Method for driving reverse water-gas shift reaction by photo-thermal

Abstract

The application provides application of a loaded high-entropy alloy as a catalyst in preparation of CO from a CO2 source and a H2 source. The application also discloses a corresponding high-efficiency sustainable photothermal driving reverse water-gas shift reaction (RWGS), and the specific high-entropy alloy catalyst used has good photothermal conversion efficiency, can efficiently drive the RWGS reaction under only illumination, and does not need external heating. The process not only helps to alleviate the greenhouse effect but also improves energy utilization efficiency, greatly reduces production cost and energy consumption. The method provided by the application has a CO generation rate of 11 mol g ‑1 h ‑1 The above has a selectivity as high as 100%, and the catalyst can be stably operated for more than 500 hours, has the advantages of simple reaction process, short cycle, cheap and easily available catalyst and reusability, and provides a new synthesis route for preparation of CO by the RWGS reaction, and has a wide industrial application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of reverse water-gas shift reaction, and relates to the use of a loaded high-entropy alloy as a catalyst in the process of preparing CO from a CO2 source and an H2 source, and a method for reverse water-gas shift reaction, and in particular to the use of a loaded high-entropy alloy as a catalyst in the process of preparing CO from a CO2 source and an H2 source, and a method for photothermal driven reverse water-gas shift reaction. Background Art

[0002] With rapid population growth and technological advancement, fossil energy is being mined and consumed at a rapid pace, leading to increasing levels of CO2 in the atmosphere and causing environmental problems such as the global greenhouse effect and ocean acidification. Developing clean energy and reducing excessive CO2 emissions are of great significance.

[0003] The RGWS reaction can convert greenhouse gas CO2 into CO. As a typical CO2 utilization technology, it has been widely studied and is of great significance for reducing CO2 emissions and achieving the dual carbon goals. The product of the RGWS reaction, CO, is an important chemical raw material and can be directly used as a raw material for the Fischer-Tropsch synthesis reaction to produce high-value-added chemicals, which is more conducive to industrial application. However, due to the high dissociation energy of the C=O bond (~750kJ mol -1 Due to the heat-absorbing nature of the RWGS reaction and the high reaction temperature (e.g., 300-600°C, 2-5 MPa), the RGWS reaction typically requires high operating temperatures and pressures (e.g., 300-600°C, 2-5 MPa). Such high reaction temperatures result in significant energy consumption and increased operating costs. Furthermore, high temperatures and a strongly reducing atmosphere often lead to catalyst sintering, hindering industrial application.

[0004] Therefore, how to find a suitable way to overcome the above-mentioned defects of the existing RGWS reaction and develop RGWS reaction technology under mild conditions is imperative and is also one of the focuses of widespread attention of many forward-looking researchers in this field. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide the use of a supported high-entropy alloy as a catalyst in the process of preparing CO from a CO2 source and an H2 source, as well as a method for the reverse water-gas shift reaction, particularly a method for photothermally driven reverse water-gas shift reaction. The present invention applies a supported high-entropy alloy to the RGWS reaction, resulting in a photothermally driven RGWS reaction method that can achieve efficient, highly selective, and highly stable production of CO under mild conditions. Moreover, the preparation method has simple synthetic steps and mild conditions, making it suitable for large-scale production promotion and application, and has good practical prospects.

[0006] The present invention provides the use of a supported high entropy alloy as a catalyst in a process of preparing CO from a CO2 source and an H2 source.

[0007] Preferably, the metals in the high entropy alloy include four or more of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt;

[0008] The supported carrier includes a metal oxide carrier.

[0009] Preferably, the molar ratio of the high entropy alloy to the carrier is (0.005-0.2):1;

[0010] The metal oxide support includes one or more of TiO2, CeO2, ZnO, MgO and Al2O3;

[0011] The preparation conditions include preparing under energized conditions.

[0012] Preferably, the preparation time is 0.1 to 1000 hours;

[0013] The energy-enabling method includes light and / or heating;

[0014] The illumination intensity of the illumination is 10 to 5000 mW / cm 2 .

[0015] Preferably, the light source of the illumination includes one or more of natural light, xenon lamp, LED lamp, tungsten lamp and mercury lamp;

[0016] The temperature of the illumination is room temperature;

[0017] The heating temperature is 20-600°C.

[0018] Preferably, the CO2 source includes CO2 or a gas containing CO2;

[0019] The H2 source includes H2 or a gas containing H2;

[0020] The CO2 source and H2 source include a mixture of CO2 and H2 or a mixture containing CO2 and H2;

[0021] The molar ratio of the metal elements in the high entropy alloy is 1:1.

[0022] The present invention provides a method for reversing the water-gas reaction, comprising the following steps:

[0023] Under energized conditions, CO2 source and H2 source are subjected to a reverse water-gas shift reaction in the presence of a supported catalyst loaded with a high-entropy alloy to produce CO.

[0024] Preferably, the metals in the high entropy alloy include four or more of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt;

[0025] The molar ratio of the high entropy alloy to the supported carrier is (0.005-0.1):1;

[0026] The support includes a metal oxide support.

[0027] Preferably, the pressure of the CO2 source is 0.1 to 10 MPa;

[0028] The pressure of the H2 source is 0.1-10 MPa;

[0029] The energy-enabling method includes light irradiation and / or heating.

[0030] Preferably, the illumination intensity of the illumination is 10 to 5000 mW / cm 2 ;

[0031] The heating temperature is 20-600°C;

[0032] The preparation time is 0.1 to 1000 hours;

[0033] The reactor for performing the reverse water gas shift reaction includes one or more of a quartz reactor, a glass reactor, a fixed bed reactor and a mobile phase reactor.

[0034] The present invention provides the use of a supported high-entropy alloy as a catalyst in the CO production process using CO2 and H2 sources. Compared to existing technologies, based on the international development trends of thermally catalyzed RGWS reactions and photocatalytic CO2 reduction, the present invention believes that the development of ideal design theories and preparation methods for photothermal-driven RGWS reactions, and the establishment of a rational and reliable photothermal-driven RGWS reaction, are the technical directions for related research.

[0035] Based on this, the present invention creatively applies a supported high entropy alloy as a catalyst in the process of preparing CO from a CO2 source and a H2 source. The present invention also discloses a corresponding efficient and sustainable photothermal driven reverse water gas change reaction (RWGS: ), the present invention utilizes a high entropy alloy supported on a commercial oxide carrier as a catalyst, and in a mobile phase reactor, under external energy (such as focused sunlight irradiation), converts CO2 and H2 into CO at room temperature, and the produced CO can be directly used for Fischer-Tropsch synthesis to manufacture high-value chemicals without the need for additional separation steps. The specific high entropy alloy catalyst used in the present invention has a very good photothermal conversion efficiency and can efficiently drive the RWGS reaction only under light without the need for external heating. This process not only helps to alleviate the greenhouse effect but also improves energy utilization efficiency, greatly reducing production costs and energy consumption. In addition, the method of the present invention has the advantages of a simple reaction process, a short cycle, a cheap and easily available catalyst, and reusability, etc., which provides a new synthetic route for the preparation of CO by RWGS reaction and has broad industrial application prospects.

[0036] The present invention can specifically utilize commercial TiO2-loaded high-entropy alloys as catalysts. In a mobile phase reactor, the RWGS reaction can be efficiently driven using only focused sunlight. The product contains no hydrocarbons or alcohols and can be directly used for Fischer-Tropsch synthesis to produce high-value hydrocarbons and oil chemicals. The catalyst has high stability and can operate stably for more than 500 hours without catalyst sintering or carbon deposition. The high-entropy alloy catalyst used in the present invention has excellent photothermal conversion efficiency. The local temperature of the catalyst surface can reach 500°C under focused sunlight radiation, and the RWGS reaction can be efficiently driven under mild conditions. This process not only helps alleviate the greenhouse effect but also improves energy efficiency, greatly reducing production costs and energy consumption.

[0037] Experimental results show that the reverse water gas change reaction method provided by the present invention can efficiently drive the RWGS reaction in a mobile phase reactor using only focused sunlight irradiation, and can convert equal volumes of CO2 and H2 into CO under mild conditions, with a production rate of product CO as high as 11 mol g -1 h -1 The selectivity is as high as 100%, and the catalyst can operate stably for more than 500 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The CO generation rate and selectivity obtained in the RWGS reaction provided in Example 1 of the present invention;

[0039] Figure 2 This is the reusability performance result of the TiO2-loaded high-entropy alloy catalyst provided by the present invention. DETAILED DESCRIPTION

[0040] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the claims of the invention.

[0041] All raw materials of the present invention are not particularly limited in their sources and can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.

[0042] The raw materials used in the present invention are not particularly limited in purity. The raw materials used in the present invention are preferably analytically pure or photothermally driven reverse water gas change reaction (RWGS: ) The conventional purity in the application field is sufficient.

[0043] All raw materials of the present invention, their brands and abbreviations are conventional brands and abbreviations in the field. Each brand and abbreviation is clear and unambiguous in the field of its relevant use. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand, abbreviation and corresponding use.

[0044] The abbreviations of all processes of the present invention are conventional abbreviations in the field. Each abbreviation is clear and unambiguous in the field of its relevant use. Those skilled in the art can understand its conventional process steps based on the abbreviations.

[0045] The present invention provides the use of a supported high entropy alloy as a catalyst in a process of preparing CO from a CO2 source and an H2 source.

[0046] In the present invention, the metals in the high entropy alloy preferably include four or more of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt, and more preferably four, five or six of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt.

[0047] In the present invention, the supported carrier preferably includes a metal oxide carrier.

[0048] In the present invention, the molar ratio of the high entropy alloy to the carrier is preferably (0.005-0.2):1, more preferably (0.05-0.16):1, and even more preferably (0.1-0.12):1.

[0049] In the present invention, the metal oxide support includes one or more of TiO2, CeO2, ZnO, MgO and Al2O3, more preferably TiO2, CeO2, ZnO, MgO or Al2O3.

[0050] In the present invention, the preparation conditions preferably include preparation under energized conditions.

[0051] In the present invention, the preparation time is preferably 0.1 to 1000 hours, more preferably 1 to 800 hours, more preferably 10 to 600 hours, and more preferably 100 to 400 hours.

[0052] In the present invention, the energy imparting method preferably includes illumination and / or heating, more preferably illumination, and specifically focused sunlight.

[0053] In the present invention, the illumination intensity of the illumination is preferably 10 to 5000 mW / cm 2 , more preferably 100 to 4000 mW / cm 2 , more preferably 1000 to 3000 mW / cm 2 .

[0054] In the present invention, the light source of the illumination preferably includes one or more of natural light, xenon lamp, LED lamp, tungsten lamp and mercury lamp, more preferably natural light, xenon lamp, LED lamp, tungsten lamp or mercury lamp.

[0055] In the present invention, the temperature of the light irradiation is preferably room temperature.

[0056] In the present invention, the heating temperature is preferably 20 to 600°C, more preferably 100 to 500°C, and even more preferably 200 to 400°C.

[0057] In the present invention, the CO 2 source preferably includes CO 2 or a gas containing CO 2 .

[0058] In the present invention, the H2 source preferably includes H2 or a gas containing H2.

[0059] In the present invention, the CO2 source and H2 source preferably include a mixed gas of CO2 and H2 or a mixed gas containing CO2 and H2.

[0060] In the present invention, the molar ratio of the metal elements in the high entropy alloy is preferably 1:1.

[0061] The present invention provides a method for reversing the water-gas reaction, comprising the following steps:

[0062] Under energized conditions, CO2 source and H2 source are subjected to a reverse water-gas shift reaction in the presence of a supported catalyst loaded with a high-entropy alloy to produce CO.

[0063] In the present invention, the metal in the high entropy alloy is preferably a high entropy alloy catalyst having the ability to dissociate C-H bonds and C=O bonds and the ability to convert light into heat, and specifically preferably includes four or more of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt, and more preferably four, five or six of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt.

[0064] In the present invention, the molar ratio of the high entropy alloy to the supported carrier is (0.005-0.1):1, more preferably (0.05-0.09):1, and more preferably (0.06-0.07):1.

[0065] In the present invention, the support preferably includes a metal oxide support.

[0066] In the present invention, the pressure of the CO2 source is preferably 0.1 to 10 MPa, more preferably 1 to 8 MPa, and even more preferably 3 to 6 MPa.

[0067] In the present invention, the pressure of the H2 source is preferably 0.1 to 10 MPa, more preferably 1 to 8 MPa, and even more preferably 3 to 6 MPa.

[0068] In the present invention, the energizing method preferably includes light irradiation and / or heating, more preferably light irradiation or heating.

[0069] In the present invention, the illumination intensity of the illumination is preferably 10 to 5000 mW / cm 2 , more preferably 100 to 4000 mW / cm 2 , more preferably 1000 to 3000 mW / cm 2 .

[0070] In the present invention, the heating temperature is preferably 20 to 600°C, more preferably 100 to 500°C, and even more preferably 200 to 400°C.

[0071] In the present invention, the preparation time is preferably 0.1 to 1000 hours, more preferably 1 to 800 hours, more preferably 10 to 600 hours, and more preferably 100 to 400 hours.

[0072] In the present invention, the reactor for performing the reverse water gas shift reaction preferably includes one or more of a quartz reactor, a glass reactor, a fixed bed reactor and a mobile phase reactor, more preferably a quartz reactor, a glass reactor, a fixed bed reactor or a mobile phase reactor.

[0073] The present invention is to complete and refine the overall preparation process, better ensure the progress of the reverse water-gas shift reaction and the product composition, and further improve the efficiency, selectivity and stability of the reverse water-gas shift reaction. The above-mentioned photothermal driven reverse water-gas shift reaction method preferably includes the following steps:

[0074] A new method for the efficient and sustainable photothermal-driven reverse water-gas shift (RWGS) reaction, comprising: using a commercial TiO2-loaded high-entropy alloy as a catalyst to convert CO2 and H2 into CO at room temperature in a mobile phase reactor under external energy conditions (such as focused solar irradiation).

[0075] Specifically, the raw gas used can be in the form of pure CO2 and H2 gas, or in the form of gas containing CO2 and H2. The term "gas containing CO2 and H2" refers to a gas mixture containing CO2 and H2.

[0076] Specifically, the catalyst carrier TiO2 can be directly purchased from cheap commercial TiO2, or TiO2 with a specific structure can be synthesized according to experimental needs.

[0077] Specifically, the catalyst carrier includes but is not limited to TiO2, and other commercial oxides may also be used instead of TiO2, such as CeO2, ZnO, MgO, Al2O3, etc.

[0078] Specifically, the components of the high entropy alloy include but are not limited to at least four of Co, Fe, Ni, Cu, Ru, Au, Rh, Pd, and Pt.

[0079] Specifically, the molar ratio of the high entropy alloy and TiO2 supported in the catalyst is 0.005 to 0.1:1.

[0080] Specifically, the illumination intensity of the illumination condition is 10–4000 mW / cm 2 .

[0081] Specifically, the light source used for the illumination condition is one or more selected from natural light, xenon lamp, LED lamp, tungsten lamp and mercury lamp.

[0082] Specifically, the reaction temperature is 20-400° C. and the reaction running time is 0-500 h.

[0083] Specifically, the reactor is a quartz reactor, a glass reactor, a fixed bed reactor or a mobile phase reactor.

[0084] Specifically, the pressure of CO2 and H2 gases in the reactor is 0.1 MPa to 10 MPa.

[0085] Further,

[0086] The present invention provides a new method for photothermal driven RGWS reaction, comprising: using commercial TiO2-loaded high entropy alloy as a catalyst, in a mobile phase reactor, under focused solar light irradiation, converting equal volumes of CO2 and H2 into CO at room temperature.

[0087] In a preferred embodiment, the feed gas may be derived from pure CO2 and H2 gas, or from a gas containing CO2 and H2. The term "gas containing CO2 and H2" refers to a gas mixture containing CO2 and H2. Preferably, the gas contains CO2 and H2 in an amount greater than 10% by volume each.

[0088] In a preferred embodiment, the flow rates of the raw gas CO2 and H2 gas are 5-60 mL / min, respectively. Preferably, the flow rates of the raw gas CO2 and H2 gas are 15 mL / min, respectively.

[0089] In a preferred embodiment, the carrier TiO2 can be directly purchased from cheap commercial TiO2, or TiO2 with a specific structure can be synthesized according to experimental needs.

[0090] In a preferred embodiment, the catalyst support includes but is not limited to TiO2, and other commercial oxides may be used instead of TiO2, such as CeO2, ZnO, MgO, Al2O3, etc. Commercial anatase TiO2 is preferably used as the support.

[0091] In a preferred embodiment, the components of the carrier high entropy alloy include but are not limited to Co, Fe, Ni, Cu, Ru, Au, Rh, Pd, Pt, etc. The preferred component is a high entropy alloy of CoNiCuPdRu.

[0092] In a preferred embodiment, the molar ratio of the high entropy alloy and TiO2 supported in the catalyst is 0.005 to 0.1: 1. Preferably, the molar ratio of the high entropy alloy and TiO2 supported in the catalyst is 0.05:1.

[0093] In a preferred embodiment, the illumination intensity of the illumination condition is 10-4000 mW / cm 2 The preferred light intensity is 3000mW / cm 2 .

[0094] In a preferred embodiment, the light source used for the illumination condition is one or more selected from natural light, a xenon lamp, an LED lamp, a tungsten lamp and a mercury lamp. Preferably, the light source for the illumination condition is natural light.

[0095] In a preferred embodiment, the reaction temperature is 20-400° C. Preferably, the reaction temperature is 25° C.

[0096] The reaction is run for 0–500 h. Preferably, the reaction is run for 300 h.

[0097] In a preferred embodiment, the reactor is a quartz reactor, a glass reactor, a fixed bed reactor or a mobile phase reactor. Preferably, the reactor is a mobile phase reactor.

[0098] In a preferred embodiment, the pressure of CO2 and H2 gas in the reactor is 0.1 MPa to 10 MPa. Preferably, the pressure of CO2 and H2 gas in the reactor is 0.1 MPa.

[0099] The method of the present invention uses commercial TiO2-loaded high-entropy alloy as a catalyst and can efficiently drive the RWGS reaction in a mobile phase reactor using only focused sunlight. Equal volumes of CO2 and H2 are converted to CO under mild conditions, with a CO production rate of up to 11 mol g -1 h -1 The above, the selectivity is as high as 100%. There are no hydrocarbon and alcohol products in the product, which can be directly used for Fischer-Tropsch synthesis to produce high-value hydrocarbons and oil chemicals. The catalyst has high stability and can operate stably for more than 500 hours without catalyst sintering and carbon deposition. The high entropy alloy catalyst developed by the present invention has a very good photothermal conversion efficiency. The local temperature of the catalyst surface can be as high as 500 ° C under focused solar radiation, and the RWGS reaction can be efficiently driven under mild conditions. This process not only helps to alleviate the greenhouse effect but also improves energy utilization efficiency, greatly reducing production costs and energy consumption. In addition, the method of the present invention has the advantages of a simple reaction process, a short cycle, a cheap and easily available catalyst and reusable. It is a new synthetic route for RWGS reaction and has broad industrial application prospects.

[0100] Through in-depth research, the present inventors have prioritized the use of catalyst supports with strong carbon dioxide adsorption capacity, including but not limited to oxide materials such as TiO2, CeO2, ZnO, MgO, and Al2O3. High-entropy alloy catalysts with strong C-H and C=O bond dissociation abilities and strong photothermal conversion capabilities have been selected. High-entropy alloy components include, but are not limited to, Co, Fe, Ni, Cu, Ru, Au, Rh, Pd, and Pt. Using supported high-entropy alloys as catalysts, they achieved efficient, highly selective, and highly stable RWGS reactions to produce CO under focused sunlight.

[0101] In the method of the present invention, after the reaction is completed, the products are only CO and H2O. No additional separation steps are required, and the method can be directly used for Fischer-Tropsch synthesis to produce high-value chemicals.

[0102] In the method of the present invention, after the reaction is completed, the conversion of the feed gas CO2 and H2 and the formation rate and selectivity of the product CO can be measured by conventional means, such as, but not limited to, gas chromatography (GC). The stability of the catalyst can be measured by long-term operation under operating conditions.

[0103] In the method of the present invention, commercial TiO2 can be purchased directly as a catalyst support, or a TiO2 support can be synthesized as needed. The metal salt used can be one or more of nitrates, chlorides, and acetates. Other commercial oxides can also be used in place of TiO2, such as CeO2, ZnO, MgO, Al2O3, and the like.

[0104] In the method of the present invention, the catalyst used is the TiO2 compound of high entropy alloy loading. In the catalyst of the present invention, TiO2 as basic material is not only widely available and cheap, but also has very excellent optical properties, chemical stability, thermal stability, super hydrophilicity and non-migration. Simultaneously, the inventor has found that in the preparation process of the catalyst, by simply loading high entropy alloy, the TiO2 compound of the high entropy alloy loading obtained can be used as an efficient catalyst under specific reaction conditions by CO2 and H2 gas or containing CO2 and H2 in CO2 and H2 high selectivity is converted into CO. In addition, the inventor has also found that the TiO2 catalyst of the high entropy alloy loading used has good stability and can be stably operated more than 500h under working conditions, thus making the whole process of the present invention have great industrial application prospects.

[0105] In the method of the present invention, preferably, the molar ratio of the high entropy alloy and TiO2 supported in the catalyst is 0.05:1.

[0106] In the method of the present invention, the feed gas used may be in the form of pure CO2 and H2 gas, or in the form of a gas containing CO2 and H2. The term "gas containing CO2 and H2" refers to a gas mixture containing CO2 and H2. Preferably, the gas contains CO2 and H2 in an amount greater than 10% by volume each.

[0107] In the method of the present invention, although there is no particular limitation on the pressure of CO2 and H2 gas or gas containing CO2 and H2 in the reactor, preferably, the pressure of CO2 and H2 gas or gas containing CO2 and H2 in the reactor is 0.1 MPa to 10 MPa.

[0108] In the method of the present invention, preferably, the illumination intensity of the illumination conditions used can be 10-4000 mW / cm 2 The preferred light intensity is 3000mW / cm 2 .

[0109] In the method of the present invention, there is no particular limitation on the light source used for the illumination condition, as long as it can emit light radiation. Preferably, the light source used for the illumination condition can be one or more selected from focused sunlight, a xenon lamp, an LED lamp (i.e., a light emitting diode), a tungsten lamp, and a mercury lamp.

[0110] In the method of the present invention, the reaction temperature of the reactor is generally 20-400°C; preferably, the reaction temperature can be 20-400°C, and most preferably, the reaction is carried out at room temperature (i.e., approximately 25-30°C). If necessary, the reactor can be heated to the desired reaction temperature by conventional means such as a heating wire or a heating mantle.

[0111] In the method of the present invention, from the perspective of efficiency, the reaction can usually be stably operated for 0 to 500 hours, and more preferably the continuous operation time is 300 hours.

[0112] In the method of the present invention, there is no particular limitation on the reactor used, as long as it is a container that can withstand a certain pressure and can be sealed. For example, the reactor used can be a quartz reactor, a glass reactor, a fixed bed reactor, or a flow reactor. Preferably, the reactor is a mobile phase reactor.

[0113] In the method of the present invention, the catalyst support used is not particularly limited, and the catalyst support may be TiO2, CeO2, ZnO, MgO, Al2O3, etc. Commercial anatase TiO2 is preferably used as the support.

[0114] In the method of the present invention, the high entropy alloy used is not particularly limited, and the components of the high entropy alloy may include Co, Fe, Ni, Cu, Ru, Au, Rh, Pd, Pt, etc. Preferably, the high entropy alloy used is CoNiCuPdRu.

[0115] The present invention provides the use of a supported high-entropy alloy as a catalyst in the process of preparing CO from a CO2 source and an H2 source, as well as a method for photothermally driven reverse water-gas shift reaction. The present invention applies a supported high-entropy alloy as a catalyst in the process of preparing CO from a CO2 source and an H2 source. The present invention also discloses a corresponding new method for efficient and sustainable photothermally driven reverse water-gas shift reaction (RWGS). The present invention uses a high-entropy alloy supported on a commercial oxide carrier as a catalyst. In a mobile phase reactor, under external energy (such as focused sunlight irradiation), CO2 and H2 are converted to CO at room temperature. The produced CO can be directly used in Fischer-Tropsch synthesis to produce high-value chemicals without the need for additional separation steps. The specific high-entropy alloy catalyst used in the present invention has excellent photothermal conversion efficiency and can efficiently drive the RWGS reaction under light alone, without the need for external heating. This process not only helps to alleviate the greenhouse effect but also improves energy utilization efficiency, greatly reducing production costs and energy consumption. In addition, the method of the present invention has the advantages of a simple reaction process, a short cycle, and a cheap, readily available, and reusable catalyst. It provides a new synthetic route for the RWGS reaction to prepare CO and has broad industrial application prospects.

[0116] The present invention can specifically utilize commercial TiO2-loaded high-entropy alloys as catalysts. In a mobile phase reactor, the RWGS reaction can be efficiently driven using only focused sunlight. The product contains no hydrocarbons or alcohols and can be directly used for Fischer-Tropsch synthesis to produce high-value hydrocarbons and oil chemicals. The catalyst has high stability and can operate stably for more than 500 hours without catalyst sintering or carbon deposition. The high-entropy alloy catalyst used in the present invention has excellent photothermal conversion efficiency. The local temperature of the catalyst surface can reach 500°C under focused sunlight radiation, and the RWGS reaction can be efficiently driven under mild conditions. This process not only helps alleviate the greenhouse effect but also improves energy efficiency, greatly reducing production costs and energy consumption.

[0117] Experimental results show that the reverse water gas change reaction method provided by the present invention can efficiently drive the RWGS reaction in a mobile phase reactor using only focused sunlight irradiation, and can convert equal volumes of CO2 and H2 into CO under mild conditions, with a production rate of product CO as high as 11 mol g -1 h -1 The selectivity is as high as 100%, and the catalyst can operate stably for more than 500 hours.

[0118] In order to further illustrate the present invention, the application of the loaded high entropy alloy provided by the present invention as a catalyst in the process of preparing CO from a CO2 source and an H2 source, as well as a method for reverse water gas change reaction are described in detail below in combination with the examples. However, it should be understood that these examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are provided only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The scope of protection of the present invention is not limited to the following examples.

[0119] Catalyst preparation

[0120] The catalyst used in the present invention is prepared as follows, taking high entropy alloy-supported TiO2 as an example:

[0121] 2 g of commercial TiO2 and 400 mL of deionized water were added to a 1000 mL glass beaker. After vigorous stirring for 30 min, 5 mL of 40 mM solution of each metal precursor was added. After stirring at room temperature for 1 hour, the resulting mixture was evaporated at 100 ° C overnight to completely remove the deionized water. The resulting sample was then calcined at 400 ° C for 2 h in a 10% H2 / 90% Ar atmosphere (heating rate 5 ° C min -1 Finally, the mixture was cooled naturally to room temperature to obtain a high-entropy alloy-supported TiO2 catalyst. The molar ratio of the high-entropy alloy supported on the catalyst to the TiO2 was 0.05:1.

[0122] Based on the same procedure as above, only the amount of the metal precursor used is changed accordingly, thereby obtaining a molar ratio of TiO2 supported by the high entropy alloy of 0.005 to 0.1:1.

[0123] Based on the same procedure as above, just change the type of metal precursor used accordingly to obtain TiO2 catalysts loaded with different high entropy alloys, including but not limited to CoNiCuPdRu / TiO2, CoNiCuPdRh / TiO2, CoNiCuPdPt / TiO2, CoNiCuPdAu / TiO2, CoNiCuPtRu / TiO2, CoNiCuRhRu / TiO2, etc.

[0124] Based on the same procedure mentioned above, other high entropy alloy supported catalysts with the same metal loading were prepared by using oxide materials such as CeO2, ZnO, MgO, and Al2O3 instead of TiO2 as support materials.

[0125] Example 1

[0126] 5 mg of high-entropy alloy-supported TiO2 catalyst (CoNiCuPdRu / TiO2, where the molar ratio of CoNiCuPdRu to TiO2 is 0.05:1) was added to the mobile phase reactor (which was connected via a stainless steel valve and could be applied with a maximum pressure of 20 MPa). A cylinder containing 50% CO2 / 50% H2 was introduced into the mobile phase reactor via a pressure reducing valve. The pressure in the reactor was atmospheric pressure, and the flow rates of CO2 and H2 were 15 mL min each. -1 The total flow rate is 30 mL min -1 At room temperature (about 25°C), using focused sunlight as the light source, at 3000mW / cm 2 The reaction was carried out under irradiation intensity.

[0127] The product CO was evaluated by an online gas chromatograph (GC-2014ATFSPL, Arcarrier, Shimadzu) equipped with two flame ionization detectors (FIDs) and one thermal conductivity detector (TCD).

[0128] See also Figure 1 , Figure 1 The CO generation rate and selectivity obtained in the RWGS reaction provided in Example 1 of the present invention. Figure 1 a is the generation rate of CO, Figure 1 b is selectivity.

[0129] The product was determined by gas chromatography to be CO, with a CO generation rate of 11 mol g -1 h -1 above( Figure 1 a), selectivity above 99% ( Figure 1 b) Furthermore, the catalyst can operate continuously and stably for over 500 hours. Considering the product formation rate, selectivity, and catalyst stability, the catalyst clearly has potential for industrial application.

[0130] Example 2

[0131] The specific reaction process and detection method are the same as those in Example 1, except that CoNiCuPdRu / CeO2 is used instead of CoNiCuPdRu / TiO2 as the catalyst.

[0132] The production rate of the target product CO was 5.3 mol g -1 h -1 , with a selectivity of 97%.

[0133] Example 3

[0134] The specific reaction process and detection method are the same as those in Example 1, except that CoNiCuPdRu / ZnO replaces CoNiCuPdRu / TiO2 as the catalyst.

[0135] The production rate of the target product CO was 4.8 mol g -1 h -1 , with a selectivity of 93%.

[0136] Example 4

[0137] The specific reaction process and detection method are the same as those in Example 1, except that CoNiCuPdRu / MgO replaces CoNiCuPdRu / TiO2 as the catalyst.

[0138] The production rate of the target product CO was 3.3 mol g -1 h -1 , with a selectivity of 89%.

[0139] Example 5

[0140] The specific reaction process and detection method are the same as those in Example 1, except that CoNiCuPdRu / Al2O3 replaces CoNiCuPdRu / TiO2 as the catalyst.

[0141] The production rate of the target product CO was 5.6 mol g -1 h -1 , with a selectivity of 88%.

[0142] Example 6

[0143] The specific reaction process and detection method are the same as those in Example 1, except that CoNiCuRuRh / TiO2 replaces CoNiCuPdRu / TiO2 as the catalyst.

[0144] After testing, the production rate of the target product CO is 11 mol g -1 h -1 , with a selectivity of 99%.

[0145] Example 7

[0146] The specific reaction process and detection method are the same as those in Example 1, except that CoNiCuPdRh / TiO2 replaces CoNiCuPdRu / TiO2 as the catalyst.

[0147] After testing, the production rate of the target product CO is 8.9 molg -1 h -1 , with a selectivity of 99%.

[0148] Example 8

[0149] The specific reaction process and detection method were the same as those in Example 1, except that a 300 xenon lamp was used as the light source instead of natural sunlight.

[0150] After testing, the production rate of the target product CO is 9.9 molg -1 h -1 , with a selectivity of 99%.

[0151] Example 9

[0152] The specific reaction process and detection method are the same as those in Example 1, and the light intensity used is 4000 mW / cm 2 Light intensity alternative 3000mW / cm 2 light intensity.

[0153] After testing, the production rate of the target product CO is 13 mol g -1 h -1 , with a selectivity of 99%.

[0154] Example 10

[0155] The specific reaction process and detection method are the same as those in Example 1, using 10% CO2 / 10% H2 / 80% Ar instead of 50% CO2 / 50% H2 as the raw gas.

[0156] After testing, the production rate of the target product CO is 3.0 molg -1 h -1 , with a selectivity of 99%.

[0157] Example 11

[0158] The specific reaction process and detection method are the same as those in Example 1, except that 30% CO2 / 30% H2 / 40% Ar is used instead of 50% CO2 / 50% H2 as the raw gas.

[0159] The production rate of the target product CO was 7.0 mol g -1 h -1 , with a selectivity of 99%.

[0160] Example 12

[0161] The specific reaction process and detection method are the same as those in Example 1, except that the flow rates of CO2 and H2 are 30 mL / min each. -1 The flow rate of CO2 and H2 is 15mL / min each. -1 flow rate.

[0162] After testing, the production rate of the target product CO is 8.0 molg -1 h -1 , with a selectivity of 99%.

[0163] Example 13

[0164] The specific reaction process and detection method are the same as those in Example 1, except that the flow rates of CO2 and H2 are 5 mL / min each. -1 The flow rate of CO2 and H2 is 15mL / min each. -1 flow rate.

[0165] After testing, the production rate of the target product CO is 3.6 molg -1 h -1 , with a selectivity of 99%.

[0166] Examples 14 to 24

[0167] The specific reaction process and detection method were the same as those in Example 1. A batch reactor was used instead of a mobile phase reactor for the experiment. The recovered catalyst was used 1, 2, 3, and up to 11 times (i.e., it was reused 10 times).

[0168] See also Figure 2 , Figure 2 This is the reusability performance result of the TiO2-loaded high-entropy alloy catalyst provided by the present invention.

[0169] Depend on Figure 2 It can be seen that the catalytic efficiency (ie, the activity and selectivity of the target product) of the catalyst provided by the present invention does not decrease significantly after being reused 10 times.

[0170] The above describes in detail the use of the supported high-entropy alloy provided by the present invention as a catalyst in the process of producing CO from a CO2 source and an H2 source, as well as a method for a photothermal-driven reverse water-gas shift reaction. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above examples is intended only to facilitate understanding of the methods and core concepts of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combined method. It should be noted that, for those skilled in the art, various improvements and modifications may be made to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that may be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims, then these other embodiments are also intended to be included within the scope of the claims.

Claims

1. Application of supported high entropy alloys as catalysts in the production of CO from CO2 and H2 sources; The metals in the high entropy alloy include five or more of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt; The preparation conditions include preparing under energized conditions; The energizing method includes illumination.

2. The use according to claim 1, characterized in that The supported carrier includes a metal oxide carrier.

3. The use according to claim 2, characterized in that The molar ratio of the high entropy alloy to the carrier is (0.005-0.2):1; The metal oxide support includes TiO 2、 One or more of CeO2, ZnO, MgO and Al2O3.

4. The use according to claim 3, characterized in that The preparation time is 0.1~1000 h; The energy-enabling method includes heating; The illumination intensity of the illumination is 10-5000 mW / cm 2 .

5. The use according to claim 4, characterized in that The light source of the illumination includes one or more of natural light, xenon lamp, LED lamp, tungsten lamp and mercury lamp; The temperature of the illumination is room temperature; The heating temperature is 20-600°C.

6. The use according to claim 1, characterized in that The CO2 source includes a gas containing CO2; The H 2 source includes a gas containing H 2 .

7. The use according to claim 1, characterized in that The CO2 source and H2 source include a mixed gas containing CO2 and H2; The molar ratio of the metal elements in the high entropy alloy is 1:

1.

8. A method for reversing the water gas change reaction, characterized in that: The following steps are involved: Under energized conditions, CO2 and H2 react with each other in a reverse water-gas shift reaction under the action of a high-entropy alloy supported catalyst to produce CO. The metals in the high entropy alloy include five or more of Co, Fe, Ni, Cu, Zn, Ru, Au, Rh, Pd and Pt; The energizing method includes illumination.

9. The method according to claim 8, characterized in that The molar ratio of the high entropy alloy to the loaded carrier is (0.005-0.1):1; The support includes a metal oxide support.

10. The method according to claim 8, characterized in that The pressure of the CO2 source is 0.1~10 MPa; The pressure of the H2 source is 0.1~10 MPa; The energizing method includes heating.

11. The method according to claim 10, characterized in that The illumination intensity of the illumination is 10-5000 mW / cm 2 ; The heating temperature is 20-600°C; Preparation time is 0.1~1000 h; The reactor for performing the reverse water gas shift reaction includes one or more of a quartz reactor, a glass reactor, a fixed bed reactor and a mobile phase reactor.

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