Heteropolyacid salt supported metal-based catalyst X / Cs3MY12O40 and application thereof in preparation of acid ester through alcohol carbonylation

Abstract

The invention relates to the technical field of catalysts, and particularly discloses a heteropolyacid salt loaded metal-based catalyst X / Cs3MY12O40 and application thereof in preparation of acid ester through alcohol carbonylation, the catalyst takes high-dispersion transition metal Rh as an active component, takes a heteropolyacid salt subjected to cesium ion exchange as a carrier, and takes cesium ion exchange as a catalyst carrier, and the catalyst X / Cs3MY12O40 is prepared into a catalyst X / Cs3MY12O40 catalyst X / Cs3MY12O40. The heterogeneous catalyst provided by the invention shows excellent performance in a reaction for preparing carboxylic ester through carbonylation of monohydric alcohols such as methanol and ethanol. Wherein under the reaction conditions that the temperature is 190 DEG C and the pressure is 3.0 MPa (the molar ratio of CH3OH to HI to CH3I is 2: 1: 1), the methanol carbonylation reaction rate can reach 2452 mol mol Rh <-1 > h <-1 >, and the performance is far superior to 1474 mol mol Rh <-1 > h <-1 > (a Monsanto process) and 1700 mol mol Rh <-1 > h <-1 > (a CatvaTM process) of a traditional industrial homogeneous catalyst under the same conditions. And high carbonylation catalytic activity can still be maintained under the condition of no iodine additive. The catalyst provided by the invention has excellent stability and low Rh loading capacity (less than or equal to 0.5 wt.%), can greatly reduce the cost of an alcohol carbonylation catalytic process, and has industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of catalyst application technology, and specifically relates to a heteropolyacid salt-supported metal-based catalyst X / Cs3MY 12 O 40 And its application in alcohol carbonylation to produce acid esters. Background Art

[0002] The carbonylation reaction of monohydric alcohol compounds is an important way to synthesize high value-added chemicals such as acetic acid, propionic acid and its esters, especially in the fields of medicine, pesticides and polymer materials. TM The production of acetic acid using the carbonylation process (e.g., Acetic acid: overview and market outlook, Indian Petrochem. Conf. (2014)) accounts for approximately 85% of total acetic acid production (K. Shah, Acetic acid: overview and market outlook, Indian Petrochem. Conf. (2014)). The carbonylation of ethanol, whose products (propionic acid or methyl propionate) also have significant economic benefits in the pharmaceutical and fragrance sectors, requires more stringent reaction conditions, and the presence of β-H in the ethanol molecule easily triggers side reactions such as dehydrogenation and condensation, further complicating catalyst design and process optimization.

[0003] In recent years, heterogeneous catalytic technology has attracted extensive attention from researchers due to its easy separation and recycling characteristics. In the process of alcohol carbonylation, ethanol and other C 2+ Alcohol carbonylation is particularly sensitive to catalyst acidity. Excessively strong acidity (e.g., on a Na13X zeolite support) can easily lead to alcohol dehydration to form byproducts such as olefins (Sara Yacob, Beata A. Kilos, David G.Barton, Justin M. Notestein, Vapor phase ethanol carbonylation over Rhsupported on zeolite 13X, Applied Catalysis A: General, 2016, 520, 122-131.). Insufficient acidity, on the other hand, can hinder the effective stabilization of the reaction intermediates, making it difficult for CO molecules to insert into the C-OH bond to form the target product, significantly reducing reaction efficiency. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 The preparation method comprises loading a transition metal X on a cesium heteropolyacid salt carrier Cs3MY 12 O 40In the above, the M is selected from any one of P and Si, and the Y is selected from any one of Mo and W.

[0005] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the steps are included: Step (1) The aqueous solution of cesium salt is mixed with an aqueous solution of any of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid, dried and calcined to obtain the cesium heteropolyacid carrier Cs3MY. 12 O 40 ; Step (2) To Cs3MY 12 O 40 The precursor solution of transition metal X is added dropwise to the carrier, dried, and calcined to obtain the heteropolyacid supported metal-based catalyst X / Cs3MY. 12 O 40 Step (2) loading the transition metal X onto the cesium heteropolyacid carrier Cs3MY 12 O 40 superior.

[0006] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the cesium heteropolyacid carrier in step (1) is specifically Cs3PMo 12 O 40 、Cs4SiW 12 O 40 、Cs4SiMo 12 O 40 .

[0007] In some first aspects, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the transition metal X is selected from any one of Rh, Ir, Ni, Co, Pt, and Pd.

[0008] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the mixing in step (1) is followed by stirring, and the stirring time is 3 to 5 h. In some embodiments, the stirring time is 4 h.

[0009] In some first aspects, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the cesium salt in step (1) is selected from any one of cesium chloride, cesium carbonate, and cesium sulfate.

[0010] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the molar concentration of the aqueous solution of the cesium salt in step (1) is 0.010-0.060 mol L -1 In some embodiments, the molar concentration of the aqueous solution of cesium salt in step (1) is optionally 0.020 mol∙L -1 , 0.030 mol∙L -1 , 0.040 mol∙L -1 , 0.050 mol∙L -1 .

[0011] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the molar concentration of the aqueous solution of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid in step (1) is 0.02-0.03 mol∙L -1 In some embodiments, the molar concentration of the aqueous solution of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, and silicomolybdic acid in step (1) is 0.025 mol∙L -1 .

[0012] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, after mixing in step (1), the stirring speed is 300-600 r∙min -1 In some embodiments, after mixing in step (1), the stirring speed is optionally 400 r∙min -1 , 450 r∙min -1 , 500 r∙min -1 , 550 r∙min -1 .

[0013] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, after mixing in step (1), the mixture is further aged.

[0014] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40In a specific embodiment of the preparation method, the drying method in step (1) is drying after rotary evaporation, and the drying temperature is 60~90°C. In some embodiments, the drying method in step (1) is drying after rotary evaporation, and the drying temperature is optionally 70°C, 75°C, 80°C, or 85°C.

[0015] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the rotary evaporation temperature in step (1) is 60-80°C. In some embodiments, the rotary evaporation temperature in step (1) is optionally 64°C, 68°C, 72°C, or 76°C.

[0016] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the calcination method in step (1) is 4-6 ℃∙min -1 The temperature is raised to 300-500 °C and calcined. In some embodiments, the calcination method in step (1) is 5 °C∙min -1 Heat to 350°C and calcine.

[0017] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the calcination time in step (1) is 2 to 4 hours. In some embodiments, the calcination time in step (1) is 3 hours.

[0018] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, before adding the transition metal X solution in step (2), Cs3MY 12 O 40 The carrier is ground.

[0019] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the drying temperature in step (2) is 70-90°C. In some embodiments, the drying temperature in step (2) is optionally 75°C, 80°C, or 85°C.

[0020] In some aspects of the first aspect, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40In a specific embodiment of the preparation method, the calcination method in step (2) is 4-6 ° C∙min -1 The temperature is raised to 300-500 °C and calcined. In some embodiments, the calcination method in step (2) is 5 °C∙min -1 Heat to 350°C and calcine.

[0021] In some first aspects, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the calcination time in step (2) is 2 to 4 hours.

[0022] In some first aspects, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the precursor solution of the transition metal X is a rhodium trichloride solution.

[0023] In some first aspects, the heteropolyacid salt supported metal-based catalyst X / Cs3MY 12 O 40 In a specific embodiment of the preparation method, the transition metal X is selected from any one of Rh, Ni, Co, Pt, and Pd.

[0024] The second aspect of the present invention provides a heteropolyacid salt-supported metal-based catalyst X / Cs3MY obtained by any preparation method described in the first aspect. 12 O 40 .

[0025] The third aspect of the present invention provides a heteropolyacid salt supported metal-based catalyst X / Cs3MY as described in the second aspect. 12 O 40 Applications in batch carbonylation of monohydric alcohols to produce carboxylic acids and carboxylic acid esters include: S1: Catalyst X / Cs3MY 12 O 40 After mixing with iodide, pressurizing under CO gas atmosphere, catalyst activation pretreatment is performed to obtain X / Cs3MY after iodide activation 12 O 40 , the transition metal X is selected from any one of Rh, Ir, Ni, Co, Pt, and Pd, the M is selected from one of P and Si, and the Y is selected from one of Mo and W; S2: Separate the catalyst X / Cs3MY activated in step S1 12 O 40 The product is mixed with alcohol and pressurized under a CO atmosphere to undergo carbonylation reaction to obtain acid and / or ester.

[0026] In some specific embodiments of the application of the third aspect, the iodide in step S1 includes hydroiodic acid and methyl iodide.

[0027] In some specific embodiments of the application of the third aspect, the molar ratio of hydroiodic acid to methyl iodide in step S1 is (1~2):(1~2).

[0028] In some specific embodiments of the application described in the third aspect, in the S1 step, the CO gas atmosphere is pressurized to 2.0~4.0 MPa. In some embodiments, in the S1 step, the CO gas atmosphere is pressurized to 2.5 MPa, 3.0 MPa, or 3.5 MPa.

[0029] In some specific embodiments of the application of the third aspect, the reaction temperature of step S2 is 140-160°C. In some embodiments, the reaction temperature of step S2 is optionally 145°C, 150°C, or 155°C.

[0030] In some specific embodiments of the application described in the third aspect, the pressure in the CO gas atmosphere in the S2 step is increased to 2.0~4.0 MPa. In some embodiments, the pressure in the CO gas atmosphere in the S2 step is optionally increased to 2.5 MPa, 3.0 MPa, or 3.5 MPa.

[0031] In some specific embodiments of the application described in the third aspect, the monohydric alcohol added in step S2 is methanol, ethanol, or a mixture thereof.

[0032] In some specific embodiments of the application of the third aspect, the acid produced in the step is acetic acid, propionic acid, or a mixture thereof.

[0033] In some specific embodiments of the application of the third aspect, the ester produced in step S2 is methyl acetate, ethyl propionate, or a mixture thereof.

[0034] In some specific embodiments of the application of the third aspect, in the step S2, X / Cs3MY is added to each 1 mol of monohydric alcohol. 12 O 40 Catalyst 4-8g, in some embodiments, each 1 mol of monohydric alcohol is added with X / Cs3MY 12 O 40 The catalyst is optionally 5 g, 6 g, or 7 g.

[0035] The fourth aspect of the present invention provides an X / Cs3MY activated by iodide 12 O 40 The preparation method comprises: The heteropolyacid salt-supported metal-based catalyst X / Cs3MY12 O 40 After mixing with iodide, pressurizing under CO gas atmosphere, catalyst activation pretreatment is performed to obtain X / Cs3MY after iodide activation 12 O 40 .

[0036] The fifth aspect of the present invention provides an iodide-activated X / Cs3MY prepared by the method described in the fourth aspect. 12 O 40 .

[0037] In the present invention, Cs3PW 12 O 40 、Cs3PMo 12 O 40 、Cs4SiW 12 O 40 、Cs4SiMo 12 O 40 They are abbreviated as CsPW, CsPMo, CsSiW, and CsSiMo respectively.

[0038] In some embodiments, the room temperature is 45-5°C, in some embodiments, the room temperature is 40-10°C, in some embodiments, the room temperature is 35-15°C, in some embodiments, the room temperature is 30-20°C, and in some embodiments, the room temperature is 25°C.

[0039] The drugs used in the present invention are purchased from the open legal market and have not been further purified.

[0040] The design principles of the present invention are as follows: The present invention constructs a heterogeneous catalyst system for the carbonylation of metal-based monohydric alcohols supported by heteropolyacids, and uses heteropolyacids and cesium ions (Cs + ) combined to form a highly stable carrier: On the one hand, Cs + The electrostatic stabilization of the skeleton enhances its thermal stability. On the other hand, by adjusting the type of heteropoly anions and Cs + The degree of substitution precisely regulates the Brønsted acidity, inhibiting dehydration side reactions while retaining the ability to activate CO and alcohols. To address the defect that Rh requires HI to provide an acidic environment, this design highly disperses metallic Rh atoms on the support surface through an impregnation method, proposing a halogen-free green catalytic reaction system based on cesium heteropolyacids loaded with Rh single atoms.

[0041] This halogen-free green catalytic reaction system adopts an iodine-assisted pretreatment-reaction iodine-free strategy. First, a trace amount of iodide is used to induce Rh single atoms to disperse and anchor on the support surface, forming Rh-OW strong coordination active centers. With the help of Rh-OW strong coordination, Rh single atoms are anchored on the support surface, inhibiting the loss of metal Rh, forming stable active sites, and producing X / Cs3MY after iodide activation. 12 O 40 .

[0042] This halogen-free green catalytic reaction system does not require iodine ligands or HI to participate in the catalytic cycle, simultaneously suppresses dehydration side reactions, and achieves high activity and high stability in methanol / ethanol carbonylation under mild conditions. By pre-treating with iodine rather than directly adding iodine to the alcohol feed system, it avoids the iodine contamination, equipment corrosion, and deactivation problems of traditional processes, providing an innovative path for green chemical processes.

[0043] Advantages of the present invention: (1) The method provided by the present invention is the first to utilize cesium heteropolyacid salts loaded with transition metal-based heterogeneous catalysts for intermittent monohydric alcohol carbonylation reaction, thereby enhancing the activity and selectivity of the alcohol carbonylation reaction.

[0044] (2) The cesium heteropolyacid CsPW loaded metal Rh catalyst prepared by the present invention exhibits excellent reaction activity for alcohol carbonylation to carboxylic esters. The methanol carbonylation reaction rate can reach 2452 mol∙mol under the reaction conditions of 190 °C and 3.0 MPa. Rh -1 ∙h -1 , the performance is far superior to traditional industrial homogeneous catalysts; under the reaction conditions of 150 ℃ and 3.0 MPa, the ethanol carbonylation reaction rate can reach 41.1 mol∙mol Rh -1 ∙h -1 The performance can reach 40% of that of homogeneous catalysts. The catalyst provided by the present invention has excellent catalytic activity and stability, and a low Rh loading (≤0.6 wt.%), which can greatly reduce the cost of the alcohol carbonylation catalytic process and has industrial application prospects.

[0045] (3) Some scholars have applied Rh / cesium heteropolyacid salts to continuous ethanol carbonylation. However, there are many side reactions, which significantly affect the selectivity of carbonylation products (Park, Sunyoung, Kilos, et al. Vapor-phase ethanol carbonylation with heteropolyacid-supported Rh [J]. Journal of Catalysis, 2015.). Compared with the existing technology, the catalyst provided by the present invention can still catalyze the alcohol carbonylation reaction in the absence of iodine after being activated by iodide and CO in the reaction system.

[0046] This design uses X / Cs3MY after iodide activation. 12 O 40 Significantly different from traditional alcohol carbonylation systems that rely on the continuous addition of iodide, this innovative "iodine pretreatment activation-iodine-free reaction" strategy (i.e., Examples 10 and 10-1) not only avoids iodide-induced equipment corrosion but also enables alcohol carbonylation without iodine additives through the Rh-I active sites formed during pretreatment. This work, for the first time, proposes and verifies the sustained activity of a catalyst without a halogen additive, providing a new approach to green carbonylation processes and promising industrial applications with both high stability and simplified product separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The X-ray diffraction pattern of the metal Rh supported on the cesium heteropolyacid salt catalyst in the present invention; Figure 2 This is a carbonylation activity diagram of the Rh / CsPW catalyst in the present invention when used in a continuous system without iodine additive. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to further illustrate the present invention in detail.

[0049] Below further combine embodiment to describe the present invention in detail.Should be understood that following examples are only used for further illustrating the present invention, can not be construed as limiting the scope of protection of the present invention, the specific quality, reaction time and temperature, processing parameters etc. in the example are also only an example in the appropriate range, some non-essential improvements and adjustments made by those skilled in the art according to the foregoing of the present invention all belong to protection scope of the present invention.Unindicated specific technology or condition in the embodiment, all are according to the technology or condition described in the document in this area or are carried out according to product specification.Reagents used or instrument do not indicate manufacturer, all are conventional products that can be purchased through the market.

[0050] Example 1 Preparation of Rh / CsPW catalyst: (1) Cs3PW 12 O 40 The preparation process of the carrier is as follows: phosphotungstic acid (H3PW 12 O 40 ) was dissolved in water to obtain 15 mL of 0.025 mol∙L -1 H3PW 12 O 40 The solution was stirred at 0.6 mL min using a micro-constant flow pump. -1 15 mL of 0.038 mol∙L -1 The mixed solution was then placed on a magnetic stirrer at 500 r∙min -1 Stir at a speed of 4 h.

[0051] The suspension after aging for 4 h was transferred to a 250 mL eggplant-shaped rotary evaporation flask and vacuum evaporated at 80 °C. The solid material obtained after rotary evaporation was placed in an oven at 80 °C overnight and then placed in a muffle furnace at 5 °C∙min. -1 The temperature was raised to 350℃ and calcined for 3 h to obtain Cs3PW. 12 O 40 carrier.

[0052] (2) The process of loading metal Rh by impregnation is as follows: Taking the preparation of 1 g of Rh / CsPW as an example, 0.46 mmol of RhCl3∙3H2O was dissolved in 0.46 mL of deionized water, and then the solution was added dropwise to the CsPW support. After being fully ground, it was placed in an 80 °C oven to dry overnight, and finally placed in a muffle furnace at 5 °C∙min -1 The temperature was raised to 350 °C and calcined for 3 h to obtain the Rh / CsPW catalyst.

[0053] The steps for evaluating the performance of alcohol carbonylation reaction are as follows: (1) 0.3 g of the prepared Rh / CsPW catalyst was added to the polytetrafluoroethylene liner of a batch reactor. The methanol / ethanol system was then designed as shown in Table 1. Alcohol and iodide were added to the reactor liner using the feed amounts listed in Table 1. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to the reaction pressure, and the alcohol carbonylation reaction was initiated. The specific reaction conditions were as follows: reaction temperature of 150 °C, reaction CO pressure of 3.0 MPa, and rotation speed of 500 r / min.

[0054] Table 1

[0055] (2) Carbonylation activity was determined by off-line quantitative analysis using a gas chromatograph using the internal standard method. The results are shown in Table 2.

[0056] Example 2 Rh / CsSiW(Rh / Cs4SiW 12 O 40 ) The preparation of the catalyst is similar to that of Example 1, except that 1.08 g of H3PW in step (1) is used as the catalyst. 12 O 40 Replaced with 1.08 g of H4SiW 12 O 40 , 0.038 mol∙L -1 of Cs2CO3 was replaced with 0.050 mol∙L -1 , the other conditions are the same.

[0057] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 2.

[0058] Example 3 Rh / CsPMo(Rh / Cs3PMo 12 O 40 ) The preparation of the catalyst is similar to that of Example 1, except that 1.08 g of H3PW in step (1) is used as the catalyst. 12 O 40 Replaced with 1.01 g of H3PMo 12 O 40 , 0.038 mol∙L -1 of Cs2CO3 was replaced by 0.056 mol∙L -1 , the other conditions are the same.

[0059] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 2.

[0060] Example 4 Rh / CsSiMo(Rh / Cs4SiMo 12 O 40 ) The preparation of the catalyst is similar to that of Example 1, except that 1.08 g of H3PW in step (1) is used as the catalyst. 12 O 40 Replaced with 5.04 g of H4SiMo 12 O 40 Solution (mass fraction 25%), 0.038 mol∙L -1 of Cs2CO3 was replaced by 0.074 mol∙L -1 , the other conditions are the same.

[0061] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 2.

[0062] Table 2. Carbonylation activity of the catalysts in Examples 1 to 4 at 150 °C and 3.0 MPa As shown in Table 2, the type of heteropolyacid support has a significant effect on the carbonylation reaction rate. When the heteropolyacid support is CsPW, the carbonylation rate in the methanol system can reach 148.8 mmol·L -1 ·h -1 , in ethanol system it can reach 20.0mmol·L -1 ·h -1 The methanol conversion rate reached 81.9%, and the ethanol conversion rate was 14.7%. Furthermore, it can be seen that the heteropolyacid-supported metal Rh catalyst exhibited excellent carbonylation selectivity in both methanol and ethanol systems.

[0063] Example 5 The preparation of Ni / CsPW catalyst was similar to that in Example 1, except that 0.46 mmol of RhCl3∙3H2O in step (2) was replaced with 0.253 mL of Ni(NO3)2 solution (concentration of 0.025 g∙mL -1 ), the other conditions are the same.

[0064] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 3.

[0065] Example 6 The preparation of Co / CsPW catalyst was similar to that in Example 1, except that 0.46 mmol of RhCl3∙3H2O in step (2) was replaced with 31.2 mg of Co(NO3)2∙6H2O, and the other conditions were the same.

[0066] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 3.

[0067] Example 7 The preparation of Pt / CsPW catalyst was similar to that in Example 1, except that 0.46 mmol of RhCl3∙3H2O in step (2) was replaced with 0.267 mL of Pt(NO3)2 solution (concentration of 0.024 g∙mL -1 ), the other conditions are the same.

[0068] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 3.

[0069] Example 8 The preparation of Pd / CsPW catalyst was similar to that in Example 1, except that 0.46 mmol of RhCl3∙3H2O in step (1) was replaced with 1.130 mL of Pd(NO3)2∙2H2O solution (concentration of 0.014 g∙mL -1 ), the other conditions are the same.

[0070] The steps for evaluating the carbonylation reaction performance were as described in Example 1, and the reaction results are shown in Table 3.

[0071] Table 3. Carbonylation reaction rates of the catalysts in Examples 5-8 at 150 °C and 3.0 MPa As can be seen from Table 3, the type of transition metal has a significant effect on the carbonylation reaction rate. When the metals in Examples 5 to 8 are loaded, the carbonylation rate is relatively low in both the methanol system and the ethanol system, and the activity is lower than that of metal Rh.

[0072] Example 10 Iodide-free batch carbonylation experiment of Rh / CsPW catalyst after iodide pretreatment: Methanol system: (1) 0.3 g of the prepared Rh / CsPW catalyst was added to the polytetrafluoroethylene lining of a high-temperature, high-pressure reactor. Subsequently, 0.025 mol of hydroiodic acid and 0.025 mol of methyl iodide were added to the reactor lining, but no methanol was added. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to 3.0 MPa to obtain iodide-activated Rh / CsPW.

[0073] (2) 0.3 g of the iodide-activated Rh / CsPW obtained in step (1) was added to the polytetrafluoroethylene lining of a high-temperature, high-pressure reactor. 0.05 mol of methanol was then added to the reactor lining, but hydroiodic acid and methyl iodide were not added. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to 3.0 MPa, the reaction temperature was 150 °C, and the rotation speed was 500 r / min to initiate the alcohol carbonylation reaction. The reaction results are shown in Table 4.

[0074] In Example 10, step (1) is to pre-treat the catalyst Rh / CsPW with iodide using 0.025 mol of hydroiodic acid and 0.025 mol of methyl iodide to obtain iodide-activated Rh / CsPW. In step (2), the iodide-activated Rh / CsPW is then added to methanol for carbonylation reaction to obtain acetic acid and methyl acetate.

[0075] Example 10-1 Iodide-free batch carbonylation experiment of Rh / CsPW catalyst after iodide pretreatment: Ethanol system: (1) 0.3 g of the prepared Rh / CsPW catalyst was added to a polytetrafluoroethylene liner in a high-temperature, high-pressure reactor. Subsequently, 0.025 mol of hydroiodic acid and 0.025 mol of ethyl iodide were added to the reactor liner, but no ethanol was added. The reactor was then purged with N2 three times and then with CO3 three times. Finally, the CO2 pressure was increased to 3.0 MPa to obtain iodide-activated Rh / CsPW.

[0076] (2) 0.3 g of the iodide-activated Rh / CsPW obtained in step (1) was added to the polytetrafluoroethylene lining of a high-temperature, high-pressure reactor. 0.05 mol of ethanol was then added to the reactor lining, but hydroiodic acid and ethyl iodide were not added. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to 3.0 MPa, the reaction temperature was 150°C, and the rotation speed was 500 r / min to initiate the alcohol carbonylation reaction. The reaction results are shown in Table 4.

[0077] In Example 10-1, step (1) the catalyst Rh / CsPW is pretreated with iodide using 0.025 mol of hydroiodic acid and 0.025 mol of iodine to obtain iodide-activated Rh / CsPW. In step (2), the iodide-activated Rh / CsPW is added to ethanol for carbonylation reaction to obtain propionic acid and ethyl propionate.

[0078] Example 11 Iodine-free batch carbonylation experiment of Rh / CsPW catalyst after carbonylation of iodine-containing alcohols: Methanol system: (1) 0.3 g of the prepared Rh / CsPW catalyst was added to the polytetrafluoroethylene lining of a batch reactor, and 0.05 mol of methanol, 0.025 mol of hydroiodic acid, and 0.025 mol of methyl iodide were added to the reactor lining. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to a reaction pressure of 3.0 MPa, a reaction temperature of 150 °C, and a rotation speed of 500 r / min. The alcohol carbonylation reaction was then started to obtain Rh / CsPW after the alcohol carbonylation reaction.

[0079] (2) 0.3 g of the Rh / CsPW obtained in step (1) after the alcohol carbonylation reaction was added to the polytetrafluoroethylene lining in a high-temperature and high-pressure reactor. Subsequently, 0.05 mol of methanol was added to the reactor lining, but no hydroiodic acid and methyl iodide were added. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to 3.0 MPa. The reaction temperature was 150 °C, the reaction time was 8 h, and the rotation speed was 500 r / min. Then, the alcohol carbonylation reaction was started. The results are shown in Table 4.

[0080] Example 11-1 Iodine-free batch carbonylation experiment of Rh / CsPW catalyst after carbonylation of iodine-containing alcohols: Ethanol system: (1) 0.3 g of the prepared Rh / CsPW catalyst was added to the polytetrafluoroethylene lining in a batch reactor, and then 0.05 mol of ethanol, 0.025 mol of hydroiodic acid, and 0.025 mol of ethyl iodide were added to the reactor lining. The reactor was then purged with N2 three times and then with CO three times. Finally, CO was charged to 3.0 MPa, the reaction temperature was 150 °C, the rotation speed was 500 r / min, and then the alcohol carbonylation reaction was started to obtain Rh / CsPW after the alcohol carbonylation reaction.

[0081] (2) 0.3 g of the Rh / CsPW obtained in Group 2 after the alcohol carbonylation reaction was added to the polytetrafluoroethylene lining of a high-temperature and high-pressure reactor. Subsequently, 0.05 mol of ethanol was added to the reactor lining, but no hydroiodic acid or ethyl iodide was added. The reactor was then purged with N2 three times and then with CO3 three times. Finally, CO was charged to 3.0 MPa. The reaction temperature was 150 °C, the reaction time was 12 h, and the rotation speed was 500 r / min. The alcohol carbonylation reaction was then started. The results are shown in Table 4.

[0082] Comparative Example 1 Iodine-free batch carbonylation experiment of untreated Rh / CsPW catalyst: Methanol system: 0.3 g of the prepared Rh / CsPW catalyst was added to the polytetrafluoroethylene lining of a high-temperature, high-pressure reactor. Subsequently, 0.05 mol of methanol was added to the reactor lining, but no iodide (hydriodic acid and methyl iodide) was added. The reactor was then purged three times with nitrogen and then three times with carbon monoxide. Finally, carbon monoxide was added to the reaction pressure, and the alcohol carbonylation reaction was initiated. The specific reaction conditions were as follows: reaction temperature 150°C, reaction CO pressure 3.0 MPa, reaction time 8 h, and rotation speed 500 rpm. The reaction results are shown in Table 4.

[0083] Comparative Example 2 Iodine-free batch carbonylation experiment of untreated Rh / CsPW catalyst: Ethanol system: 0.3 g of the prepared Rh / CsPW catalyst was added to the polytetrafluoroethylene lining of a high-temperature, high-pressure reactor. Subsequently, 0.05 mol of ethanol was added to the reactor lining, but no iodide (hydriodic acid and ethyl iodide) was added. The reactor was then purged three times with N2 and then three times with CO. Finally, CO was added to the reaction pressure, and the alcohol carbonylation reaction was initiated. The specific reaction conditions were as follows: reaction temperature 150°C, reaction CO pressure 3.0 MPa, reaction time 12 h, and rotation speed 500 rpm. The reaction results are shown in Table 4.

[0084] Table 4. Carbonylation reaction rates of the catalysts in Examples 10, 11 and Comparative Examples 1, 2 at 150°C and 3.0 MPa

[0085] The experimental data in Table 4 show that the 0.5 wt.% Rh / CsPW catalysts that underwent iodide pretreatment (i.e., Example 10 and Example 10-1) and the iodine-assisted carbonylation reaction followed by the intermittent alcohol carbonylation experiment without the iodine-assisted catalyst (i.e., Example 11 and Example 11-1) exhibited better catalytic performance in the carbonylation of alcohols. The carbonylation rates of Example 10 and Example 10-1, which were pretreated with iodide, reached 21.4 mmol·L -1 ·h -1 , which is much higher than the methods of Example 11 and Example 11-1.

[0086] When the alcohol carbonylation experiment without iodine additive was carried out directly without any treatment (i.e., Comparative Examples 1 and 2), the carbonylation rate of the methanol system was 3.1 mmol·L -1 ·h -1 , while the ethanol system is only 0.01 mmol·L -1 ·h -1 , which is almost negligible.

[0087] Example 12 Continuous carbonylation experiment without iodine promoter over Rh / CsPW catalyst after iodide pretreatment: 0.5 g of the prepared Rh / CsPW catalyst was added to a fixed bed continuous reactor, and then introduced into the reactor at a partial pressure ratio of CO:EtI:HI = 164:1:1 to perform iodide pretreatment to obtain the iodide-pretreated Rh / CsPW catalyst, wherein the activation temperature was 150 °C and the WHSV was 4.7 h -1 .

[0088] After the iodide pretreatment, the iodide-pretreated Rh / CsPW catalyst was obtained. CO and EtOH were introduced into the device at a partial pressure ratio of CO:EtOH = 16.4:1. Then, the reaction temperature was 150 °C and the WHSV was 4.7 h. -1 The alcohol carbonylation experiment without iodine auxiliary was carried out under the following conditions. Figure 2 .

[0089] Depend on Figure 1 It can be seen that only characteristic diffraction peaks of the support were observed for the Rh / cesium heteropolyacid catalysts (Rh / CsPW, Rh / CsSiW, Rh / CsPMo, and Rh / CsSiMo), with no obvious diffraction peaks characteristic of Rh particles detected. This indicates that the Rh-based catalysts prepared by the method provided herein exhibit highly dispersed Rh on the various heteropolyacid supports, with no apparent Rh particle aggregation.

[0090] Depend on Figure 2 It can be seen that in the first 4 h of the continuous reaction of the Rh / CsPW catalyst, only EtI, HI and CO were introduced, and it can be seen that only ethylene was detected at this time; EtOH and CO were then introduced into the fixed bed. It was observed that the catalyst, activated by EtI, HI, and CO, still had the ability to catalyze the carbonylation of ethanol in the absence of iodide. The ethanol conversion rate was approximately 1.8%, and the selectivity for the carbonylation product, ethyl propionate, reached approximately 80%.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A heteropolyacid salt-supported metal-based catalyst X / Cs3MY 12 O 40 The preparation method is characterized in that Including, loading the transition metal X on the cesium heteropolyacid carrier Cs3MY 12 O 40 In the above, the M is selected from any one of P and Si, and the Y is selected from any one of Mo and W.

2. The preparation method according to claim 1, characterized in that Step (1) The aqueous solution of cesium salt is mixed with an aqueous solution of any of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid, dried and calcined to obtain the cesium heteropolyacid carrier Cs3MY. 12 O 40 ; Step (2) To Cs3MY 12 O 40 The precursor solution of transition metal X was added dropwise to the carrier, dried, and calcined to obtain the heteropolyacid supported metal-based heterogeneous catalyst X / Cs3MY. 12 O 40 .

3. The preparation method according to any one of claims 1 or 2, characterized in that The cesium heteropolyacid carrier in step (1) is specifically Cs3PMo 12 O 40 、Cs4SiW 12 O 40 、Cs4SiMo 12 O 40 and / or, the transition metal X is selected from any one of Rh, Ir, Ni, Co, Pt, and Pd.

4. The preparation method according to any one of claims 2 or 3, characterized in that The mixing in step (1) is followed by stirring for 3 to 5 h; and / or the cesium salt in step (1) is selected from any one of cesium chloride, cesium carbonate, and cesium sulfate; and / or the molar concentration of the aqueous solution of the cesium salt in step (1) is 0.010 to 0.060 mol L -1 ; and / or, the molar concentration of any aqueous solution of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, or silicomolybdic acid in step (1) is 0.02 to 0.03 mol∙L -1 ; and / or, after mixing in step (1), the stirring speed is 300~600 r∙min -1 .

5. The preparation method according to any one of claims 1 to 4, characterized in that After mixing in step (1), the mixture is further aged; and / or, the drying method in step (1) is drying after rotary evaporation, and the drying temperature is 60-90°C; and / or, the rotary evaporation temperature in step (1) is 60-80°C; and / or, the roasting method in step (1) is 4-6°C∙min -1 The temperature is raised to 300-500 ° C and calcined; and / or, the calcination time in step (1) is 2-4 h; and / or, before the precursor solution of transition metal X is added dropwise in step (2), Cs3MY is calcined. 12 O 40 The carrier is ground; and / or, the drying temperature in step (2) is 70-90 °C; and / or, the calcination method in step (2) is 4-6 °C∙min -1 The temperature is raised to 300-500°C and calcined; and / or, the calcination time in step (2) is 2-4 hours; and / or, the precursor solution of the transition metal X is a rhodium trichloride solution; and / or, the transition metal X is selected from any one of Rh, Ni, Co, Pt, and Pd.

6. A heteropolyacid salt-supported metal-based heterogeneous catalyst X / Cs3MY obtained by the preparation method according to any one of claims 1 to 5 12 O 40 .

7. A catalyst X / Cs3MY obtained by the preparation method according to claim 6 or any one of claims 1 to 5 12 O 40 Applications in batch carbonylation of monohydric alcohols to produce carboxylic acids and carboxylic acid esters include: S1: The catalyst X / Cs3MY according to claim 6 12 O 40 After mixing with iodide, pressurizing under CO gas atmosphere, catalyst activation pretreatment is performed to obtain X / Cs3MY after iodide activation 12 O 40 ; S2: X / Cs3MY after iodide activation in step S1 12 O 40 The product is mixed with alcohol and pressurized under a CO atmosphere to undergo carbonylation reaction to obtain acid and / or ester.

8. The application according to claim 7, characterized in that: In the step S1, the iodide comprises hydroiodic acid and methyl iodide; and / or, the molar ratio of hydroiodic acid and methyl iodide in the step S1 is (1-2): (1-2); and / or, in the step S1, the pressure is increased to 2.0-4.0 MPa under a CO gas atmosphere; and / or, the reaction temperature is 140-160°C; and / or, in the step S2, the pressure is increased to 2.0-4.0 MPa under a CO gas atmosphere; and / or, the monohydric alcohol added in the step S2 is methanol, ethanol, or a mixture thereof; and / or, the acid produced in the step is acetic acid, propionic acid, or a mixture thereof; and / or, the ester produced in the step S2 is methyl acetate, ethyl propionate, or a mixture thereof; and / or, in the step S2, X / Cs3MY is added to each 1 mol of the monohydric alcohol. 12 O 40 Catalyst 4~8 g.

9. An iodide-activated X / Cs3MY 12 O 40 The preparation method comprises: The heteropolyacid salt-supported metal-based heterogeneous catalyst X / Cs3MY according to claim 6 12 O 40 After mixing with iodide, pressurizing under CO gas atmosphere, catalyst activation pretreatment is performed to obtain X / Cs3MY after iodide activation 12 O 40 .

10. X / Cs3MY prepared by the method of claim 9 after iodide activation 12 O 40 .

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