating solution (in terms of the phosphorus-nickel ratio, P to Ni molar ratio), and then the sodium hypophosphite reducing agent is added to the buffer solution under constant stirring according to the phosphorus-nickel ratio requirement of the electroless plating solution (wherein the amount of Ni is calculated based on the amount of the catalyst precursor and its nickel content), to prepare the electroless plating solution. The suitable phosphorus-nickel ratio (P to Ni molar ratio) of the electroless plating solution is in the range of 2-30, the preferred range is 3-20, and the more preferred range is 6-16.

[0105] Next, the measured catalyst precursor is slowly added to the electroless plating solution under constant stirring for phosphorization treatment.

[0106] After the catalyst precursor is added, the electroless plating reaction continues until no bubbles are generated in the plating solution, and the reaction is stopped. The electroless plating reaction that occurs during the phosphorization treatment of the catalyst precursor in the pH buffer solution is as follows: - + H2O→ HPO3 2- + H + + 2H ad Ni 2+ + 2H ad → Ni + 2H + H2PO2 - + H ad → H2O + OH - + P Ni + P→ amorphous Ni-P amorphous Ni-P→ Ni3P 2H ad → H2↑

[0107] After the electroless plating reaction is completed, the electroless plating residue is removed by filtration, the filter cake is washed with water to neutral pH (pH = 7), and then the filter cake after washing is dried for post-drying treatment to obtain the HY zeolite loaded nickel-phosphorus amorphous substance, i.e., the intermediate of the catalyst.

[0108] The suitable condition range for post-drying treatment is temperature 80-250°C and time 1-96h.

[0109] The preferred conditions for the drying post-treatment are in the range of 90-200°C for 3-72h;

[0110] The more preferred conditions for the drying post-treatment are in the range of 110-170°C for 6-24h;

[0111] (3) heat-treating the catalyst intermediate to produce a HY zeolite supported nickel phosphide catalyst

[0112] The heat-treatment is carried out in a H2 atmosphere. The suitable heat-treatment temperature, time and hydrogen flow rate (expressed in terms of hydrogen gas hourly space velocity, defined as the volume of hydrogen passing through the catalyst per unit volume per unit time, calculated as ideal gas) are in the range of

[0113] 200-700°C;

[0114] 0.2-24h;

[0115] 5-2000h -1 ;

[0116] The preferred heat-treatment temperature, time and hydrogen flow rate (expressed in terms of hydrogen gas hourly space velocity, defined as the volume of hydrogen passing through the catalyst per unit volume per unit time, calculated as ideal gas) are in the range of

[0117] 250-650°C;

[0118] 0.5-20h;

[0119] 10-1500h -1

[0120] The more preferred heat-treatment temperature, time and hydrogen flow rate (expressed in terms of hydrogen gas hourly space velocity, defined as the volume of hydrogen passing through the catalyst per unit volume per unit time, calculated as ideal gas) are in the range of

[0121] 300-600°C;

[0122] 1.5-15h;

[0123] 100-1000h -1 ;

[0124] The HY zeolite supported nickel phosphide catalyst prepared by the above method is used to catalyze the benzene hydroalkylation reaction to synthesize cyclohexylbenzene.

[0125] As mentioned above, one of the main features of the present application is that the provided zeolite supported nickel phosphide catalyst is used for the purpose of catalyzing the benzene hydroalkylation to produce cyclohexylbenzene.

[0126] But the invention is not limited to the specific process of benzene hydroalkylation to cyclohexylbenzene. So far, the benzene hydroalkylation reaction forms mentioned in the patents at home and abroad include batch reactor, fixed bed reactor and catalytic distillation. The catalyst of the invention can be applied to the above reaction modes after proper molding processing. The engineers familiar with the field can refer to the methods disclosed in the relevant patents and other literature, and prepare the corresponding catalyst form according to the catalyst preparation method provided by the invention, and implement the benzene hydroalkylation reaction. Here, the invention only implements the benzene hydroalkylation reaction in the form of the most common fixed bed reactor in the laboratory to illustrate the effect of the catalyst provided by the invention. According to the records in the existing patents and other literature, the suitable conditions for benzene hydroalkylation in a fixed bed reactor are as follows: reaction temperature 100-300℃, reaction pressure 0.5-5.0MPa, benzene feed space velocity (WHSV) 0.2-10h -1 , hydrogen-benzene molar ratio 0.1-4.0; the preferred condition range is: reaction temperature 150-250℃, reaction pressure 1.0-3.0MPa, benzene feed space velocity (WHSV) 0.4-5.0h -1 , hydrogen-benzene molar ratio 0.3-2.0.

[0127] The beneficial effects of the invention are:

[0128] The invention provides a preparation method of a zeolite-supported phosphatized nickel catalyst for benzene hydroalkylation reaction, which takes HY zeolite-supported non-noble metal nickel as a precursor, sodium hypophosphite as a reducing agent, and uses chemical plating method for phosphating treatment as a technical feature. The catalyst preparation method is simple, the preparation conditions are mild, and the raw materials used are cheap and easy to obtain. Under the same reaction conditions, the benzene hydroalkylation catalytic activity and selectivity of the HY zeolite-supported phosphatized nickel (Ni3P) catalyst are much higher than those of the HY zeolite-supported metal nickel catalyst. In particular, the amount of methylcyclopentane and methylcyclopentylbenzene isomerization by-products generated by the HY zeolite-supported phosphatized nickel (Ni3P) catalyst is much lower than that of the HY zeolite-supported metal nickel catalyst. The zeolite-supported phosphatized nickel catalyst prepared by the method of the invention can completely replace the zeolite-supported noble metal catalyst and the zeolite-supported noble metal-non-noble metal (multi-metal) catalyst in terms of catalytic performance in benzene hydroalkylation to cyclohexylbenzene. The preparation method of the zeolite-supported phosphatized nickel catalyst provided by the invention is suitable for other solid acid type zeolite carriers. BRIEF DESCRIPTION OF DRAWINGS

[0129] Figure 1 is an XRD pattern of a HY zeolite-supported phosphatized nickel catalyst (Ni3P / HY-18) with a metal nickel content of 18wt.%, which is prepared by taking HY zeolite-supported divalent nickel ions as a precursor, sodium hypophosphite as a reducing agent, and using chemical plating method for phosphating treatment;

[0130] Figure 2 is the ammonia adsorption-temperature programmed desorption (NH3-TPD) spectrum of the HY zeolite supported phosphatized nickel catalyst (Ni3P / HY-18) with a metal nickel content of 18 wt.% and its HY zeolite support, which is prepared by using divalent nickel ions supported on HY zeolite as a precursor, sodium hypophosphite as a reducing agent, and a chemical plating method for phosphatizing treatment. DETAILED DESCRIPTION

[0131] The implementation effects of the present application can be evaluated from two aspects of characterizing the physicochemical properties of the prepared HY zeolite supported phosphatized nickel catalyst and detecting its catalytic performance in the benzene hydroalkylation reaction.

[0132] In the aspect of physicochemical property characterization, the phosphatized nickel crystal phase type of the HY zeolite supported phosphatized nickel catalyst, the sodium content of the support HY zeolite, the acidity, and the crystalline retention of the crystal can be characterized.

[0133] The phosphatized nickel crystal phase type of the HY zeolite supported phosphatized nickel catalyst can be characterized by X-ray polycrystalline powder diffraction (XRD) method. The main characteristic diffraction peaks of the Ni3P crystal phase are located at 2θ = 36.4°, 41.8°, 42.8°, 43.6°, 45.3°, 46.0°, 46.6°, 47.6°, 48.1°, 52.7° (PDF #65-1605); the main characteristic diffraction peaks of the Ni2P crystal phase are located at 2θ = 40.7°, 44.6°, 47.3°, 54.1°, 54.8° (PDF #74-1385); and the characteristic diffraction peaks of the metal Ni crystal phase are located at 2θ = 44.6°, 51.9°, 76.8° (PDF #01-1260).

[0134] The sodium content of the HY zeolite support can be determined by XRF method; the acidity can be characterized by ammonia adsorption temperature programmed desorption method (NH3-TPD); and the crystalline retention of the crystal can be estimated by specific surface area data (based on NaY zeolite matrix or specific sample). The specific surface area is calculated by nitrogen physical adsorption data and BET equation.

[0135] The catalytic performance of the HY zeolite supported phosphatized nickel catalyst in the benzene hydroalkylation reaction can be evaluated by using a conventional small fixed bed reactor in the laboratory. The composition of the reaction products is analyzed offline by gas chromatography (Shimadzu GC-2014C, FID detector, PEG-20M chromatographic column (30 m x 0.32 mm x 0.5 μm)). The chromatographic conditions are as follows: column temperature 70°C, increasing to 270°C at 10°C / min, detector temperature 270°C, and sample inlet temperature 270°C.

[0136] The content of each component of the product is quantitatively calculated by area correction normalization method.

[0137] The application will be described in detail below by way of examples, but the scope of protection of the application is not limited to these examples.

[0138] Example 1: This example is used to illustrate that the zeolite-supported phosphidized nickel catalyst (Ni3P / HY) is prepared by using the non-noble metal nickel supported on HY zeolite as the precursor, sodium hypophosphite as the reducing agent, and a chemical plating method for phosphorization treatment of the catalyst precursor. The method is simple, the conditions are mild, and the raw materials used are cheap and easy to obtain. The zeolite-supported phosphidized nickel catalyst prepared has high catalytic activity and selectivity in the benzene hydrogenation alkylation reaction, and the amount of methylcyclopentane and methylcyclopentylbenzene isomerization by-product generated is small.

[0139] First step: The catalyst precursor, i.e. divalent nickel ion supported on HY zeolite, is prepared by using the equal-volume impregnation method. In the catalyst precursor, the weight percentage of divalent nickel ion calculated based on the metal nickel is 18wt.%. The specific preparation steps of the catalyst precursor are as follows:

[0140] (1) The HY zeolite carrier is prepared by a conventional ammonium exchange method using NaY zeolite as the matrix.

[0141] The NaY zeolite matrix used is a commercially available product, the sodium content (calculated as Na2O wt.%) thereof is 12.36wt.%, the SiO2 / Al2O3 molar ratio is 5.4, the crystal size is 200-300nm, and the specific surface area is 763m 2 / g.

[0142] The "four-exchange three-calcination" process is used for the ammonium exchange of the NaY zeolite matrix to prepare the HY zeolite. The "four-exchange three-calcination" process is as follows: a certain amount of NaY zeolite matrix is added to a 1.0mol / L NH4Cl solution according to a liquid-solid ratio of 10:1, and ammonium exchange is carried out at 90℃ under constant stirring for 1h. After the first ammonium exchange, the exchange solution is poured off, and the zeolite is washed with deionized water at a liquid-solid ratio of 10:1 at room temperature (25℃) for 1h, and the operation is repeated for 5 times. Then, the water-washed solid is subjected to repeated ion exchange and water washing operations as described above. Finally, the obtained zeolite filter cake is placed in an oven at 110℃ for overnight drying, and then is placed in a muffle furnace for calcination at 500℃ under flowing dry air (air volume flow rate 3000h -1 ). Thus, the "two-exchange one-calcination" HY zeolite is obtained. The "two-exchange one-calcination" HY zeolite is subjected to two more ion exchange treatments, and after each ion exchange treatment, the water washing, drying and calcination treatments as described above are carried out. Finally, the "four-exchange three-calcination" HY zeolite sample is obtained. After calcination, the HY zeolite powder product is obtained, and the sodium content thereof is 0.3wt.% as determined by XRF, and the specific surface area is 798m 2 / g, and is sealed and stored for use.

[0143] (2) Impregnation solution of divalent nickel ions is prepared with nickel acetate. First, the saturated water absorption of the HY zeolite carrier after calcination is determined to be 1.8 mL / g. 水 / 1g 载体 Then, according to the saturated water absorption of the zeolite carrier and the loading of divalent nickel ions (18 wt. % of nickel metal) of the catalyst precursor to be prepared, the volume of the impregnation solution required for the equal-volume impregnation method is calculated to be 18 ml (10 g of HY zeolite carrier, dry basis), and the concentration of nickel ions should be 1.7 mol / L. However, since the maximum solubility of nickel acetate tetrahydrate in water at room temperature is 0.73 mol / L, the equal-volume impregnation is changed to three times, and the impregnation solution used for each equal-volume impregnation is the same, with a nickel ion concentration of about 0.57 mol / L.

[0144] (3) The prepared divalent nickel ion impregnation solution is used to impregnate the HY zeolite carrier by equal volume. The impregnation conditions are temperature 40℃ and impregnation time 6h. During the impregnation, the container is isolated from the outside by plastic film to prevent water evaporation;

[0145] (4) After drying the impregnated material, the precursor of the catalyst, i.e. the HY zeolite loaded with divalent nickel ions, is obtained.

[0146] The drying post-treatment temperature is 110℃ and the time is 12h. In this example, the preparation of the catalyst precursor (HY zeolite loaded with divalent nickel ions) requires three equal-volume impregnations, and after each equal-volume impregnation, the same drying treatment of the impregnated material is required before the next equal-volume impregnation. After the last equal-volume impregnation, the impregnated material is dried and sealed for use.

[0147] Second step: The precursor of the catalyst is treated with chemical plating to prepare a HY zeolite loaded with phosphatized nickel catalyst using sodium hypophosphite as the reducing agent. The chemical plating is carried out in an acidic plating solution, and the specific method is as follows:

[0148] (1) A buffer solution with a pH value of 4.7 is prepared with acetic acid and sodium acetate as buffer agents

[0149] According to the Handbook of Analytical Chemistry (Guo Weiqiang. Handbook of Analytical Chemistry Third Edition. Beijing: Chemical Industry Press, 2016.), 1 part (volume) of 0.1 mol / L acetic acid solution and 1 part of 0.1 mol / L sodium acetate solution are mixed to obtain a buffer solution with a pH value of 4.7.

[0150] (2) The precursor of the catalyst is treated with chemical plating in the pH buffer solution:

[0151] First, 150 ml of acetic acid-sodium acetate buffer solution was measured according to the requirements of the feeding amount of 5g catalyst precursor, the ratio of buffer solution to catalyst precursor (liquid-solid ratio) of 30 ml / g, and the phosphorus content of plating solution (phosphorus-nickel ratio, P to Ni molar ratio) of 10, and 16 g of sodium hypophosphite monohydrate reducing agent was added to prepare the plating solution, and the plating solution was heated to a chemical plating reaction temperature of 90°C under constant stirring.

[0152] Then, the measured catalyst precursor was slowly added to the chemical plating solution under constant stirring for phosphating treatment. After the catalyst precursor was fed, the chemical plating reaction was continued until no bubbles were generated in the plating solution, and the reaction was stopped. The residual solution of chemical plating was removed by filtration, the filter cake was washed with water to neutral (pH = 7), and then the filter cake after washing was dried for post-treatment (110°C, 12h) to obtain HY zeolite loaded nickel-phosphorus amorphous substance, i.e. the intermediate of the catalyst.

[0153] (3) Heat treatment of the catalyst intermediate to prepare HY zeolite loaded phosphorus nickel catalyst

[0154] The heat treatment was carried out in a H2 atmosphere. The heat treatment temperature was 400°C, the time was 2h, and the hydrogen flow rate (expressed by hydrogen volume space velocity, defined as the volume of hydrogen passing through the catalyst per unit time per unit volume, calculated as an ideal gas) was 600h -1 The obtained HY zeolite loaded phosphorus nickel catalyst was coded as Ni3P / HY-18-1 and stored in a sealed state for standby use.

[0155] The XRD characterization results (Figure 1) showed that the FAU type topological structure characteristic diffraction peak signal of the Ni3P / HY-18-1 catalyst was strong, and the relatively strong diffraction peaks at 2θ = 36.4°, 41.8°, 42.8°, 43.6°, 45.3°, 46.0°, 46.6°, 47.6°, 48.1° and 52.7° belonged to the main characteristic diffraction peaks of Ni3P crystal phase (PDF #65-1605), and the relatively weak characteristic diffraction peaks at 2θ = 44.6°, 51.9° and 76.8° belonged to the metal nickel crystal phase (PDF #01-1260). The NH3-TPD characterization results (Figure 2) showed that the acidity distribution of the Ni3P / HY-18-1 catalyst was obviously different from that of the HY zeolite carrier, the intensity of the low-temperature ammonia desorption peak (corresponding to the number of weak acid centers) near 200°C was weakened, the high-temperature desorption peak (corresponding to the number of strong acid centers) in the interval of 400-500°C basically disappeared, but a medium-temperature desorption peak (corresponding to the acid centers of medium intensity) appeared in the interval of 250-300°C. The specific surface area of the catalyst calculated by N2 physical adsorption experiment was 618m 2g. The above physicochemical property characterization results show that the prepared Ni3P / HY-18-1 catalyst is a HY zeolite supported metal-acid bifunctional catalyst mainly containing Ni3P crystal phase and a small amount of metal nickel crystal phase.

[0156] Step 3: Synthesis of cyclohexylbenzene by using HY zeolite supported nickel phosphide as catalyst for catalyzing benzene hydroalkylation reaction

[0157] Firstly, 3 g of Ni3P / HY-18-1 catalyst which was pressed into a tablet and sieved to 20-40 mesh was weighed and then loaded into the constant temperature section of the reactor (stainless steel reaction tube with an inner diameter of 16 mm). Porcelain balls were loaded on both sides of the catalyst bed, and quartz wool was used to separate the catalyst from the porcelain balls. After loading the catalyst, the sealing of the reactor was checked using N2, and then the pressure of the reactor was set to 1.8 MPa. The temperature of the reactor was raised to the reaction temperature of 180°C in flowing N2. After the temperature was stabilized, the reactant benzene was fed into the reactor using a metering pump. After the reactor effluent was stabilized, N2 was switched to H2, and the benzene hydroalkylation reaction was started. The benzene feed space velocity (WHSV) was kept at 0.88 h -1 -1, the benzene conversion rate of the Ni3P / HY-18-1 catalyst was 40.09%, the cyclohexylbenzene selectivity was 74.69%, the cyclohexane selectivity was 5.64%, the methylcyclopentane selectivity was 1.17%, the methylcyclopentylbenzene selectivity was 1.22%, the cyclohexylcyclohexane selectivity was 0.52%, the bicyclohexylbenzene selectivity was 15.44%, and the unidentified light components were 1.32%.

[0158] Comparative Example 1: This example is used to illustrate that the HY zeolite supported non-noble metal nickel catalyst prepared by the impregnation method is an effective catalyst for benzene hydroalkylation reaction. However, as a non-noble metal catalyst without phosphating treatment, its catalytic activity and selectivity in the benzene hydroalkylation reaction are low, and the amounts of methylcyclopentane and methylcyclopentylbenzene isomerization by-products generated are large.

[0159] Example 1 was repeated, but after the first step to obtain the precursor of the catalyst, i.e. the HY zeolite supported divalent nickel ions, the precursor of the catalyst was not subjected to phosphorization treatment, but was calcined in dry air at 500 °C for 2 h, and then subjected to reduction treatment with H2 at normal pressure, the reduction temperature being 500 °C and the reduction time being 3 h. The obtained catalyst was designated as Ni / HY-18-CE1 and was used in the benzene hydroalkylation reaction described in the third step. The benzene conversion over the Ni / HY-18-CE1 catalyst was 35.20%, the cyclohexylbenzene selectivity was 64.65%, the cyclohexane selectivity was 4.87%, the methylcyclopentane selectivity was 7.07%, the methylcyclopentylbenzene selectivity was 7.34%, the cyclohexylcyclohexane selectivity was 0.29%, the bicyclohexylbenzene selectivity was 13.30%, and the unclassified light components were 2.48%.

[0160] Comparative Example 2: This example is used to illustrate that the HY zeolite supported noble metal palladium catalyst prepared by impregnation method has excellent catalytic effect on benzene hydroalkylation reaction. However, the noble metal catalyst is expensive and the loading is limited. At the usual loading, its catalytic activity and selectivity for benzene hydroalkylation reaction, as well as the amount of isomerization by-products methylcyclopentane and methylcyclopentylbenzene are comparable to the HY zeolite supported phosphorized nickel catalyst provided by the present application.

[0161] The HY zeolite support was prepared according to the method of Example 1. On this basis, according to the method of the published document Mol. Catal., 2017, 442: 27-38, 0.2 wt.% of noble metal palladium was impregnated on the HY zeolite support to prepare the Pd / HY-0.2-CE2 catalyst. Specifically, 50 mg of palladium nitrate dihydrate was accurately weighed to prepare a 18 ml aqueous solution, and 10 g of the HY zeolite support was impregnated with the solution at room temperature, the impregnation time being 12 h. During the impregnation, the container was isolated from the outside by plastic film to prevent water evaporation. The impregnated zeolite was dried at 110 °C for 12 h. Then reduction was carried out in a H2 atmosphere, the reduction temperature being 400 °C and the reduction time being 4 h. The specific surface area of the catalyst was calculated to be 750 m 2 / g by N2 physical adsorption experiment. Finally, the Pd / HY-0.2-CE2 catalyst was subjected to benzene hydroalkylation reaction evaluation according to the method recorded in Example 1. The results showed that the benzene conversion over the Pd / HY-0.2-CE2 catalyst was 39.20%, the cyclohexylbenzene selectivity was 75.30%, the cyclohexane selectivity was 6.31%, the methylcyclopentane selectivity was 1.06%, the methylcyclopentylbenzene selectivity was 1.33%, the cyclohexylcyclohexane selectivity was 0.70%, the bicyclohexylbenzene selectivity was 14.10%, and the unclassified light components were 1.20%.

[0162] Example 2: This example is used to illustrate that when a zeolite-supported non-noble metal nickel is used as a precursor, sodium hypophosphite is used as a reducing agent, and a chemical plating method is used to phosphorize the catalyst precursor to prepare a zeolite-supported phosphorized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the hydroalkylation of benzene, the nickel loading of the precursor is allowed to be changed.

[0163] Example 1 is repeated, but when the catalyst precursor is prepared in the first step using the isochoric impregnation method, the divalent nickel ion loading in the precursor, calculated as metallic nickel, is changed to 3 wt.%, 6 wt.%, 9 wt.% (two loadings, 4.5 wt.% each), 12 wt.% (two loadings, 6 wt.% each), 15 wt.% (three loadings, 5 wt.% each), and 21 wt.% (three loadings, 7 wt.% each), respectively. The codes of the zeolite-supported phosphorized nickel catalysts prepared are Ni3P / HY-3-2, Ni3P / HY-6-2, Ni3P / HY-9-2, Ni3P / HY-12-2, Ni3P / HY-15-2, and Ni3P / HY-21-2, respectively; their specific surface areas are 734 m 2 / g, 708 m 2 / g, 670 m 2 / g, 656 m 2 / g, 646 m 2 / g, and 553 m 2 / g, respectively; in the benzene hydroalkylation reaction, the benzene conversion of the above catalysts is 14.55%, 22.66%, 32.59%, 38.365%, 39.22%, and 36.81%, respectively; and the cyclohexylbenzene selectivity is 81.25%, 76.99%, 74.98%, 73.97%, 73.86%, and 70.58%, respectively.

[0164] Example 3: This example is used to further illustrate that when a zeolite-supported non-noble metal nickel is used as a precursor, sodium hypophosphite is used as a reducing agent, and a chemical plating method is used to phosphorize the catalyst precursor to prepare a zeolite-supported phosphorized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the hydroalkylation of benzene, the nickel loading of the precursor is allowed to be changed.

[0165] Example 1 is repeated, but when the catalyst precursor is prepared in the first step using the isochoric impregnation method, the divalent nickel ion loading in the precursor, calculated as metallic nickel, is changed to 0.5 wt.%, 1 wt.%, and 2 wt.%, respectively. The codes of the zeolite-supported phosphorized nickel catalysts prepared are Ni3P / HY-0.5-3, Ni3P / HY-1-3, and Ni3P / HY-2-3, respectively; their specific surface areas are 785 m 2 / g, 773 m 2 / g, and 745 m 2The benzene conversion rates of the catalysts were 3.10%, 6.52% and 9.06%, respectively, and the cyclohexylbenzene selectivities were 86.81%, 85.23% and 83.44%, respectively, in the benzene hydroalkylation reaction.

[0166] Example 4: This example is used to further illustrate the preparation of a zeolite-supported phosphatized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation, in which the zeolite-supported non-noble metal nickel is used as the precursor, sodium hypophosphite is used as the reducing agent, and the chemical plating method is used to phosphatize the catalyst precursor, and the nickel loading of the precursor is allowed to be changed.

[0167] Example 1 is repeated, but in the first step, the catalyst precursor is prepared by the equal-volume impregnation method, and the divalent nickel ion loading in the precursor, calculated as metallic nickel, is changed to 25 wt.% (five loadings, 5 wt.% each time) and 30 wt.% (five loadings, 6 wt.% each time), respectively. The zeolite-supported phosphatized nickel catalysts thus prepared are denoted as Ni3P / HY-25-4 and Ni3P / HY-30-4, respectively, and their specific surface areas are 510 m 2 / g and 490 m 2 / g, respectively, and the benzene conversion rates of the catalysts were 32.24% and 24.10%, respectively, and the cyclohexylbenzene selectivities were 67.36% and 64.80%, respectively, in the benzene hydroalkylation reaction.

[0168] Example 5: This example is used to illustrate the preparation of a zeolite-supported phosphatized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation, in which the zeolite-supported non-noble metal nickel is used as the precursor, sodium hypophosphite is used as the reducing agent, and the chemical plating method is used to phosphatize the catalyst precursor, and the heat treatment conditions of the catalyst intermediate (the nickel-phosphorus amorphous substance supported by the HY zeolite) are allowed to be changed.

[0169] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the isovolume impregnation method, the loading of divalent nickel ions in the precursor was changed to 6 wt.% based on metallic nickel, and the catalyst intermediate (nickel-phosphorus amorphous material supported on HY zeolite) obtained by chemical plating and post-drying treatment was subjected to heat treatment in a H2atmosphere at temperatures of 200°C, 300°C, 400°C and 500°C, respectively. The benzene conversion rates of the catalyst intermediate (without heat treatment) and the zeolite-supported phosphorus nickel catalysts Ni3P / HY-6-200-5, Ni3P / HY-6-300-5, Ni3P / HY-6-400-5 and Ni3P / HY-6-500-5 prepared by heat treatment at the above different temperatures in the benzene hydroalkylation reaction were 3.38%, 9.98%, 15.38%, 23.23% and 21.07%, respectively; and the cyclohexylbenzene selectivities were 72.04%, 73.76%, 74.34%, 78.46% and 78.65%, respectively.

[0170] Example 6: This example is used to further illustrate that in the process of preparing a zeolite-supported phosphorus nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation using a non-noble metal nickel supported on HY zeolite as a precursor and sodium hypophosphite as a reducing agent, the heat treatment conditions of the catalyst intermediate (nickel-phosphorus amorphous material supported on HY zeolite) are allowed to be changed.

[0171] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the isovolume impregnation method, the loading of divalent nickel ions in the precursor was changed to 6 wt.% based on metallic nickel, and the catalyst intermediate (nickel-phosphorus amorphous material supported on HY zeolite) obtained by chemical plating and post-drying treatment was subjected to heat treatment in a H2atmosphere at temperatures of 200°C, 300°C, 400°C and 500°C, respectively. The benzene conversion rates of the catalyst intermediate (without heat treatment) and the zeolite-supported phosphorus nickel catalysts Ni3P / HY-6-200-5, Ni3P / HY-6-300-5, Ni3P / HY-6-400-5 and Ni3P / HY-6-500-5 prepared by heat treatment at the above different temperatures in the benzene hydroalkylation reaction were 3.38%, 9.98%, 15.38%, 23.23% and 21.07%, respectively; and the cyclohexylbenzene selectivities were 72.04%, 73.76%, 74.34%, 78.46% and 78.65%, respectively.

[0172] Example 7: This example is used to further illustrate that in the process of preparing a zeolite-supported phosphorus nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation using a non-noble metal nickel supported on HY zeolite as a precursor and sodium hypophosphite as a reducing agent, the heat treatment conditions of the catalyst intermediate (nickel-phosphorus amorphous material supported on HY zeolite) are allowed to be changed.

[0173] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the isovolume impregnation method, the loading of divalent nickel ions in the precursor was changed to 6 wt.%, and the temperature, time and H2 flow rate (expressed by the volume space velocity of hydrogen, defined as the volume of hydrogen passing through the catalyst per unit time per unit volume, calculated as an ideal gas) of the heat treatment of the catalyst intermediate (HY zeolite supported nickel-phosphorus amorphous substance) obtained by chemical plating and post-drying treatment in a H2 atmosphere were changed to 200°C-24h-2000h -1 , 600°C-0.5h-10h -1 (diluted with high-purity nitrogen gas) and 700°C-0.2h-5h -1 (diluted with high-purity nitrogen gas), respectively. The benzene conversion rates of the zeolite supported nickel phosphide catalysts Ni3P / HY-6-200-7, Ni3P / HY-6-600-7 and Ni3P / HY-6-700-7 prepared in the benzene hydroalkylation reaction were 25.28%, 24.53% and 27.04%, respectively; and the cyclohexylbenzene selectivities were 75.85%, 78.20% and 74.62%, respectively.

[0174] Example 8: This example is used to illustrate that in the process of preparing a zeolite supported nickel phosphide catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation, using a non-noble metal nickel supported on HY zeolite as the precursor and sodium hypophosphite as the reducing agent, the drying conditions after chemical plating are allowed to be changed to prepare the catalyst intermediate (HY zeolite supported nickel-phosphorus amorphous substance).

[0175] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the isovolume impregnation method, the loading of divalent nickel ions in the precursor was changed to 6 wt.%, and the drying conditions after chemical plating were changed to 110°C x 24h, 170°C x 6h, 200°C x 3h, 90°C x 72h, 80°C x 96h and 250°C x 1h, respectively. The catalyst intermediates (HY zeolite supported nickel-phosphorus amorphous substance) obtained were heat treated under the heat treatment conditions given in Example 1 in a H2 atmosphere to obtain the zeolite supported nickel phosphide catalysts Ni3P / HY-6-11024-8, Ni3P / HY-6-1706-8, Ni3P / HY-6-2003-8, Ni3P / HY-6-9072-8, Ni3P / HY-6-8096-8 and Ni3P / HY-6-2501-8. The benzene conversion rates in the benzene hydroalkylation reaction were all in the range of 22%-24%, and the cyclohexylbenzene selectivities were all in the range of 76-78%.

[0176] Example 9: This example is used to illustrate that when a non-noble metal nickel supported on HY zeolite is used as a precursor, sodium hypophosphite is used as a reducing agent, and a chemical plating method is used to phosphorize the catalyst precursor to prepare a phosphorized nickel supported on zeolite catalyst (Ni3P / HY) for synthesizing cyclohexylbenzene by benzene hydroalkylation, the phosphorus content of the chemical plating solution (i.e., the phosphorus to nickel molar ratio) is allowed to be changed.

[0177] Example 1 is repeated, but in the first step, the catalyst precursor is prepared using the equal volume impregnation method, the divalent nickel ion loading in the precursor is changed to 6 wt.%, and in the second step, the catalyst precursor is phosphorized using the chemical plating method, the phosphorus to nickel ratio of the chemical plating is changed to 6, 8, 10, 12, and 16 by changing the amount of sodium hypophosphite added to the plating solution. The benzene conversion rates of the prepared phosphorized nickel supported on zeolite catalysts Ni3P-6 / HY-6-9, Ni3P-8 / HY-6-9, Ni3P-10 / HY-6-9, Ni3P-12 / HY-6-9, and Ni3P-16 / HY-6-9 in the benzene hydroalkylation reaction are 22.45%, 24.24%, 27.14%, 23.23%, and 20.23%, respectively; and the cyclohexylbenzene selectivities are 75.06%, 77.82%, 79.04%, 79.33%, and 80.19%, respectively.

[0178] Example 10: This example is used to illustrate that when a non-noble metal nickel supported on HY zeolite is used as a precursor, sodium hypophosphite is used as a reducing agent, and a chemical plating method is used to phosphorize the catalyst precursor to prepare a phosphorized nickel supported on zeolite catalyst (Ni3P / HY) for synthesizing cyclohexylbenzene by benzene hydroalkylation, the conditions of the chemical plating are allowed to be changed.

[0179] Example 1 is repeated, but in the first step, the catalyst precursor is prepared using the equal volume impregnation method, the divalent nickel ion loading in the precursor is changed to 6 wt.%, and in the second step, the catalyst precursor is phosphorized using the chemical plating method, the conditions of the chemical plating are changed to liquid to solid ratio 5-temperature 60°C-phosphorus to nickel ratio 30, liquid to solid ratio 100-temperature 95°C-phosphorus to nickel ratio 2, and liquid to solid ratio 200-temperature 95°C-phosphorus to nickel ratio 6, respectively. The benzene conversion rates of the prepared phosphorized nickel supported on zeolite catalysts Ni3P-30 / HY-6-10, Ni3P-2 / HY-6-10, and Ni3P-6 / HY-6-10 in the benzene hydroalkylation reaction are 20.10%, 13.22%, and 16.78%, respectively; and the cyclohexylbenzene selectivities are 81.26%, 72.03%, and 75.60%, respectively.

[0180] Example 11: This example is used to further illustrate the preparation of a zeolite-supported phosphide nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the hydroalkylation of benzene using a non-noble metal nickel supported on HY zeolite as the precursor, sodium hypophosphite as the reducing agent, and a chemical plating method for phosphidizing the catalyst precursor, with the condition of the chemical plating allowed to be changed.

[0181] Example 1 was repeated, but in the first step, the catalyst precursor was prepared using the impregnation method in an equal volume, the loading of divalent nickel ions in the precursor was changed to 6 wt.%, and in the second step, the pH of the plating solution was changed to 4.5 and 5.0, respectively, when the catalyst precursor was phosphidized using the chemical plating method. Both of the plating solutions were prepared using an acetic acid-sodium acetate buffer solution. The preparation method of the buffer solution with pH = 4.5 was as follows: 32 g of sodium acetate trihydrate was dissolved in water, 134 ml of 6 mol / L acetic acid was added, and the solution was diluted to 500 ml. The preparation method of the buffer solution with pH = 5.0 was as follows: 50 g of sodium acetate trihydrate was dissolved in water, 34 ml of 6 mol / L acetic acid was added, and the solution was diluted to 500 ml. The zeolite-supported phosphide nickel catalysts Ni3P / HY-6-4.5-11 and Ni3P / HY-6-5.0-11 prepared in this way had benzene conversion rates of 23.12% and 22.90%, respectively, in the hydroalkylation of benzene, and cyclohexylbenzene selectivities of 76.34% and 77.35%, respectively.

[0182] Example 12: This example is used to further illustrate the preparation of a zeolite-supported phosphide nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the hydroalkylation of benzene using a non-noble metal nickel supported on HY zeolite as the precursor, sodium hypophosphite as the reducing agent, and a chemical plating method for phosphidizing the catalyst precursor, with the condition of the chemical plating allowed to be changed.

[0183] Example 1 was repeated, but in the first step, the equal-volume impregnation method was used to prepare the catalyst precursor, the divalent nickel ion loading in the precursor was changed to 6 wt.% based on metallic nickel, and in the second step, the chemical plating method was used to phosphorize the catalyst precursor, the pH value of the plating solution was changed to 3.8, 4.0, 5.6 and 6.0, respectively. The four plating solutions with different pH values were prepared using acetic acid-sodium acetate buffer solutions. The pH = 3.8 buffer solution was prepared by mixing 17.6 parts (by volume) of a 0.2 mol / L acetic acid solution and 2.4 parts of a 0.2 mol / L sodium acetate solution; the pH = 4.0 buffer solution was prepared by mixing 16.4 parts (by volume) of a 0.2 mol / L acetic acid solution and 3.6 parts of a 0.2 mol / L sodium acetate solution; the pH = 5.6 buffer solution was prepared by mixing 1 part (by volume) of a 0.1 mol / L acetic acid solution and 8 parts of a 0.1 mol / L sodium acetate solution; and the pH = 5.9 buffer solution was prepared by mixing 1 part (by volume) of a 0.1 mol / L acetic acid solution and 16 parts of a 0.1 mol / L sodium acetate solution. The benzene conversion rates of the zeolite-supported phosphorized nickel catalysts Ni3P / HY-6-3.8-12, Ni3P / HY-6-4.0-12, Ni3P / HY-6-5.6-12 and Ni3P / HY-6-5.9-12 in the benzene hydroalkylation reaction were 18.40%, 21.07%, 22.62% and 20.55%, respectively; and the cyclohexylbenzene selectivities were 73.16%, 76.39%, 75.05% and 71.44%, respectively.

[0184] Example 13: This example is used to illustrate that when a zeolite-supported non-noble metal nickel is used as the catalyst precursor, sodium hypophosphite is used as the reducing agent, and the chemical plating method is used to phosphorize the catalyst precursor to prepare a zeolite-supported phosphorized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation, various soluble nickel salts can be used as the nickel source for preparing the catalyst precursor.

[0185] Example 1 was repeated, but in the first step, the equal-volume impregnation method was used to prepare the catalyst precursor, and 1.7 mol / L divalent nickel ion impregnation solutions were prepared using nickel chloride hexahydrate, nickel nitrate hexahydrate and anhydrous nickel sulfate, respectively. Since the solubility of the above three nickel salts in water is high enough, the catalyst precursor with a divalent nickel ion loading of 18 wt.% based on metallic nickel does not need to be prepared by multiple equal-volume impregnations. The benzene conversion rates of the zeolite-supported phosphorized nickel catalysts Ni3P / HY-18-Cl-13, Ni3P / HY-18-N-13 and Ni3P / HY-18-S-13 in the benzene hydroalkylation reaction were 39.23%, 40.82% and 38.91%, respectively; and the cyclohexylbenzene selectivities were 73.89%, 74.20% and 75.53%, respectively.

[0186] Example 14: This example is to illustrate that when preparing a zeolite supported phosphidized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the hydroalkylation of benzene, the catalyst precursor is prepared by the impregnation of a HY zeolite support with a non-noble metal nickel supported on the HY zeolite as the precursor and sodium hypophosphite as the reducing agent, and the impregnated HY zeolite is allowed to be dried under different conditions to prepare the catalyst precursor.

[0187] Example 1 is repeated, but the loading of divalent nickel ions in the precursor is changed to 6 wt.% based on the metal nickel when the catalyst precursor is prepared by the isovolume impregnation method in the first step. Meanwhile, the isovolume impregnated HY zeolite is dried under the following conditions to prepare the catalyst precursor: 110°C x 24 h, 170°C x 6 h, 200°C x 3 h, 90°C x 72 h, 80°C x 96 h and 250°C x 1 h. The benzene conversion in the benzene hydroalkylation reaction over the prepared zeolite supported phosphidized nickel catalysts Ni3P / HY-6-11024-14, Ni3P / HY-6-1706-14, Ni3P / HY-6-2003-14, Ni3P / HY-6-9072-14, Ni3P / HY-6-8096-14 and Ni3P / HY-6-2501-14 is 21.90%, 22.35%, 22.60%, 23.05%, 22.78% and 22.81%, respectively; and the cyclohexylbenzene selectivity is 77.32%, 76.50%, 76.84%, 77.09%, 76.57% and 76.88%, respectively.

[0188] Example 15: This example is to illustrate that when preparing a zeolite supported phosphidized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the hydroalkylation of benzene, the catalyst precursor is prepared by the impregnation of a HY zeolite support with a non-noble metal nickel supported on the HY zeolite as the precursor and sodium hypophosphite as the reducing agent, and the impregnated HY zeolite is allowed to be dried under different conditions to prepare the catalyst precursor.

[0189] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the equal-volume impregnation method, and the loading of divalent nickel ions in the precursor, calculated as metallic nickel, was changed to 6 wt.%. Meanwhile, the HY zeolite support was subjected to equal-volume impregnation to prepare the catalyst precursor under the following conditions: (a) 25°C x 24 h; (b) 30°C x 12 h; (c) 80°C x 2 h; (d) 90°C x 1 h; and (e) 95°C x 0.5 h. In the a and b conditions, the container was isolated from the outside by a plastic film during the impregnation to prevent water evaporation; in the c, d and e conditions, the impregnation was carried out in a 5-fold excess of the impregnation solution (the concentration of nickel ions was about 0.57 mol / L) in a refluxing manner. After the impregnation, the excess impregnation solution was poured off, and the wet material was drained and dried. The benzene conversion in the benzene hydroalkylation reaction over the prepared zeolite-supported phosphatized nickel catalysts Ni3P / HY-6-25-15, Ni3P / HY-6-30-15, Ni3P / HY-6-80-15, Ni3P / HY-6-90-15 and Ni3P / HY-6-95-15 was 22.80%, 22.47%, 23.16%, 22.71% and 22.68%, respectively; and the cyclohexylbenzene selectivity was 76.33%, 76.59%, 77.40%, 77.29% and 77.23%, respectively.

[0190] Example 16: This example is used to illustrate that, in the preparation of a zeolite-supported phosphatized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the benzene hydroalkylation, using a non-noble metal nickel supported on a HY zeolite as the precursor and sodium hypophosphite as the reducing agent, the HY zeolite support is allowed to be prepared under different drying conditions.

[0191] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the equal-volume impregnation method, and the loading of divalent nickel ions in the precursor, calculated as metallic nickel, was changed to 6 wt.%. Meanwhile, in the preparation of the HY zeolite support by ammonium exchange, the intermediate and the final product of the ion exchange were subjected to drying treatment under the following conditions: (a) 130°C x 24 h, and (b) 170°C x 6 h. The benzene conversion in the benzene hydroalkylation reaction over the prepared zeolite-supported phosphatized nickel catalysts Ni3P / HY-6-130-16 and Ni3P / HY-6-170-16 was 23.20% and 23.15%, respectively; and the cyclohexylbenzene selectivity was 77.50% and 77.41%, respectively.

[0192] Example 17: This example is used to illustrate that, in the preparation of a zeolite-supported phosphatized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by the benzene hydroalkylation, using a non-noble metal nickel supported on a HY zeolite as the precursor and sodium hypophosphite as the reducing agent, the HY zeolite support is allowed to be prepared under different calcination conditions.

[0193] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the equal-volume impregnation method, and the loading of divalent nickel ions in the precursor, calculated as metallic nickel, was changed to 6 wt.%. Meanwhile, in the preparation of the HY zeolite carrier by ammonium exchange, the intermediate and the final product of ion exchange were subjected to calcination treatment under the following conditions, respectively: (a) 450°C x 12h x 1000h -1 (b) 550°C x 3h x 5000h -1 The benzene conversion rates of the prepared zeolite-supported phosphatized nickel catalysts Ni3P / HY-6-a-17 and Ni3P / HY-6-b-17 in the benzene hydroalkylation reaction were 22.05% and 22.91%, respectively; the cyclohexylbenzene selectivities were 76.33% and 76.75%, respectively.

[0194] Example 18: This example is used to illustrate that, in the preparation of a zeolite-supported phosphatized nickel catalyst (Ni3P / HY) for the synthesis of cyclohexylbenzene by benzene hydroalkylation, using a non-noble metal nickel supported on a HY zeolite as the precursor and sodium hypophosphite as the reducing agent, the HY zeolite carrier with different sodium contents can be used.

[0195] Example 1 was repeated, but in the first step, the catalyst precursor was prepared by the equal-volume impregnation method, and the loading of divalent nickel ions in the precursor, calculated as metallic nickel, was changed to 6 wt.%. Meanwhile, in the preparation of the HY zeolite carrier by ammonium exchange, the "two-exchange-one-calcination" and "three-exchange-two-calcination" ammonium exchange processes were used to prepare the HY zeolite, respectively. It was found by XRF determination that the sodium content of the HY zeolite (HY 21 ) prepared by the "two-exchange-one-calcination" ammonium exchange process was 3.60 wt.%, and the specific surface area was 790 m 2 / g; the sodium content of the HY zeolite (HY 32 ) prepared by the "three-exchange-two-calcination" ammonium exchange process was 1.57 wt.%, and the specific surface area was 795 m 2 / g. On this basis, the zeolite-supported phosphatized nickel catalysts Ni3P / HY 21 -6-18 and Ni3P / HY 32 -6-18 were prepared, and the benzene conversion rates in the benzene hydroalkylation reaction were 12.11% and 18.27%, respectively; the cyclohexylbenzene selectivities were 81.69% and 79.71%, respectively.

[0196] Example 19: This example is to illustrate that the HY zeolite supported non-noble metal nickel as precursor, sodium hypophosphite as reducing agent, and the phosphorization treatment of the catalyst precursor by electroless plating method, the preparation of zeolite supported phosphorization nickel catalyst (Ni3P / HY) for benzene hydroalkylation synthesis of cyclohexylbenzene, allows the use of different grain size of NaY zeolite to prepare HY zeolite carrier.

[0197] Example 1 was repeated, but the divalent nickel ion loading in the precursor was changed to 6 wt.% based on metallic nickel when the catalyst precursor was prepared by the equal volume impregnation method in the first step. At the same time, the commercially available NaY zeolite with a grain size of about 1 μm was used as the mother body for preparing the HY zeolite carrier, and the sodium content (as Na2O wt.%) was 13.01 wt.%, the SiO2 / Al2O3 molar ratio was 5.0, and the specific surface area was about 700 m2 / g. XRF determination showed that the sodium content of the HY zeolite carrier prepared by the "four exchange and three calcination" ammonium exchange process was 0.27 wt.%, and the specific surface area was 710 m2 / g. On this basis, the HY zeolite supported phosphorization nickel catalyst Ni3P / HY-6-19 prepared had a benzene conversion of 20.23% and a cyclohexylbenzene selectivity of 75.91% in the benzene hydroalkylation reaction. 2 2 Example 1 was repeated, but the divalent nickel ion loading in the precursor was changed to 6 wt.% based on metallic nickel when the catalyst precursor was prepared by the equal volume impregnation method in the first step. At the same time, the commercially available NaY zeolite with a grain size of about 1 μm was used as the mother body for preparing the HY zeolite carrier, and the sodium content (as Na2O wt.%) was 13.01 wt.%, the SiO2 / Al2O3 molar ratio was 5.0, and the specific surface area was about 700 m2 / g. XRF determination showed that the sodium content of the HY zeolite carrier prepared by the "four exchange and three calcination" ammonium exchange process was 0.27 wt.%, and the specific surface area was 710 m2 / g. On this basis, the HY zeolite supported phosphorization nickel catalyst Ni3P / HY-6-19 prepared had a benzene conversion of 20.23% and a cyclohexylbenzene selectivity of 75.91% in the benzene hydroalkylation reaction.

[0198] Example 20: This example is to illustrate that the HY zeolite supported non-noble metal nickel as precursor, sodium hypophosphite as reducing agent, and the phosphorization treatment of the catalyst precursor by electroless plating method, the preparation of zeolite supported phosphorization nickel catalyst (Ni3P / HY), can catalyze the benzene hydroalkylation reaction to synthesize cyclohexylbenzene under different reaction conditions.

[0199] Example 1 was repeated, but the divalent nickel ion loading in the precursor was changed to 6 wt.% based on metallic nickel when the catalyst precursor was prepared by the equal volume impregnation method in the first step. At the same time, the commercially available NaY zeolite with a grain size of about 1 μm was used as the mother body for preparing the HY zeolite carrier, and the sodium content (as Na2O wt.%) was 13.01 wt.%, the SiO2 / Al2O3 molar ratio was 5.0, and the specific surface area was about 700 m2 / g. XRF determination showed that the sodium content of the HY zeolite carrier prepared by the "four exchange and three calcination" ammonium exchange process was 0.27 wt.%, and the specific surface area was 710 m2 / g. On this basis, the HY zeolite supported phosphorization nickel catalyst Ni3P / HY-6-19 prepared had a benzene conversion of 20.23% and a cyclohexylbenzene selectivity of 75.91% in the benzene hydroalkylation reaction.

[0200] Example 21: This example is to further illustrate that the HY zeolite supported non-noble metal nickel as precursor, sodium hypophosphite as reducing agent, and the phosphorization treatment of the catalyst precursor by electroless plating method, the preparation of zeolite supported phosphorization nickel catalyst (Ni3P / HY), can catalyze the benzene hydroalkylation reaction to synthesize cyclohexylbenzene under different reaction conditions.

[0201] ​Example 1 was repeated, but the prepared Ni3P / HY-18-21 was used for the benzene hydroalkylation reaction at a reaction pressure of 1.5 MPa and 2.1 MPa, respectively. The benzene conversion and cyclohexylbenzene selectivity were 23.37% and 82.05%, respectively, when the reaction was carried out at 1.5 MPa; the benzene conversion and cyclohexylbenzene selectivity were 41.18% and 70.32%, respectively, when the reaction was carried out at 2.1 MPa.

[0202] Example 22: This example is used to further illustrate that the zeolite-supported phosphidized nickel catalyst (Ni3P / HY) prepared by using the non-noble metal nickel supported on HY zeolite as a precursor, sodium hypophosphite as a reducing agent, and a chemical plating method for phosphidizing the catalyst precursor can catalyze the benzene hydroalkylation reaction to synthesize cyclohexylbenzene under different reaction conditions.

[0203] Example 1 was repeated, but the prepared Ni3P / HY-18-22 was used for the benzene hydroalkylation reaction at a benzene feed space velocity of 0.66 h -1 and 1.32 h -1 , respectively. The benzene conversion and cyclohexylbenzene selectivity were 38.66% and 59.50%, respectively, when the benzene feed space velocity was 0.66 h -1 ; the benzene conversion and cyclohexylbenzene selectivity were 29.76% and 72.54%, respectively, when the benzene feed space velocity was 1.32 h -1 .

Claims

1. A method for preparing a HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene, characterized in that, The specific steps are as follows: Step 1: Prepare the catalyst precursor, namely divalent nickel ions supported on HY zeolite, using the equal-volume impregnation method. In the catalyst precursor, the weight percentage of divalent nickel ions, calculated as metallic nickel, ranges from 0.5 to 30 wt.%. The specific preparation steps of the catalyst precursor are as follows: (1) Using NaY zeolite as the parent material, HY zeolite support was prepared by ammonium exchange method; the sodium content of the prepared HY zeolite support, calculated as Na2O, was ≤3.8wt.%. (2) Preparation of impregnation solution for divalent nickel ions; First, the saturated water absorption rate of the calcined HY zeolite support is determined; then, based on the saturated water absorption rate of the zeolite support and the divalent nickel ion loading of the catalyst precursor to be prepared, the volume of impregnation solution and the concentration of divalent nickel ions required for the equal-volume impregnation method are calculated, wherein the divalent nickel ion loading is calculated as metallic nickel, and the nickel ion loading of the catalyst precursor is equal to the nickel content in the finished HY zeolite-supported nickel phosphide catalyst; on this basis, the required impregnation solution is prepared. If the required nickel ion concentration of the impregnation solution exceeds the maximum solubility of divalent nickel ions, then the single equal-volume impregnation needs to be changed to multiple equal-volume impregnations. The divalent nickel ions are provided using a water-soluble nickel salt; (3) Impregnate the HY zeolite carrier with an equal volume of the prepared divalent nickel ion impregnation solution; the impregnation conditions are: temperature 25℃-95℃, time 0.5h-24h. (4) The impregnated material is dried and then treated to obtain the precursor of the catalyst, namely divalent nickel ions supported on HY zeolite; The conditions for post-drying treatment are: temperature 80-250℃, time 1-96h; If the preparation of the catalyst precursor requires multiple equal-volume impregnations, the impregnated material must be dried after each equal-volume impregnation before the next equal-volume impregnation. Step 2: Using sodium hypophosphite as a reducing agent, the catalyst precursor is phosphated by chemical plating to prepare HY zeolite-supported nickel phosphide catalyst. The electroless plating is carried out in an acidic plating solution, and the specific procedure is as follows: (1) Select pH buffer solution In acidic plating solutions, the pH range of the plating solution is required to be 3.8-6.

0. Therefore, an acetate-sodium acetate buffer solution is selected as the pH buffer solution. (2) Phosphating of the catalyst precursor in a pH buffer solution using chemical plating: First, according to the ratio of the volume of the buffer solution to the amount of the catalyst precursor, i.e. the liquid-solid ratio, measure the acetic acid-sodium acetate buffer solution and heat it to the reaction temperature of the electroless plating while stirring continuously. Then, based on the amount of catalyst precursor fed and its nickel content, as well as the phosphorus content requirements of the electroless plating solution, the phosphorus-nickel ratio parameter of the electroless plating solution is determined. Then, according to the phosphorus-nickel ratio requirements of the electroless plating solution, sodium hypophosphite reducing agent is added to the buffer solution under continuous stirring to prepare the electroless plating solution. Next, the measured catalyst precursor is slowly added to the electroless plating solution under continuous stirring for phosphating treatment; after the catalyst precursor feeding is completed, the electroless plating reaction continues until no more bubbles are generated in the plating solution, at which point the reaction ends. After the electroless plating reaction is completed, the electroless plating residue is removed by filtration, the filter cake is washed with water until neutral, and then the washed filter cake is dried to obtain HY zeolite-supported nickel-phosphorus amorphous material, which is the intermediate of the catalyst. The ratio of the volume of the buffer solution to the amount of the catalyst precursor, i.e., the liquid-to-solid ratio, is 5-200 ml / g. The temperature range for electroless plating is 60℃-95℃; The phosphorus-nickel ratio (P to Ni molar ratio) of the electroless plating solution ranges from 2 to 30. The conditions for post-drying treatment are: temperature 80-250℃, time 1-96h; (3) Heat treatment of catalyst intermediates to prepare HY zeolite-supported nickel phosphide catalysts The heat treatment is carried out in an H2 atmosphere; the heat treatment temperature, time, and hydrogen volume hourly space velocity ranges are respectively... 200-700℃； 0.2-24h； 5-2000h -1 。 2. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene according to claim 1, characterized in that, In the first step, the catalyst precursor contains 1.0-25 wt.% divalent nickel ions (calculated as metallic nickel).

3. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene according to claim 2, characterized in that, In the first step, the catalyst precursor contains 1.5-20 wt.% divalent nickel ions (calculated as metallic nickel).

4. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene according to claim 1, characterized in that, In step (1), the sodium content of the prepared HY zeolite support, calculated as Na2O, is ≤2.0 wt.%.

5. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 4, characterized in that, In step (1), the sodium content of the prepared HY zeolite support, calculated as Na2O, is ≤0.5wt.%.

6. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene according to claim 1, characterized in that, In step (1), when preparing the HY zeolite support using the ammonium exchange method, the following heat treatment steps are adopted: first, a thorough drying pretreatment, followed by calcination in flowing dry air; wherein, the drying pretreatment conditions are within the range of temperature 110-170℃ and time 6-24h; the calcination conditions in flowing dry air are within the range of: Firing temperature: 450-550℃; Calcination time: 3-12 hours; Dry air flow rate is expressed as volumetric hourly space velocity: 1000-5000 h⁻¹ -1 ; After roasting, the intermediate products should be sealed and stored for later use to prevent moisture absorption.

7. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene according to claim 1, characterized in that, In step (2), the nickel salt that provides divalent nickel ions is one or more of nickel chloride, nickel nitrate, nickel sulfate, and nickel acetate.

8. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 1, characterized in that, In step (3), the immersion conditions range from 30℃ to 90℃, and the time is from 1h to 12h; In the first step (4), the conditions for post-drying treatment are a temperature of 90-200℃ and a time of 3-72h.

9. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 8, characterized in that, In step (3), the immersion conditions range from 40℃ to 80℃, and the time is from 2h to 6h; In the first step (4), the conditions for post-drying treatment are a temperature range of 110-170℃ and a time range of 6-24h.

10. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 1, characterized in that, In the second step (1), the pH range of the plating solution is 4.0 to 5.

6.

11. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 10, characterized in that, In the second step (1), the pH range of the plating solution is 4.5 to 5.

0.

12. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 1, characterized in that, In step (2), the volume of the buffer solution and the amount of catalyst precursor are calculated according to the liquid-solid ratio, and the range is 10-150 ml / g; The temperature range for electroless plating is 65-92℃. The phosphorus-nickel ratio (P to Ni molar ratio) of the electroless plating solution ranges from 6 to 16. The conditions for post-drying treatment are: temperature 90-200℃, time 3-72h.

13. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation reaction of benzene according to claim 12, characterized in that, In step (2), the volume of the buffer solution and the amount of catalyst precursor are calculated according to the liquid-solid ratio, and the range is 15-100 ml / g; The temperature range for electroless plating is 70-90℃. The phosphorus-nickel ratio (P to Ni molar ratio) of the electroless plating solution ranges from 6 to 16. The conditions for post-drying treatment are: temperature 110-170℃, time 6-24h.

14. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 1, characterized in that, In step (3), the heat treatment temperature, time, and hydrogen volume hourly space velocity range for the catalyst intermediate are respectively... 250-650℃； 0.5-20h； 10-1500h -1 。 15. The method for preparing the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene according to claim 14, characterized in that, In step (3), the heat treatment temperature, time, and hydrogen volume hourly space velocity range for the catalyst intermediate are respectively... 300-600℃； 1.5-15h； 100-1000h -1 。 16. The HY zeolite-supported nickel phosphide catalyst prepared by any of the methods described in claims 1-15 for the preparation of the HY zeolite-supported nickel phosphide catalyst for the hydrogenation alkylation of benzene is used as a catalyst to catalyze the hydrogenation alkylation of benzene to synthesize cyclohexylbenzene.

17. The application according to claim 16, characterized in that, The reaction conditions are as follows: reaction temperature 100-300℃, reaction pressure 0.5-5.0MPa, benzene feed space velocity 0.2-10h. -1 The molar ratio of hydrogen to benzene is 0.1-4.0.

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