Supported metal catalyst for selective hydrogenation reaction and preparation method thereof

Abstract

The invention relates to a supported metal catalyst for selective hydrogenation reaction and a preparation method and application thereof, the catalyst comprises a functional carrier, and a hydrogenation metal active component and an auxiliary metal which are supported on the functional carrier, and the catalyst is characterized in that the functional carrier is a high-silicon Y-type molecular sieve supported with Ag and Ce, the silica-alumina ratio of the high-silicon Y-type molecular sieve is 10-90, and the functional carrier is a high-silicon Y-type molecular sieve supported with Ag and Ce. The specific surface area is greater than or equal to 550m < 2 > / g; the hydrogenation metal active component loaded on the functional carrier comprises one or more of Pd, Pt, Au and Rh elements; the auxiliary metal comprises one or more metal elements selected from Co, Ni, Mo, W, Zn, La and Cu; the hydrogenation metal active component is at least dispersed on the surface of the high-silicon Y-type molecular sieve, and the particle size D50 of the loaded hydrogenation metal active component is 1-20nm.

Description

Technical Field

[0001] The present application relates to a catalyst for selective hydrogenation reaction, a preparation method thereof and an application thereof, and particularly relates to a metal-supported catalyst for selective hydrogenation reaction of diolefins in C5 components by-produced in coal chemical MTO, a preparation method thereof and an application thereof. Background Art

[0002] In recent years, with the successful application of coal-to-olefins technology and the rapid growth of the industrial scale, the production capacity of by-produced mixed C5 fractions has also increased accordingly. Due to different technical routes, there are obvious differences between the by-produced mixed C5 fractions in coal-to-olefins and the C5 fractions by-produced in traditional naphtha cracking and catalytic cracking: about 6% of C5 and above fractions are by-produced while producing ethylene and propylene by the MTO process, and the content of C5 components accounts for up to 45%; the content of high-value monoolefins in the by-produced mixed C5 fractions is relatively high (about 75%), and the content of diolefins is relatively low (4.86%). Therefore, under the background of the continuous change of the global petrochemical raw material supply form and the upgrading of the petrochemical industrial structure, the high-value comprehensive utilization of the by-produced mixed C5 fractions in coal-based methanol-to-olefins will gradually develop towards refinement, diversification and high-end chemicals.

[0003] The petrochemical industry has accumulated rich experience in light hydrocarbon processing, especially in the front stages of etherification, aromatization, isomerization, and saturated hydrogenation. Selective hydrogenation treatment of diolefins is carried out preferentially. The main factor is the presence of diolefins, especially conjugated diolefins, which have active chemical properties and are extremely prone to oligomerization reactions under acidic conditions, blocking the catalyst pores and causing rapid deactivation of the catalyst. At the same time, for polymer-grade olefin products, a small amount of diolefins mixed in have an initiator effect on the oxidation of olefins, resulting in a shorter induction period for olefin oxidation reactions. As a raw material for downstream fine chemical products, the diolefins contained in the mixed C5 fraction will also have an adverse impact on the catalysts and products of subsequent processes. Therefore, effective removal of diolefins is required before one-step processing. The existing selective hydrogenation technologies and catalysts for diolefins mainly focus on the industrial production of the petrochemical refining industry and fine chemicals, such as naphtha cracking (CN 102911714 A), pyrolysis gasoline hydrorefining (CN 115678596 A), selective hydrogenation of halogenated nitro compounds (J. Mol. Catal. A, 2009, 308: 79-86), etc. The core hydrogenation catalysts mainly include two types of catalysts represented by noble metal Pd-based and non-noble metal Ni-based catalysts. Palladium-based catalysts have advantages such as low starting temperature, high hydrogenation activity, high space velocity, long operation cycle, and strong regeneration ability (CN 115709076 A, CN 114950418 A, etc.). Nickel-based catalysts (CN 109438160 A, CN 115582129 A, etc.) have the characteristics of low price, good resistance to arsenic and sulfur poisoning, and good stability, but their hydrogenation activity is not ideal enough. Palladium and platinum-based catalysts have very high reaction activity, but when present in the form of single metals, they usually cause over-hydrogenation due to their high hydrogen dissociation ability. Usually, other promoter components need to be added to improve the selectivity for olefins. For example, modulating the catalytic performance by adding inert components to the active component to reduce the group sites of the active metal is the most common method currently.

[0004] US 6255548 B discloses a method for preparing a selective hydrogenation catalyst for unsaturated hydrocarbons such as alkynes and diolefins. The catalyst is prepared by loading at least one Group VIII metal and at least one promoter metal M on a support. The Group VIII metal can be one or several of nickel, palladium, platinum, rhodium, ruthenium, and iridium, preferably palladium, nickel, and platinum; the metal M is selected from one or several of germanium, tin, gold, and silver.

[0005] CN 111097445 A discloses a method for selective hydrogenation and alkyne removal of isoprene. The catalyst uses palladium as the active component, copper as the promoter, and alumina as the support. The catalyst prepared by this method shows excellent catalytic activity and selectivity in the selective hydrogenation and alkyne removal reaction of isoprene. The total remaining alkyne amount is 10 μg / g, and the loss rate of isoprene is 1.0%.

[0006] CN 102649063 A discloses a catalyst for the selective hydrogenation of phenylacetylene in the presence of styrene. The catalyst mainly uses metallic nickel or its oxide as the metal active component, lanthanum oxide and zinc oxide as its promoters, and a composite material of alumina and silica as the carrier, and is prepared by an impregnation method.

[0007] CN 102430406 B discloses a hydrogenation catalyst, characterized in that the active components are metallic palladium and rare earth oxides. The content of metallic palladium in the catalyst is 0.2 - 5 wt%, and the content of rare earth oxides is 0.1 - 2.5 wt%. This catalyst is prepared by formulating a palladium-rare earth aqueous solution with a water-soluble palladium-containing compound, a water-soluble rare earth-containing compound and water, and impregnating the carrier with the palladium-rare earth aqueous solution, and is used in the post-refining process of caprolactam hydrogenation.

[0008] In addition to rare earths being effective promoters for palladium metal, more and more studies have found in recent years that the combination of silver and palladium has obvious effects in the selective hydrogenation of dienes. For example, US 4484015 A provides a composition and method. The composition contains palladium and silver, and the amounts of palladium and silver are each sufficient to fully selectively hydrogenate a certain unsaturated hydrocarbon.

[0009] Regarding the problem of noble metal dispersion in selective hydrogenation catalysts, the development of new functional carriers and the introduction of dispersants have gradually become the focus of technological development.

[0010] CN 115582129 A discloses a nickel-based selective hydrogenation catalyst with both high activity and high olefin selectivity, its preparation method and its application in the reaction of selectively hydrogenating and converting a compound containing triple bonds into a double bond compound. The catalyst includes a functionalized carrier with hydrogenation activity and an active component supported on the functionalized carrier; the functionalized carrier is a reducible metal oxide or a solid solution formed by a reducible metal oxide; the reducible metal oxide is cerium oxide, vanadium oxide, titanium oxide, zirconium oxide, cobalt oxide, tin oxide or indium oxide, and has defective oxygen vacancies on the surface; the active component is Ni and a promoter.

[0011] CN 114950418 A discloses a catalyst for the effective selective hydrogenation of conjugated olefins. An active metal component is Pd and Pt, the carrier is an inorganic heat-resistant metal oxide (one or more of MgO, Al2O3, TiO2, CeO2, ZrO2 and MoO3), the active metal component is distributed in an eggshell type on the carrier and the active metal component is in a reduced state, and the shell layer thickness formed by the active metal component on the carrier is 5 - 50 μm.

[0012] CN 1175931 C reports a supported palladium-alumina catalyst for producing hydrogen peroxide by anthraquinone method and its preparation method, which involves a catalyst prepared by using Al2O3 pre-coated with a suitable amount of rare earth oxide and calcined at a high temperature of 900-1000°C as a carrier and impregnated with palladium content of 0.15%-0.25%.

[0013] It is not difficult to see from the development experience of the above-mentioned petrochemical selective hydrogenation catalysts that precious metals such as palladium and platinum do have an irreplaceable role in catalyst activity. How to improve the comprehensive performance of precious metal hydrogenation catalysts is focused on the following directions: (1) Develop a new functional carrier material suitable for palladium dispersion; (2) Reduce the cost of the precious metal content of the catalyst while maintaining catalytic activity; (3) Add additives and active component dispersants to improve the dispersion of precious metals. However, the catalysts designed by the prior art often sacrifice catalyst activity. There is a contradiction between activity and selectivity that is difficult to achieve at the same time, and there is a contradiction between the dispersion of active centers and the stability of carrier matching, etc. Therefore, how to effectively reduce the cost of hydrogenation reaction catalysts and develop selective hydrogenation catalysts with high activity, high selectivity and high stability is an urgent problem that needs to be solved. The research fields of existing catalyst development are mostly petrochemical and fine chemicals. With the development of MTO technology, its by-product mixed C5 fraction is the main raw material source for downstream fine chemical products. There is an urgent need to develop corresponding selective hydrogenation catalysts for deep processing of coal chemical C5 fraction with high catalytic activity, high diene selectivity, mild reaction temperature, rich carrier pore structure, nano-scale dispersion of active metals, not easy to deactivate, stable matching between hydrogenation metal active centers and functional carriers, and obvious synergistic catalytic effect. Summary of the invention

[0014] In view of the above technical problems, especially the lack of research in the field of industrial application of selective hydrogenation of diolefins in coal-to-olefin by-product components, the present invention provides a Pd-based selective hydrogenation catalyst with both high activity and high selectivity, which is a supported metal catalyst. The functional carrier used is a molecular sieve with rich pores, high silicon-aluminum ratio and loaded with Ag / CeO2. The dissociated hydrogen species can migrate between the functional carrier and the nanoscale Pd metal active component to produce synergistic catalysis (Science, 2012, 335, 1209-1212). The high specific surface area of ​​the carrier provides ample dispersion space for the active metal. The introduction of the auxiliary metal also helps the nanoscale dispersion of the precious metal Pd and the olefin selective catalytic performance, which can successfully convert the active diolefin components in the mixed gas that are easy to cause deactivation and coking into monoolefins.

[0015] To achieve one of the above objectives, the present invention provides a catalyst in which a hydrogenation active component metal is highly dispersed in the pores and on the surface of the Y-type molecular sieve, and at the same time provides a corresponding method for preparing the catalyst to further realize a Pd-based selective hydrogenation catalyst with both high activity and high diolefin selectivity.

[0016] In a second aspect, the present invention also provides a method for preparing a Pd-based selective hydrogenation catalyst with both high activity and high diolefin selectivity.

[0017] In a third aspect, the present invention also provides an application method of a Pd-based selective hydrogenation catalyst with both high activity and selectivity in the selective hydrogenation of diolefins in the by-products of coal-to-olefins.

[0018] The specific invention content is as follows:

[0019] Embodiment 1.

[0020] Embodiment 1. A supported metal catalyst for selective hydrogenation reaction, comprising: a functional support and a hydrogenation metal active component and a promoter metal supported thereon,

[0021] The functional support is a high-silica Y-type molecular sieve loaded with Ag and Ce, with a silica-alumina ratio of 10 to 90 and a specific surface area of greater than or equal to 550 m 2 / g;

[0022] The hydrogenation metal active component supported on the functional support includes one or more of Pd, Pt, Au, and Rh elements;

[0023] The promoter metal includes one or several metal elements selected from Co, Ni, Mo, W, Zn, La, and Cu; the hydrogenation metal active component is at least dispersed on the surface of the high-silica Y-type molecular sieve, and the particle size D50 of the supported hydrogenation metal active component is 1 to 20 nm.

[0024] Embodiment 2. The catalyst according to Embodiment 1, wherein the Ag is directly supported on the high-silica Y-type molecular sieve, and the hydrogenation metal active component is supported on the outer surface of the functional support;

[0025] The Ce-containing substance is CeO2, the content of Ag2O in the functional support is 0.1 to 2 wt%, and the content of CeO2 in the functional support is 0.5 to 4.5 wt%, calculated as the oxide of the supported metal; the content of the hydrogenation metal active component in the catalyst is 0.05 to 3 wt%, calculated as the supported metal; the atomic molar ratio of the promoter metal to the hydrogenation metal active component in the catalyst is (0.1 to 20):1.

[0026] Embodiment 3. The catalyst according to Embodiment 2, wherein the silica-alumina ratio of the functional support is at least one selected from the following: 10 - 90, 15 - 85, 20 - 75, 30 - 70.

[0027] Embodiment 4. The catalyst according to Embodiment 2, wherein the specific surface area of the functional support is greater than or equal to 600 - 700 m 2 / g.

[0028] Embodiment 5. The catalyst according to Embodiment 2, wherein the content of Ag2O in the functional support is at least one selected from the following: 0.1 - 1.8 wt%, 0.2 - 1.5 wt%, 0.4 - 1.0 wt%, based on the oxide of the supported metal; the content of CeO2 in the functional support is at least one selected from the following: 0.8 - 4.0 wt%, 1.0 - 3.8 wt%, 1.2 - 3.5 wt%, based on the metal oxide.

[0029] Embodiment 6. The catalyst according to Embodiment 2, wherein the content of the hydrogenation metal active component in the catalyst is at least one selected from the following: 0.05 - 2.5 wt%, 0.06 - 2.0 wt%, 0.08 - 1.5 wt%, 0.1 - 1.5 wt%, 0.4 - 1.5 wt%.

[0030] Embodiment 7. The catalyst according to Embodiment 2, wherein the particle size D50 of the hydrogenation metal active component is at least one selected from the following: 1 - 5 nm, 3 - 7 nm, 5 - 9 nm.

[0031] Embodiment 8. The catalyst according to Embodiment 2, wherein the proportion of the pore volume of the functional support in the total pore volume of the catalyst ≥ 60 vol%; the total pore volume is 0.35 - 0.55 cm 3 / g, the most probable distribution is 10 - 100 nm, and the pore volume refers to the pore volume with a pore diameter greater than or equal to 2 nm and less than or equal to 100 nm.

[0032] Embodiment 9. The catalyst according to Embodiment 2, wherein the atomic molar ratio of the promoter metal to the hydrogenation metal active component is at least one selected from the following: (0.1 - 20):1, (0.5 - 18):1, (2 - 10):1.

[0033] Embodiment 10. A method for preparing the catalyst according to any one of Embodiments 1 - 9, comprising the following steps:

[0034] (1) Select a high-silica Y-type molecular sieve Ⅰ with a silica-alumina ratio of 10 - 90 and perform ion exchange with a salt containing Ag ions, and obtain a Y-type molecular sieve Ⅱ containing Ag after low-temperature calcination;

[0035] (2) Mix the Y-type molecular sieve II obtained in step (1) with an aqueous solution containing a Ce salt, add an aqueous ammonia solution for precipitation, and then obtain the functional support I through filtration, drying, and calcination.

[0036] (3) Prepare an aqueous solution by mixing a compound containing a hydrogenation metal active component and a salt of a promoter metal, and slowly add a surfactant under stirring conditions to obtain an active metal salt solution with uniform metal dispersion.

[0037] (4) Slowly add the active metal salt solution prepared in step (3) to the suspension formed by slurrying the functional support I and water, stir evenly, adjust the pH of the mixed solution to alkaline by adding an alkaline pH regulator, filter, wash, dry, and calcine the obtained substance to obtain the catalyst.

[0038] Embodiment 11. According to the method described in Embodiment 10, in step (1), it further includes selecting a Y-type molecular sieve with a silica-alumina ratio of 5.5 or 5 - 190 and an acidic aqueous solution of an ammonium salt, and performing multiple ammonium exchange and multiple steam calcination processes to obtain a high-silica Y-type molecular sieve I; the ammonium salt includes one or more selected from ammonium chloride, ammonium sulfate, ammonium bicarbonate, ammonium nitrate, ammonium fluorosilicate, ammonium persulfate, and ammonium acetate.

[0039] Embodiment 12. According to the method described in Embodiment 11, in step (1), the multiple times are two times. In the two ammonium exchange processes, the mass ratio of the Y-type molecular sieve: ammonium salt: water is 1:(1 - 3):(5 - 20), the temperature is 50 - 100 °C, the pH regulator of the acidic solution is selected from one or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and citric acid, and the pH value control range is 1 - 6; in the two calcination processes, the treatment atmosphere is a nitrogen-oxygen mixed gas or water vapor, where the volume ratio of nitrogen to oxygen is 2.0 - 8.0, the calcination temperature is 400 - 800 °C, and the calcination time is 0.5 - 12 hours; in step (1), the salt of Ag ions is silver nitrate; the mass ratio of the high-silica Y-type molecular sieve I to water is 1:(5 - 20); the ion exchange temperature is 40 - 90 °C, and the exchange time is 0.5 - 12 hours; the low-temperature calcination temperature is 100 - 400 °C, the calcination time is 1 - 12 hours, and the calcination atmosphere is one of nitrogen and argon atmospheres; in the Ag-containing Y-type molecular sieve II, based on the dry basis of the high-silica Y-type molecular sieve I, the ratio of Ag2O is 1:(0.01 - 0.2).

[0040] Embodiment 13. According to the method described in Embodiment 10, in step (2), the Ce salt is one or a mixture of trivalent cerous oxalate nonahydrate, cerous nitrate hexahydrate, cerous carbonate dihydrate, cerium chloride hexahydrate / septahydrate; the concentration of the ammonia water is 25-28 wt%; the conditions are that the weight ratio of the Ag-containing molecular sieve based on dry basis weight, the Ce salt based on the weight of Ce2O3, and water is 1:(0.005-0.05):(5-10), the temperature is from room temperature to 95 °C, the time is 0.5-8 hours; the pH after precipitation with the ammonia water solution is 8-14; for the roasting, the treatment atmosphere is a nitrogen-oxygen mixed gas or water vapor, where the volume ratio of nitrogen to oxygen is (1-5):1; the roasting temperature is 350-800 °C; the roasting time is 0.5-12 hours.

[0041] Embodiment 14. According to the method described in Embodiment 10, in step (3), the compound containing the hydrogenation metal active component includes one or a mixture of palladium acetate, diamminedichloropalladium, palladium nitrate dihydrate, ammonium tetrachloropalladate, potassium tetrabromopalladate, dichlorobis(acetonitrile)palladium, palladium chloride, and palladium nitrate; the promoter metal includes one or a mixture of nitrate compounds, sulfate compounds, and chlorides of elements selected from Co, Ni, Mo, W, Zn, La, and Cu; the concentration of the aqueous solution of the compound containing the hydrogenation metal active component is 0.001-0.025 mol / L, and the molar ratio of the hydrogenation metal active component to the promoter metal atoms is selected to be 1:(0.1-30); the surfactant includes one or several of sulfonates of fatty acid methyl ester ethoxylates, dodecyl dimethyl betaine, coconut oil amide propyl hydroxysulfobetaine, lauryl amide propyl betaine, 2-dodecyl-N-hydroxyethyl-N-carboxymethyl imidazoline, and the concentration of the surfactant is 0.001-0.040 mol / L; the temperature for dropping and mixing the surfactant is 40-80 °C.

[0042] Embodiment 15. According to the method described in Embodiment 10, the functional carrier I is slurried with water, and the conditions are that the weight ratio of the functional carrier I based on dry basis weight and water is 1:(2-10), the stirring temperature is from room temperature to 100 °C, the time is 0.5-12 hours; the pH regulator is at least one of sodium hydroxide, potassium hydroxide, ammonia water, and urea; the pH value of the alkaline mixed solution is 9-14; the drying temperature is 100-150 °C, the drying time is 12-24 hours; the roasting temperature is 400-600 °C, the time is 4-12 hours; the roasting atmosphere is a nitrogen-oxygen mixed gas, and the volume ratio of nitrogen to oxygen is (1-5):1; the content of the hydrogenation metal active component is 0.1-2 wt%; the particle size of the hydrogenation metal active component is 1-5 nm.

[0043] Embodiment 16. A method for selective hydrogenation of olefins, which uses the catalyst described in any one of Embodiments 1-9 to catalyze the selective hydrogenation reaction of the olefins. The olefins include at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene, and branched cyclohexadiene.

[0044] Embodiment 17. The method according to Embodiment 16, which is used for selective hydrogenation of diolefins in the C5 fraction of the by-products of coal chemical MTO.

[0045] This application has at least one of the following beneficial effects: 1) With the rich pore structure provided by the high specific surface area molecular sieve support, the hydrogenation metal active component such as palladium is dispersed on the surface of the molecular sieve. Further, with the assistance of the Ce-containing substance and the promoter metal, finally the hydrogenation metal active component (Pd) is loaded to achieve the effect that Pd is dispersed in a good nanoscale state on the outer surface of the support, which is further beneficial to improving the high reaction activity of the catalyst and the high selectivity to diolefins; in this application, the "high-silica Y-type molecular sieve" refers to a Y-type molecular sieve with a silica-alumina ratio of 10 or higher.

[0046] 2) The functional support has a volume structure or pore structure with appropriate size and quantity. A further effect is that the pore structure is stable and evenly distributed, which provides the possibility for stable and efficient dispersion of nanoscale metal particles in the high specific surface area pores.

[0047] 3) A supported metal Pd-type catalyst provided by this solution uses a functional support that is a molecular sieve with rich pores, a high silica-alumina ratio, and loaded with Ag / CeO2. Dissociated hydrogen species can migrate between the support (containing Ag and Ce) and metal active components such as nanoscale Pd to produce synergistic catalysis. The high specific surface area support provides ample dispersion space for the active metal, and the introduction of the promoter metal also helps the high-content dispersion of noble metals such as Pd at the nanoscale and the olefin selective catalytic performance.

[0048] 4) By exchanging free Na ions in the pores of the molecular sieve with silver ions, the silver ions are combined into the molecular sieve or enter the sodalite cage structure of the Y-type molecular sieve. Further, the Na ions in the sodalite cage of the Y-type molecular sieve framework structure are replaced to balance the charge of the molecular sieve framework. While stabilizing the molecular sieve framework structure, an H spillover is formed between the noble metal loaded on the catalyst and the functional support, thereby achieving a hydrogenation enhancement effect.

[0049] Furthermore, the functional carrier prepared in this application is a high-silica Y zeolite loaded with Ag and CeO2. The introduction of Ag ions into the sodalite cages in the framework structure of the high-silica Y zeolite contributes to the high-temperature stability and charge balance of the zeolite framework, and forms an effective H migration "carrier" with CeO2 dispersed in the pores and deposited on the outer surface, helping the dissociated hydrogen species to migrate between the carrier and the nanoscale Pd metal active component and generating synergistic catalysis;

[0050] 5) The nanoscale dispersion of the metal active component Pd and the promoter metal of this application in the pores of the functional carrier. Further, the surfactant dispersion method combined with the metal precipitation of the alkaline regulator is used to obtain an atomic-level dispersion of the catalyst active component. The metal dispersion particle size is 1-5 nm, and the addition of the promoter metal effectively reduces the cost of the noble metal catalyst while maintaining a high catalytic activity; during the catalytic reaction process, the reactant conversion rate is high, the diffusion rate of the product is high, it is not easy to coke, and the catalytic selectivity of dienes is excellent;

[0051] 6) The catalyst provided in this application can be used for the efficient selective hydrogenation of by-products of coal-to-olefins, including the selective hydrogenation reaction of at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene and branched cyclohexadiene in the by-products of the coal-to-olefins reaction device. Among them, the selective hydrogenation effect of dienes in light olefins such as C5 olefin components is more obvious; Other features and advantages of this application will be described in detail in the subsequent specific implementation section. Compared with the existing catalysts, the catalyst described in this application has the advantages of high reaction activity, high diene selectivity, mild reaction temperature, rich carrier pore structure, less noble metal consumption, nanoscale dispersion of active metals, the catalyst is not easy to deactivate, the hydrogenation metal active center matches stably with the functional carrier, and the synergistic catalysis effect is obvious. The catalyst of this application has the characteristics of high reaction activity and high diolefin selectivity, and this selective hydrogenation catalyst.

[0052] In addition, the technical solution of the present invention also brings many other advantages, which will be described in detail in the specific implementation.

[0053] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention and do not limit the present invention.

[0055] Figure 1XRD pattern of high-silica Y zeolite Ⅰ in Example 2;

[0056] Figure 2 High-resolution scanning transmission electron microscopy (TEM) image of catalyst 4 in Example 4. Detailed implementation manners

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0058] The term "Y zeolite" in this application was first invented by Union Carbide Corporation in the United States in 1954. The International Zeolite Association has identified its topological structure and defined its code, and it has the meaning commonly understood by those skilled in the art. It is a type of synthetic zeolite with a framework structure type of FAU. The inner diameter of the supercage cavity in the Y zeolite framework structure is about 1.3 nm, and the pore diameter of its twelve-membered ring is 0.74 nm. It is precisely because the Y zeolite has a large cavity and a three-dimensional twelve-membered ring pore system that various organic molecules can enter the supercage and undergo catalytic reactions. It should be particularly noted that the silica-alumina ratio of the support zeolite involved in this application cannot exceed 200:1. A support zeolite with a silica-alumina ratio exceeding 200:1 cannot achieve the required aluminum content in this application and cannot achieve the required reaction. Applying the technical solution of a support zeolite with a silica-alumina ratio exceeding 200:1 to this application cannot achieve the invention objective of this application. The specific surface area of the high-silica Y zeolite is greater than or equal to 550 m 2 / g. Unless otherwise specified, the terms "loading" or "supporting" described in this application are the same technical terms with the same meaning and can be used interchangeably. When specific descriptions are made in this application, Pd is used as an example. Those skilled in the art should understand that similar effects can also be obtained by using noble metals Au, Pt, and Rh. Therefore, the solution of this application is applicable to one or a combination of Pd, Pt, Au, and Rh elements at the same time.

[0059] A preferred example of the catalyst implementation manner of the present invention is: the functional support is a high-silica Y zeolite supporting Ag and CeO2, with a silica-alumina ratio of 30 and a specific surface area of 600 m 2 / g; the content of Ag2O in the functional carrier is 1 wt%, and the content of CeO2 is 2 wt%, based on the metal oxide supported; the hydrogenation metal active component supported on the functional carrier is Pd, with a content of 1 wt%, based on the supported metal; the catalyst-supported promoter metal is Cu; the atomic molar ratio of the catalyst-supported promoter metal to Pd is 10:1;

[0060] The proportion of the mesopore volume of the Y-type molecular sieve in the carrier to the total pore volume is 60 vol%. The mesopore volume and the total pore volume of the molecular sieve are measured by the nitrogen adsorption BET specific surface area method. The mesopore volume refers to the pore volume with a pore diameter of 3 nanometers less than or equal to 100 nanometers;

[0061] On the high-silica Y-type molecular sieve, the Pd is supported on the outer surface of the molecular sieve; Ag enters the pores of the high-silica Y-type molecular sieve through ion exchange. The Pd is supported on the outer surface of the molecular sieve. The Pd is dispersed on the outer surface in a nanoscale form with the addition of the promoter metal and / or surfactant. The nanoscale is one or more of 1-5 nm, 3-7 nm, 5-9 nm, 1-20 nm. The nanoscale dispersion effect prepared in this preferred embodiment is similar to Figure 2 the shown effect.

[0062] The structural or layer sequence relationship of the Ag, Ce, and Pd supported on the molecular sieve in this application originates from the order of adding Ag, Ce, and Pd in the catalyst synthesis method of this application. The presence of the relevant Ag, Ce, and Pd was confirmed by detection on the substances generated after each preparation step. There is also the following scheme for the structure of Pd supported on the outer surface in this application: Ag is supported in the pores or the framework structure of the high-silica Y-type molecular sieve, on which cerium dioxide is dispersed, and the hydrogenation metal active components such as Pd and the promoter metal are dispersed on the surface of the cerium dioxide. This example is preferably prepared with reference to the synthesis method or control parameters of Example 9 of this application.

[0063] This example has at least one of the following effects: 1) The high specific surface area molecular sieve carrier provides a rich dispersion space for the metal. The synergistic effect of the Ag-containing and Ce-containing substances constructs a functional carrier. Finally, the supported hydrogenation metal active component (Pd) achieves an excellent effect of nanoscale dispersion of Pd in the pores and on the surface of the carrier under the action of the promoter metal, which is further beneficial to improving the high reaction activity of the catalyst and the high selectivity for diolefins;

[0064] 2) The functional carrier has a volume structure or pore structure with appropriate size and quantity. A further effect is that the pore structure is stable and evenly distributed, providing the possibility for the stable and efficient dispersion of nanoscale metal particles in the high specific surface area pores;

[0065] 3) A Pd-loaded metal catalyst provided by this solution uses a functional carrier, which is a molecular sieve with rich pores, a high silica-alumina ratio and loaded with Ag / CeO2. Dissociated hydrogen species can migrate between the carrier (containing Ag and Ce) and the nanoscale Pd metal active component to produce synergistic catalysis. The carrier with a high specific surface area provides ample dispersion space for the active metal, and the introduction of promoter metals also helps the high-content dispersion of noble metal Pd at the nanoscale and the selective catalytic performance for olefins.

[0066] 4) By exchanging free Na ions in the pores of the molecular sieve with silver ions, the silver ions are combined into the molecular sieve or enter the sodalite cage structure of the Y-type molecular sieve. Further, the Na ions in the sodalite cage of the Y-type molecular sieve framework structure are replaced to balance the charge of the molecular sieve framework. While stabilizing the molecular sieve framework structure, an H spillover is formed between the noble metal loaded on the catalyst and the functional carrier, thereby achieving a hydrogenation enhancement effect.

[0067] Furthermore, the functional carrier prepared in this application is a high-silica Y-type molecular sieve loaded with Ag and CeO2. The introduction of Ag ions into the sodalite cage in the framework structure of the high-silica Y-type zeolite helps the high-temperature stability and charge balance of the molecular sieve framework, and forms an effective H migration "carrier" with CeO2 deposited in the pores and on the outer surface, helping the dissociated hydrogen species to migrate between the carrier and the nanoscale Pd metal active component and produce synergistic catalysis.

[0068] 5) The nanoscale dispersion of the metal active component Pd and the promoter metal in the pores of the functional carrier. Further, the surfactant dispersion method is combined with the metal precipitation of the alkaline regulator to obtain an atomic-level dispersion of the catalyst active component. The metal dispersion particle size is 1-5 nm, and the addition of the promoter metal effectively reduces the cost of the noble metal catalyst while maintaining a high catalytic activity.

[0069] 6) The catalyst provided by this application can be used for the efficient selective hydrogenation of by-products in coal-to-olefins, including the selective hydrogenation reaction of at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene and branched cyclohexadiene in the by-products of the coal-to-olefins reaction device. Among them, the selective hydrogenation effect of diolefins in light olefin components such as C5 olefin components is more obvious. Other features and advantages of this application will be described in detail in the subsequent specific implementation section. Compared with the existing catalysts, the catalyst described in this application has the advantages of high reaction activity, high diolefin selectivity, mild reaction temperature, rich carrier pore structure, less noble metal consumption, nanoscale dispersion of active metals, the catalyst is not easily deactivated, the hydrogenation metal active center matches and stabilizes with the functional carrier, and the synergistic catalysis effect is obvious.

[0070] Another aspect of the present application provides a method for the selective hydrogenation of dienes, characterized by using the catalyst according to any one of the foregoing, for catalyzing the selective hydrogenation reaction of at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene and branched cyclohexadiene.

[0071] The production equipment used in the present application is the equipment commonly used in the art. For example, crystallization kettles and catalytic reactors are known in the prior art.

[0072] The specific implementation manner of the present application is mainly divided into two steps: First, prepare the target catalyst and characterize the performance of the catalyst, including crystallinity, silicon-aluminum ratio, the metal content supported on high-silica Y zeolite, the content of Pd metal supported on the functional carrier, the content of promoter metal, specific surface area, pore volume, metal particle size, etc.; Then, apply the synthesized catalyst to the selective catalytic reaction, and further evaluate the catalytic performance of the catalyst.

[0073] Among them, preparing the target catalyst is the core of the present application. The purpose of the present application is to prepare a high-yield catalyst with high reaction activity, high diene selectivity, mild reaction temperature, rich pore structure of the carrier, active metal nano-scale dispersion, the catalyst is not easily deactivated, the hydrogenation metal active center matches and stabilizes with the functional carrier, and the synergistic catalytic effect is obvious.

[0074] In order to prepare the target catalyst, the present application first prepares high-silica Y zeolite, and then performs Ag / CeO2 loading treatment on the high-silica Y zeolite. For example, first perform Ag ion exchange treatment on it, and then perform low-temperature calcination and Ce salt exchange deposition and calcination to prepare a functional carrier containing Ag / CeO2 type; Finally, for Pd and promoter metals, use the surfactant dispersion method combined with an alkaline regulator to deposit the active metals into the pores and on the surface of the functional carrier, obtaining a catalyst with atomic-level dispersion of active components. The present application prepares a variety of catalysts by changing the parameters in the treatment process.

[0075] After the catalyst is prepared, various physical and chemical indexes of the catalyst are characterized, mainly including:

[0076] The crystallinity of the present application is measured by the standard method of ASTM D5758-2001(2011)e1.

[0077] The n(SiO2) / n(Al2O3) of the present application, that is, the silicon-aluminum ratio, is calculated from the contents of silicon dioxide and aluminum oxide, and the contents of silicon dioxide and aluminum oxide are measured by the standard method of GB / T 30905-2014.

[0078] The content of the metal loaded on the catalyst of this application is determined by the standard method of GB / T 30905-2014.

[0079] The content of the noble metal active component of the catalyst of this application is determined by using the NexIon300Q inductively coupled plasma mass spectrometer (abbreviated as ICP) of PE Company, USA.

[0080] The specific surface area of this application is determined by the standard method of GB5816.

[0081] The pore volume of this application is determined by the standard method of GB5816.

[0082] The sodium content of this application is determined by the standard method of GB / T 30905-2014.

[0083] The metal particle size of this application is characterized by a high-resolution scanning transmission electron microscope.

[0084] After preparing the target catalyst, its catalytic performance is evaluated through a catalytic reaction.

[0085] The evaluation of the catalytic performance of the catalyst in this application is mainly achieved through conversion rate, yield and selectivity. For example, for the selective hydrogenation reaction of dienes:

[0086] Conversion rate = (mass of the target diene in the raw material - mass of the target diene in the product) ÷ (mass of the target diene in the raw material) * 100%

[0087] The selective hydrogenation of dienes in the C5 component by-product of coal-to-olefins is a main implementation method in the evaluation process of the catalytic performance of the catalyst in this application. The catalyst prepared in this application can also be used to catalyze at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene and branched cyclohexadiene. Therefore, this application also provides a method for the selective hydrogenation of olefins, using the catalyst described in this application to catalyze the selective hydrogenation reaction of the olefins, and the olefins include at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene and branched cyclohexadiene. The method is used for the selective hydrogenation of dienes in the C5 component of the by-product of coal chemical MTO.

[0088] Examples

[0089] The following will further illustrate this application through examples. However, this application is not limited thereby. The instruments and reagents used in the examples of this application are, unless otherwise specified, the instruments and reagents commonly used by those skilled in the art.

[0090] The Preparation and Characterization of the First Part of the Catalyst

[0091] Example 1

[0092] Catalyst 1 A synthesis method of a Pd / γ-Al2O3 catalyst, comprising the following steps:

[0093] Referring to the preparation method in Example 1 of CN 105771984 A: Take 10 g of a blank Al2O3 support, dry it at 120 °C for 4 h, raise the temperature programmatically to 450 °C and keep it at a constant temperature for roasting for 4 h. After the powder is cooled to room temperature, immerse it in 100 ml of a 1.0 mol / L citric acid solution, keep it at a constant temperature of 30 °C and let it stand for 12 h, then dry it at a constant temperature of 120 °C for 6 h, and roast it at 400 °C for 4 h; Immerse the obtained product in an aqueous solution of palladium chloride with a concentration of 0.059 mol / L in an equal volume, with an impregnation temperature of 50 °C and an impregnation time of 2 h, dry it at a constant temperature of 120 °C for 6 h, and roast it at 300 °C for 4 h to obtain the final product. The content of Pd in the catalyst is 0.5 wt%.

[0094] The metal loading on the Y-type molecular sieve in each successive step of the method in this example was determined by XPS and ICP (see Table 3 for details). The content of Pd in this example is 0.5 wt%, indicating that Pd is contained or loaded on the Y-type molecular sieve.

[0095] Example 2

[0096] Catalyst 2 A synthesis method of a Pd / high-silica Y catalyst, comprising the following steps:

[0097] Step 1 Dissolve 122.45 g of ammonium fluorosilicate (98 wt%) in 1200 g of deionized water, add 100 g of the original powder of NaY molecular sieve with n(SiO2) / n(Al2O3) = 5.5 (Dalian Haixin Chemical Co., Ltd.), stir evenly, and then drop 0.5 mol / L hydrochloric acid until the pH value of the solution is 3. Raise the temperature to 80 °C and stir at a constant temperature for 4 h. After the product is filtered, washed with water, and dried, carry out a slightly positive pressure hydrothermal roasting treatment in an atmosphere of 650 °C, 100% water vapor, and 0.05 MPa for 8 h; After the obtained product is cooled to room temperature, repeat the above steps to carry out one more ammonium exchange and one more steam roasting process to obtain high-silica Y-type molecular sieve I, and the n(SiO2) / n(Al2O3) of the molecular sieve is 60.

[0098] Step 2: Weigh 0.084 g of PdCl2 (99 wt%) and dissolve it in 25 g of deionized water, denoted as solution A. Weigh 10 g of the prepared high-silica Y zeolite I and add it to 60 g of deionized water, stir to form a suspension, then slowly add solution A, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 12 by adding sodium hydroxide. The obtained product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h under a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd / high-silica Y catalyst, and the content of Pd in the catalyst is 0.5 wt%.

[0099] The metal loading on the Y zeolite in each step of the method in this example was determined by XPS and ICP (see Table 3 for details). The content of Pd in this example is 0.5 wt%, indicating that Pd is contained or loaded on the Y zeolite. At the same time, according to Figure 1 the X-ray diffraction pattern, it can be seen that the high-silica Y zeolite I was obtained by the preparation method of this example. (The X-ray diffraction patterns of the related zeolites or catalysts expressed as "high-silica" in other examples are similar to this example and all belong to the high-silica Y zeolite, so they will not be listed repeatedly here).

[0100] Example 3

[0101] Catalyst 3 A synthesis method of a Pd / high-silica Y-Ag catalyst, comprising the following steps:

[0102] Step 1: Dissolve 0.59 g of Ag(NO)3 (99.8 wt%) in 150 g of deionized water, then add 10 g of the high-silica Y zeolite I synthesized in Example 2 (n(SiO2) / n(Al2O3) = 60), stir evenly, heat up to 80 °C, and perform ion exchange for 2 h. After the product is filtered, washed with water, and dried, it is transferred to a muffle furnace and calcined at 300 °C for 4 h under a nitrogen atmosphere to obtain a high-silica Y zeolite containing Ag.

[0103] After the high-silica Y zeolite was obtained in the first step, the content of Ag in the high-silica Y zeolite calculated as Ag2O was 3.76 wt% by XPS test, indicating that at least Ag was loaded on the zeolite or its pores in this method step. For specific results, see Table 3.

[0104] Step 2: Weigh 10 g of the molecular sieve prepared above, and load Pd metal by referring to the method in Step 2 of Example 2 to obtain a Pd / high-silica Y-Ag catalyst. After the high-silica Y-type molecular sieve loaded with Ag passes through the second step, the content of Pd on the high-silica Y-type molecular sieve is measured by ICP to be 0.5 wt%, and the results are shown in Table 3 in detail, that is, the content of Pd in the catalyst is 0.5 wt%. In other examples of this application, during the preparation of the Y-type molecular sieve or the catalyst, after each addition of any substance containing "Ag", "Ce", "metal promoter", "Pd", etc. and reaction, the above method is used for testing to confirm whether each of the substances added in sequence is loaded in sequence.

[0105] This example has at least one of the following beneficial effects

[0106] In this method, free Na ions in the pores of the molecular sieve are exchanged by silver ions, so that the silver ions are combined into the molecular sieve or enter the sodalite cage structure of the Y-type molecular sieve. Further, the Na ions in the sodalite cage of the Y-type molecular sieve framework structure are replaced to balance the charge of the molecular sieve framework. While stabilizing the molecular sieve framework structure, H spillover is formed between the noble metal loaded on the catalyst and the functional support, thereby achieving a hydrogenation enhancement effect.

[0107] The catalyst provided by this application can be used for the efficient selective hydrogenation of by-products in coal-to-olefins, including the selective hydrogenation reaction of at least one selected from 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, branched cyclopentadiene, cyclohexadiene and branched cyclohexadiene in the by-products of the coal-to-olefins reaction device. Among them, the selective hydrogenation effect of diolefins in light olefins such as C5 olefin components is more obvious; other features and advantages of this application will be described in detail in the subsequent specific implementation part. Compared with the existing catalysts, the catalyst described in this application has the advantages of high reaction activity, high diolefin selectivity, mild reaction temperature, rich carrier pore structure, nano-scale dispersion of active metals, the catalyst is not easily deactivated, the hydrogenation metal active center and the functional support are matched and stable, and the synergistic catalytic effect is obvious, etc.

[0108] Other examples of this application, such as the examples of catalysts 4, 6, 7, 8, 9, 10, 11, 12, and 13, also have at least the above effects.

[0109] Example 4

[0110] Synthesis method of a Pd / high-silica Y-Ag-CeO2 catalyst for catalyst 4, including the following steps:

[0111] Step 1: Dissolve 0.86 g of CeCl3·6H2O (99.99 wt%) in 80 g of deionized water, then add 10 g of the Ag-containing high-silica Y zeolite synthesized in Example 3. After stirring at 80 °C for 4 h, slowly add 26 wt% ammonia water to adjust the pH value of the solution to 13. The product is filtered, washed with water, dried, and then transferred to a muffle furnace for calcination at 600 °C for 4 h in a water vapor atmosphere. The product is denoted as functional support I. After passing the Ag-containing high-silica Y zeolite through the first step, XPS test is selected. The content of Ce on the zeolite, calculated as CeO2, is 3.75 wt%. This indicates that at least Ce or its oxide is loaded on the Ag-containing high-silica Y zeolite in this preparation method step. For specific results, see Table 3.

[0112] Step 2: Weigh 10 g of the above-prepared functional support I, and load Pd metal by referring to the method in Step 2 of Example 2 to obtain a Pd / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.5 wt%.

[0113] The Pd / high-silica Y-Ag-CeO2 catalyst obtained in Step 2 is tested by electron microscopy to obtain an electron micrograph as Figure 2 shown. It can be clearly seen that Pd is well and relatively uniformly dispersed in the form of nanoscale on the Y zeolite in the figure. The Ag-containing and Ce-containing high-silica Y zeolites or catalysts prepared in other embodiments of the present application also at least have the effect of good nanoscale dispersion of Pd shown in the electron micrograph of this example, and will not be repeated specifically.

[0114] In addition, it should be noted that when testing promoter metals such as Ag, Ce, Cu, and Pd in each preparation process of other embodiments, the corresponding test results are shown in Table 2, and will not be elaborated for each specific embodiment.

[0115] In addition to the effects of Example 3, this example also has at least one of the following beneficial effects. First, the high-silica Y zeolite is prepared by a two-exchange and two-calcination method, and the high-silica Y-Ag-CeO2 type high-silica functional support is prepared by Ag ion exchange and exchange precipitation of trivalent Ce salt. Then, the Pd metal and promoter metals are uniformly mixed by the surfactant method, and then the active metal and promoter metals are uniformly deposited and dispersed in the form of nanoparticles inside the pores of the functional support through methods such as alkaline regulators and calcination, providing sufficient single-atom active centers and reaction active spaces for the selective catalysis of diolefins;

[0116] The nano-scale dispersion of the metal active component Pd and promoter metals of the present application in the pores of the functional support. Further, the surfactant dispersion method combined with the metal precipitation of the alkaline regulator is used to obtain atomic-level dispersion of the catalyst active components. The metal dispersion particle size is 1-5 nm, and the addition of promoter metals effectively reduces the cost of noble metal catalysts while maintaining high catalytic activity.

[0117] Example 5

[0118] Catalyst 5 A method for synthesizing a Pd / low-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0119] Step 1 Dissolve 0.59 g of AgNO3 (99.8 wt%) in 150 g of deionized water, then add 10 g of NaY molecular sieve raw powder with n(SiO2) / n(Al2O3) of 5.5 (Dalian Haixin Chemical Co., Ltd.). After stirring evenly, heat up to 80 °C and carry out ion exchange for 2 h. After the product is filtered, washed with water and dried, transfer it to a muffle furnace and calcine it at 300 °C for 4 h under a nitrogen atmosphere to obtain a Ag-containing low-silica Y-type molecular sieve.

[0120] Step 2 Dissolve 0.86 g of CeCl3·6H2O (99.99 wt%) in 80 g of deionized water, then add 10 g of the Ag-containing low-silica Y-type molecular sieve prepared in Step 1. After stirring at 80 °C for 4 h, slowly dropwise add 26 wt% ammonia water to adjust the pH value of the solution to 13. After the product is filtered, washed with water and dried, transfer it to a muffle furnace and calcine it at 600 °C for 4 h under a water vapor atmosphere. The product is denoted as functional support II.

[0121] Step 3 Weigh 10 g of the above-prepared functional support II, and load Pd metal by referring to the method in Step 2 of Example 2 to obtain a Pd / low-silica Y-Ag-Ce catalyst, and the content of Pd in the catalyst is 0.5 wt%.

[0122] In this example, the low-silica molecular sieve preparation catalyst has poor catalytic effect stability and durability. Therefore, the low-silica catalyst described in this example has unstable durability, which affects the overall production and use efficiency of the catalyst.

[0123] Example 6

[0124] Catalyst 6 A method for synthesizing a Pd-Co / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0125] Step 1 Weigh 0.084 g of PdCl2 (99 wt%) and 0.138 g of Co(NO3)2·6H2O and dissolve them in 25 g of deionized water. At 40 °C, while stirring, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as solution B.

[0126] Step 2: Weigh 10 g of the functional carrier I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution B, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h under a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd-Co / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.5 wt%, and the content of Co is 0.28 wt%.

[0127] As shown in the evaluation data in Table 2, the presence of promoter metals such as Co, Ni, Mo, W, Zn, La, Cu and / or surfactants such as fatty acid methyl ester ethoxylate sulfonate in the examples of this application in the above reaction is at least beneficial to the dispersion of palladium or the long-term stable improvement of the 1,3-pentadiene conversion rate. Similar effects will also occur in other examples where the above promoters or surfactants are involved, and will not be elaborated for each example.

[0128] Example 7

[0129] A method for synthesizing a Pd-Ni / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0130] Step 1: Weigh 0.084 g of PdCl2 (99 wt%) and 0.139 g of Ni(NO3)2·6H2O (98 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of a fatty acid methyl ester ethoxylate sulfonate aqueous solution (0.01 mol / L), denoted as Solution C.

[0131] Step 2: Weigh 10 g of the functional carrier I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution C, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h under a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd-Ni / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.5 wt%, and the content of Ni is 0.28 wt%.

[0132] Example 8

[0133] A method for synthesizing a Pd-Zn / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0134] Step 1: Weigh 0.084 g of PdCl2 (99 wt%) and 0.127 g of Zn(NO3)2·6H2O (99 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as Solution D.

[0135] Step 2: Weigh 10 g of the functional support I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution D, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h in a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd-Zn / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.5 wt%, and the content of Zn is 0.28 wt%.

[0136] Example 9

[0137] A method for synthesizing a Pd-Cu / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0138] Step 1: Weigh 0.084 g of PdCl2 (99 wt%) and 0.108 g of Cu(NO3)2·6H2O (99.9 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as Solution E.

[0139] Step 2: Weigh 10 g of the functional support I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution E, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h in a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd-Cu / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.5 wt%, and the content of Cu is 0.28 wt%.

[0140] Example 10

[0141] A method for synthesizing a Pd-Cu / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0142] Step 1: Weigh 0.0084 g of PdCl2 (99 wt%) and 0.108 g of Cu(NO3)2·6H2O (99.9 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as Solution F.

[0143] Step 2: Weigh 10 g of the functional carrier I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution F, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h in a mixed gas of nitrogen and oxygen (the volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd-Cu / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.05 wt%, and the content of Cu is 0.28 wt%.

[0144] Example 11

[0145] A method for synthesizing a Pd-Cu / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0146] Step 1: Weigh 0.0168 g of PdCl2 (99 wt%) and 0.108 g of Cu(NO3)2·6H2O (99.9 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as Solution G.

[0147] Step 2: Weigh 10 g of the functional carrier I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution G, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h in a mixed gas of nitrogen and oxygen (the volume ratio of nitrogen to oxygen is 3.5:1) to obtain a Pd-Cu / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.1 wt%, and the content of Cu is 0.28 wt%.

[0148] Example 12

[0149] A method for synthesizing a Pd-Cu / high-silica Y-Ag-CeO2 catalyst, comprising the following steps:

[0150] Step 1: Weigh 0.0337 g of PdCl2 (99 wt%) and 0.108 g of Cu(NO3)2·6H2O (99.9 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as Solution H.

[0151] Step 2: Weigh 10 g of the functional support I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution H, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h under a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain the Pd-Cu / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 0.2 wt%, and the content of Cu is 0.28 wt%.

[0152] Example 13

[0153] A method for synthesizing a Pd-Cu / high-silica Y-Ag-CeO2 catalyst includes the following steps:

[0154] Step 1: Weigh 0.168 g of PdCl2 (99 wt%) and 0.108 g of Cu(NO3)2·6H2O (99.9 wt%), dissolve them in 25 g of deionized water, and while stirring at 40 °C, dropwise add 10 ml of an aqueous solution of fatty acid methyl ester ethoxylate sulfonate (0.01 mol / L), denoted as Solution J.

[0155] Step 2: Weigh 10 g of the functional support I prepared in Example 4, add it to 60 g of deionized water, stir to form a suspension, then slowly add Solution J, stir at 40 °C for 4 h, and adjust the pH of the mixed solution to 13 by adding ammonia water. The product is filtered, washed, dried at 120 °C for 20 h, and then calcined at 500 °C for 8 h under a mixed gas of nitrogen and oxygen (volume ratio of nitrogen to oxygen is 3.5:1) to obtain the Pd-Cu / high-silica Y-Ag-CeO2 catalyst. The content of Pd in the catalyst is 1 wt%, and the content of Cu is 0.28 wt%.

[0156] The second part: Catalyst reaction performance evaluation

[0157] Reduce the catalyst prepared in the example. The reduction pressure is 1.5 MPa, the hydrogen flow rate is 20 mL / min, the temperature is 30 °C, and the reduction time is 4 h to obtain the activated hydrogenation catalyst; for the activated catalyst, the reaction performance evaluation conditions are a temperature of 40 °C, a raw material liquid volume space velocity of 1.5 h -1 , a pressure of 1.55 MPa, and a hydrogen-oil ratio of 25.

[0158] Table 1 shows the analysis results of the composition after removing heavy components of the by-product C5 fraction from a certain MTO plant. Based on the results in Table 1, simulate the composition of the catalytic evaluation raw material 1, in which the content of isoprene in 1,3-pentadiene is 4.70 wt%, and the content of isoprene is 95.3 wt%. The test results of the selective hydrogenation reaction performance of the catalysts prepared in Examples 1 to 14 are shown in Table 2 below.

[0159] Table 1 Composition of C5 fraction by - product after heavy - component removal in a certain MTO plant

[0160]

[0161] Table 2 Evaluation data of selective hydrogenation reaction of feedstock composition 1

[0162]

[0163] It can be seen from the results in Table 2 that, compared with the catalyst with alumina support, the catalysts 4, 6, 7, 8, 9, 10, 11, 12, 13 with high - silica Y functional support containing Ag and CeO2 have higher ability to catalytically convert 1,3 - pentadiene and less isoprene loss (dissociated hydrogen species can migrate between the functional support and the nano - sized Pd metal active component to produce synergistic catalysis, and the support with high specific surface area provides abundant dispersion space for the active metal). The above diolefin conversion data further confirm the beneficial effect of the nano - sized dispersion of palladium in the support of the present application scheme on the selective hydrogenation reaction, and also confirm the high efficiency and rapidity of the preparation method of the present application; compared with the catalyst 5 with low - silica Y functional support, the high - silica support has weaker acidity, more uniform dispersion of the active metal, is not easily deactivated during the reaction process, and has a longer catalyst life; the introduction of different promoter metals has different effects on the nano - sized dispersion of Pd, and the synergistic catalysis of the introduction of Cu and Pd is more excellent; the introduction of an appropriate amount of Pd is helpful for the selective hydrogenation of diolefins, and the introduction of excessive Pd will increase the loss of monoolefins.

[0164] Table 3 Test data of metal loading after relevant reaction steps in the examples

[0165]

[0166] It can be known from the results in Table 3 that it further confirms that Pd is loaded onto the Y - type molecular sieve as described in the examples in the table, and it also further confirms the loading of silver on the support of the molecular sieve as described in Examples 3, 4, and 9; meanwhile, in Example 4, after loading silver on the molecular sieve, the substance containing cerium (CeO2) is loaded, and finally the hydrogenation metal active component such as "Pd" is loaded on the outer surface of the molecular sieve; in addition, other examples such as 6, 7, 8, 9, 10, 11, 12, 13 are also loaded at least according to the steps of Example 4 and have similar test results to Example 4.

[0167] The above - mentioned specifically illustrates and describes the exemplary embodiments of the present disclosure. It should be understood that the present disclosure is not limited to the detailed structures, setting methods or implementation methods described here; on the contrary, the present disclosure intends to cover various modifications and equivalent settings included within the spirit and scope of the appended claims.

Claims

1. A supported metal catalyst for selective hydrogenation reaction, comprising: A functional carrier, a hydrogenation metal active component and a promoter metal supported thereon, characterized in that: The functional carrier is a high-silica Y-type molecular sieve loaded with Ag and Ce, with a silica-alumina ratio of 10 to 90 and a specific surface area of greater than or equal to 550 m 2 / g; The hydrogenation metal active component supported on the functional carrier includes one or more of the elements Pd, Pt, Au, and Rh; The promoter metal includes one or several metal elements selected from Co, Ni, Mo, W, Zn, La, and Cu; the hydrogenation metal active component is at least dispersed on the surface of the high-silica Y-type zeolite, and the particle size D50 of the supported hydrogenation metal active component is 1 to 20 nm.

2. The catalyst according to claim 1, characterized in that: The Ag is directly supported on the high-silica Y-type zeolite, and the hydrogenation metal active component is supported on the outer surface of the functional carrier; The Ce-containing substance is CeO2, the content of Ag2O in the functional carrier is 0.1 to 2 wt%, and the content of CeO2 in the functional carrier is 0.5 to 4.5 wt%, calculated as the oxide of the supported metal; the content of the hydrogenation metal active component in the catalyst is 0.05 to 3 wt%, calculated as the supported metal; the atomic molar ratio of the promoter metal to the hydrogenation metal active component in the catalyst is (0.1 to 20):

1.

3. The catalyst according to claim 2, characterized in that, The silica-alumina ratio of the functional carrier is at least one selected from the following: 10 to 90, 15 to 85, 20 to 75, 30 to 70.

4. The catalyst according to claim 2, wherein The specific surface area of the functional carrier is greater than or equal to 600-700 m 2 / g.

5. The catalyst according to claim 2, characterized in that, The content of Ag2O in the functional carrier is at least one selected from the following: 0.1 to 1.8 wt%, 0.2 to 1.5 wt%, 0.4 to 1.0 wt%, calculated as the oxide of the supported metal; the content of CeO2 in the functional carrier is at least one selected from the following: 0.8 to 4.0 wt%, 1.0 to 3.8 wt%, 1.2 to 3.5 wt%, calculated as the metal oxide.

6. The catalyst according to claim 2, wherein, The content of the hydrogenation metal active component in the catalyst is at least one selected from the following: 0.05 to 2.5 wt%, 0.06 to 2.0 wt%, 0.08 to 1.5 wt%, 0.1 to 1.5 wt%, 0.4 to 1.5 wt%.

7. The catalyst according to claim 2, characterized in that, The particle size D50 of the hydrogenation metal active component is at least one selected from the following: 1 to 5 nm, 3 to 7 nm, 5 to 9 nm.

8. The catalyst according to claim 2, wherein The proportion of the mesopore volume in the functional carrier of the catalyst to the total pore volume ≥ 60 vol%; the total pore volume is 0.35 - 0.55 cm 3 / g, the most probable distribution is 10 - 100 nm, and the pore volume refers to the pore volume with a pore diameter greater than or equal to 2 nm and less than or equal to 100 nm.

9. The catalyst according to claim 2, characterized in that, The atomic molar ratio of the promoter metal to the hydrogenation metal active component is at least one selected from the following: (0.1 to 20):1, (0.5 to 18):1, (2 to 10):

1.

10. A method for preparing the catalyst according to any one of claims 1-9, comprising the following steps: (1) Select a high-silica Y-type zeolite I with a silica-alumina ratio of 10 to 90 and perform ion exchange with a salt containing Ag ions, and obtain an Ag-containing Y-type zeolite II after low-temperature calcination; (2) Mix the Y-type zeolite II obtained in step (1) with an aqueous solution of a Ce salt, add an aqueous ammonia solution for precipitation, and obtain a functional carrier I after filtration, drying, and calcination; (3) Prepare an aqueous solution by mixing a compound containing a hydrogenation metal active component and a salt of a promoter metal, and slowly add a surfactant under stirring conditions to obtain an active metal salt solution with uniform metal dispersion; (4) Slowly add the active metal salt solution prepared in step (3) into the suspension formed by slurrying the functional support I and water, stir evenly, adjust the pH of the mixed solution to alkaline by adding an alkaline pH regulator, filter, wash, dry and calcine the obtained substance to obtain the catalyst.

11. The method according to claim 10, wherein: Step (1) also includes selecting a Y-type molecular sieve with a silica-alumina ratio of 5.5 or 5 - 190 and an acidic aqueous solution of ammonium salt through multiple ammonium exchange and multiple steam calcination processes to obtain high-silica Y-type molecular sieve I; the ammonium salt includes one or more selected from ammonium chloride, ammonium sulfate, ammonium bicarbonate, ammonium nitrate, ammonium fluorosilicate, ammonium persulfate, and ammonium acetate.

12. The method according to claim 11, characterized in that: In step (1), the "multiple" is two times. In the two ammonium exchange processes, the mass ratio of Y-type molecular sieve: ammonium salt: water is 1:(1 - 3):(5 - 20), the temperature is 50 - 100 °C, and the acidic solution pH regulator is selected from one or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and citric acid, and the pH value regulation range is 1 - 6; in the two calcination processes, the treatment atmosphere is a nitrogen-oxygen mixed gas or water vapor, where the volume ratio of nitrogen to oxygen is 2.0 - 8.0, the calcination temperature is 400 - 800 °C, and the calcination time is 0.5 - 12 hours; in step (1), the salt of Ag ion is silver nitrate; the mass ratio of the high-silica Y-type molecular sieve I to water is 1:(5 - 20); the ion exchange temperature is 40 - 90 °C, and the exchange time is 0.5 - 12 hours; the low-temperature calcination temperature is 100 - 400 °C, the calcination time is 1 - 12 hours, and the calcination atmosphere is one of nitrogen and argon atmospheres; in the Ag-containing Y-type molecular sieve II, the high-silica Y-type molecular sieve I is 1:(0.01 - 0.2) based on dry basis:Ag2O.

13. The method according to claim 10, characterized in that: In step (2), the Ce salt is one or more mixtures selected from trivalent cerium oxalate nonahydrate, cerium nitrate hexahydrate, cerium carbonate dihydrate, and cerium chloride hexahydrate / heptahydrate; the concentration of the ammonia water is 25 - 28 wt%; the conditions are that the weight ratio of the Ag-containing molecular sieve based on dry weight, the Ce salt based on the weight of Ce2O3, and water is 1:(0.005 - 0.05):(5 - 10), the temperature is from room temperature to 95 °C, and the time is 0.5 - 8 hours; the pH after precipitation with the ammonia water solution is 8 - 14; for the calcination, the treatment atmosphere is a nitrogen-oxygen mixed gas or water vapor, where the volume ratio of nitrogen to oxygen is (1 - 5):1; the calcination temperature is 350 - 800 °C; the calcination time is 0.5 - 12 hours.

14. The method according to claim 10, wherein: The compound containing a hydrogenation metal active component described in step (3) includes one or more mixtures selected from palladium acetate, palladium diammine dichloride, palladium nitrate dihydrate, ammonium tetrachloropalladate, potassium tetrabromopalladate, dichlorobis(acetonitrile)palladium(II), palladium chloride, and palladium nitrate; the promoter metal includes one or more mixtures selected from nitrate compounds, sulfate compounds, and chlorides of Co, Ni, Mo, W, Zn, La, and Cu elements; the concentration of the aqueous solution of the compound containing the hydrogenation metal active component is 0.001 - 0.025 mol / L, and the molar ratio of the hydrogenation metal active component to the promoter metal atoms is selected to be 1:(0.1 - 30); the surfactant includes one or several selected from sulfonates of fatty acid methyl ester ethoxylates, dodecyldimethylbetaine, coconut amide propyl hydroxysulfobetaine, lauramidopropyl betaine, and 2-dodecyl-N-hydroxyethyl-N-carboxymethylimidazoline, and the concentration of the surfactant is 0.001 - 0.040 mol / L; the dropping and mixing temperature of the surfactant is 40 - 80 °C.

15. The method according to claim 10, wherein: The functional carrier I is slurried with water under the conditions that the weight ratio of the functional carrier I to water based on the dry weight is 1:(2 - 10), the stirring temperature is from room temperature to 100 °C, and the time is 0.5 - 12 hours; the pH regulator is at least one of sodium hydroxide, potassium hydroxide, ammonia water, and urea; the pH value of the alkaline mixed solution is 9 - 14; the drying temperature is 100 - 150 °C, and the drying time is 12 - 24 hours; the calcination temperature is 400 - 600 °C, and the time is 4 - 12 hours; the calcination atmosphere is a mixture of nitrogen and oxygen, and the volume ratio of nitrogen to oxygen is (1 - 5):1; the content of the hydrogenation metal active component is 0.1 - 2 wt%; the particle size of the hydrogenation metal active component is 1 - 5 nm.

16. A method for selective hydrogenation of olefins, characterized in that, Using the catalyst according to any one of claims 1 - 9 to catalyze the selective hydrogenation reaction of the olefin, the olefin includes at least one selected from 1,3 - butadiene, 1,3 - pentadiene, 1,4 - pentadiene, cyclopentadiene, branched - chain cyclopentadiene, cyclohexadiene, and branched - chain cyclohexadiene.

17. The method according to claim 16, which is used for the selective hydrogenation of diolefins in the C5 fraction of the by - products of coal - based MTO.

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