A method for photo-thermal catalytic dehydrogenation of propane using a high-stability supported high-entropy intermetallic compound catalyst, the catalyst and application thereof

Abstract

The application discloses a photothermal catalytic propane dehydrogenation method using a high-stability supported high-entropy intermetallic compound catalyst, a catalyst and application thereof, relates to the fields of solar light concentration utilization and photothermal catalytic reaction, and is characterized in that under light conditions, light is used to drive a propane dehydrogenation reaction of a light alkane raw material gas such as propane and a supported high-entropy intermetallic compound catalyst to generate corresponding olefins and hydrogen. The application utilizes the photothermal conversion capacity of the supported high-entropy intermetallic compound catalyst under light conditions to drive the propane dehydrogenation reaction, and can reduce the dependence on a traditional external high-temperature heating mode. The high-entropy intermetallic compound has an ordered intermetallic compound structure, which is beneficial to improving the structural stability and deactivation resistance of the catalyst. The method can realize efficient and high-selectivity conversion of propane to propylene, and is suitable for continuous flow reaction. The method provides a new technical approach for propane dehydrogenation participated by solar energy or light energy.

Description

Technical Field

[0001] This invention relates to the fields of solar energy concentration utilization and photothermal catalytic reaction technology, specifically to a photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst, the catalyst itself, and its applications. Background Technology

[0002] With the rapid development of modern chemical industry, propylene, as an important basic chemical raw material, has wide applications in polyolefins, fine chemicals, synthetic rubber, and polymer materials. In recent years, with the increasing abundance of propane sources from natural gas, shale gas, and refinery by-products of light alkanes, the direct conversion of propane into propylene has become a crucial pathway to improve resource utilization efficiency and produce high-value-added chemicals. Against this backdrop, propane dehydrogenation (PDH: C3H8⇌C3H6 + H2) has emerged. This type of reaction not only directly yields high-value olefins but also produces hydrogen as a by-product, exhibiting high atom economy and industrial application value.

[0003] However, the C–H bonds in propane molecules are relatively stable, and the dehydrogenation reaction itself is a strongly endothermic process, typically requiring high reaction temperatures to proceed effectively. Existing industrial thermocatalytic processes usually rely on external high-temperature heating to overcome the activation energy barrier of alkane C–H bonds and shift the reaction equilibrium towards olefin formation. While high-temperature conditions are beneficial for improving alkane conversion, they also easily induce problems such as deep cracking, coking, and sintering, leading to decreased selectivity for target olefins, accelerated catalyst deactivation, and increased energy consumption and operating costs. Furthermore, in traditional thermocatalytic systems, heat is usually provided by the furnace body or heat transfer medium, and energy utilization efficiency is limited by factors such as the heat transfer process, reactor structure, and catalyst bed temperature distribution, making it difficult to simultaneously achieve high conversion rates, high selectivity, and long-term stable operation.

[0004] Therefore, developing new methods to efficiently drive propane dehydrogenation under relatively mild conditions is of great significance for reducing energy consumption in traditional dehydrogenation processes, improving olefin selectivity, and extending catalyst lifetime. Photothermal catalysis utilizes light energy to achieve localized energy input on the catalyst surface, promoting alkane activation and dehydrogenation reactions without completely relying on external high-temperature furnace heating, providing a new technological pathway for the efficient conversion of light alkanes. However, existing photothermal catalytic systems still face problems such as insufficient photothermal conversion efficiency, unstable active site structure, low olefin selectivity, and limited long-term operational stability. Therefore, designing catalysts with high photothermal conversion capacity, excellent dehydrogenation activity, and structural stability, and establishing methods suitable for photothermally driven propane dehydrogenation, has both significant academic value and promising industrial application prospects. Summary of the Invention

[0005] The purpose of this invention is to provide a photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst, along with its catalyst and applications. This method addresses the problems of existing propane dehydrogenation reactions, which typically rely on external high-temperature heating, have high energy consumption, are prone to reduced selectivity for target olefins, are susceptible to catalyst deactivation due to carbon buildup, and suffer from insufficient stability over long periods of operation. This method utilizes a supported high-entropy intermetallic compound catalyst to convert light energy into the energy required for the reaction under illumination. By promoting the activation of propane C–H bonds and the dehydrogenation reaction through localized energy input on the catalyst surface, it achieves efficient and highly selective conversion of propane and hydrogen.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A photothermal-driven propane dehydrogenation method includes: contacting a propane feedstock gas with a supported high-entropy intermetallic compound catalyst under photoluminescence to conduct a dehydrogenation reaction, generating a corresponding olefin and hydrogen; wherein the supported high-entropy intermetallic compound catalyst comprises a support and a high-entropy intermetallic compound supported on the support, the high-entropy intermetallic compound having an ordered intermetallic compound structure. The propane feedstock gas can be pure propane gas or a propane-containing mixture.

[0008] The support is selected from one or more of molecular sieve supports, oxide supports, and composite oxide supports. Preferably, the support is a germanium-doped titanium-silicon molecular sieve, more preferably a Ge-TS-1 molecular sieve. The metal element in the high-entropy intermetallic compound includes at least three of Ru, Rh, Pd, Pt, Ir, Ni, Co, Fe, Cu, Ag, Au, Ga, In, Sn, Zn, Mo, W, and Re. Preferably, the high-entropy intermetallic compound contains Ru, Rh, Pd, In, and Sn. The loading of the high-entropy intermetallic compound is 0.01–30 wt%.

[0009] The illumination intensity under the specified illumination conditions is 10–5000 mW / cm², and the light source is selected from one or more of natural light, xenon lamps, LED lamps, tungsten lamps, mercury lamps, and lasers. The dehydrogenation reaction can be carried out without external electric heating or furnace heating, or under the combined effect of illumination and external auxiliary heating. The external set temperature for the dehydrogenation reaction is 20–600 °C, the reaction pressure is 0.1–10 MPa, and the propane feedstock gas flow rate is 1–100 mL / min.

[0010] Furthermore, under light irradiation, propane undergoes a dehydrogenation reaction to produce propylene and hydrogen, with a propane conversion rate of over 46% and a propylene selectivity of over 99%. The catalyst can operate continuously and stably for approximately 1200 hours, indicating that this method has high reactivity, target product selectivity, and long-term stability.

[0011] The beneficial effects of this invention are as follows:

[0012] First, the present invention utilizes the photothermal conversion capability of a supported high-entropy intermetallic compound catalyst under light conditions to drive the propane dehydrogenation reaction, which can reduce the dependence on traditional external high-temperature heating methods.

[0013] Second, the high-entropy intermetallic compound has an ordered structure, which is beneficial to improving the structural stability and deactivation resistance of the catalyst.

[0014] Third, the method can achieve efficient and highly selective conversion of propane and is suitable for continuous flow reactions;

[0015] Fourth, this method provides a new technical approach for the preparation of high-value olefins from propane dehydrogenation involving solar or light energy.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 A comparison of the catalytic performance of different catalyst systems for photothermal-driven propane dehydrogenation.

[0018] Figure 2 The figure shows the long-term stability test results of the RhRuPdInSn / Ge-TS-1 molecular sieve catalyst for photothermal-driven propane dehydrogenation.

[0019] Figure 3 The graph shows the continuous operation performance of the RhRuPdInSn / Ge-TS-1 molecular sieve catalyst for dehydrogenation reactions of different light alkanes. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Through in-depth research, the inventors have discovered a supported high-entropy intermetallic compound catalyst with strong C–H bond activation ability and high photothermal conversion capacity, which can effectively promote photothermally driven dehydrogenation reactions of light alkanes. The metal components of the high-entropy intermetallic compound include, but are not limited to, Ru, Rh, Pd, Pt, Ir, In, and Sn. Using this supported high-entropy intermetallic compound as a catalyst, highly efficient, highly selective, and highly stable dehydrogenation reactions of light alkanes can be achieved under photoluminescence conditions, for the preparation of corresponding light olefins and hydrogen.

[0025] The photothermal-driven dehydrogenation method for light alkanes provided by this invention includes: placing a supported high-entropy intermetallic compound catalyst in a reactor, introducing a light alkane feed gas into the reactor, and allowing the light alkane to contact the catalyst under light irradiation conditions and undergo a dehydrogenation reaction to generate the corresponding olefin and hydrogen. The light alkane includes one or more of ethane, propane, n-butane, and isobutane; the corresponding olefin includes one or more of ethylene, propylene, n-butene, and isobutene.

[0026] In the method of this invention, the light alkane feed gas can be pure light alkane gas or a mixed gas containing light alkanes. The mixed gas containing light alkanes refers to a gas mixture containing light alkanes, and the remaining components can be inert gases or other gases that do not significantly affect the dehydrogenation reaction. The inert gases include, but are not limited to, He, Ar, and N2. The volume fraction of the light alkanes in the mixed gas can be 1–100%, preferably 5–50%, and more preferably 10%.

[0027] In the method of this invention, the reaction products mainly include corresponding light olefins and hydrogen, and may contain unreacted light alkanes. After the reaction is completed, the reaction results can be analyzed using conventional detection methods, such as using gas chromatography to detect the feed gas conversion rate, olefin formation rate, olefin selectivity, and hydrogen formation. Catalyst stability can be evaluated by continuously operating under set conditions and monitoring changes in conversion rate and selectivity over time.

[0028] In the method of this invention, the supported high-entropy intermetallic compound catalyst includes a support and a high-entropy intermetallic compound supported on the support. The support includes, but is not limited to, Ge-TS-1 molecular sieves, and can also be molecular sieve supports such as TiO2, Al2O3, SiO2, TS-1, and HZSM-5, oxide supports, or composite oxide supports. Preferably, the support is a Ge-TS-1 molecular sieve. The Ge-TS-1 molecular sieve can be commercially available or prepared as needed using conventional molecular sieve synthesis methods. Ge-TS-1 molecular sieves possess good structural stability, thermal stability, and pore confinement effect, which is beneficial for the dispersion and stability of high-entropy intermetallic compounds.

[0029] In the method of this invention, the metal component of the high-entropy intermetallic compound includes, but is not limited to, Ru, Rh, Pd, Pt, Ir, In, Sn, etc., preferably a RuRhPdInSn high-entropy intermetallic compound. The metal precursor used to prepare the catalyst can be one or more of the following: nitrate, chloride, acetate, acetylacetone salt, or other soluble metal salt of the corresponding metal. The high-entropy intermetallic compound can be loaded onto the surface or within the pores of a support by impregnation, deposition, reduction, heat treatment, or other conventional loading methods.

[0030] In the method of the present invention, the loading of the high-entropy intermetallic compound can be 0.01–30 wt%, preferably 0.1–20 wt%, and more preferably 1–10 wt%. In another embodiment, the ratio of the total molar amount of metal elements in the high-entropy intermetallic compound to the total molar amount of Si, Ti, and Ge elements in the Ge-TS-1 molecular sieve can be 0.005–0.1:1, preferably 0.05:1.

[0031] In the method of this invention, there is no particular limitation on the pressure of the light alkane feed gas in the reactor, as long as it meets the requirements for reaction safety and continuous operation. Preferably, the pressure of the light alkane feed gas is 0.1–10 MPa, more preferably 0.1–1 MPa. The flow rate of the light alkane feed gas can be 1–100 mL / min, preferably 5–60 mL / min, more preferably 5 mL / min.

[0032] In the method of the present invention, the light intensity of the illumination conditions can be 10–5000 mW / cm², preferably 1000–5000 mW / cm², and more preferably 4000 mW / cm². The light source used for the illumination conditions is not particularly limited, as long as it can provide light radiation to the catalyst. Preferably, the light source is selected from one or more of focused sunlight, xenon lamps, LED lamps, tungsten lamps, mercury lamps, and lasers.

[0033] In the method of this invention, the dehydrogenation reaction can be carried out without external electric heating or furnace heating, or under the combined effect of light and external auxiliary heating. The external set temperature of the reactor can be 20–600°C, preferably 20–500°C. When the reaction is carried out without external electric heating or furnace heating, the catalyst surface can be locally heated by light illumination, thereby driving the dehydrogenation reaction of light alkanes. When necessary, the reactor can also be assisted by heating wires, heating jackets, or other conventional heating methods to reach the required temperature.

[0034] In the method of this invention, there are no particular limitations on the reactor used, as long as it can meet the requirements for aeration, sealing, pressure resistance, temperature resistance, and photosensitive reaction. The reactor can be a quartz reactor, a glass reactor, a fixed-bed reactor, or a flow-through reactor, preferably a flow-through fixed-bed reactor.

[0035] In one specific embodiment, the light alkane is propane, and the corresponding olefin is propylene. Using a Ge-TS-1 molecular sieve supported on a RuRhPdInSn high-entropy intermetallic compound as a catalyst, the propane dehydrogenation reaction under light irradiation achieves a propane conversion rate of over 46% and a propylene selectivity greater than 99%. The catalyst can operate continuously and stably for approximately 1200 hours, exhibiting excellent reactivity, target product selectivity, and long-term stability.

[0036] The present invention will be further described below with reference to specific embodiments. These embodiments are merely illustrative of some specific implementations of the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, any equivalent substitutions, modifications, or improvements made to the technical solutions of the present invention without departing from the inventive concept should fall within the scope of protection of the present invention. The scope of protection of the present invention is defined by the scope of the claims.

[0037] Unless otherwise stated, the sources of raw materials, reagents and gases used in this invention are not particularly limited and can all be obtained through commercial means; the reaction equipment, light source, detection equipment and auxiliary devices used are also not particularly limited, as long as they can achieve the purpose of photothermal driven dehydrogenation reaction of light alkane and product detection as described in this invention.

[0038] Catalyst preparation

[0039] The catalyst used in this invention can be prepared according to the following method. The following description uses a Ge-TS-1 molecular sieve catalyst supported on a high-entropy intermetallic compound as an example.

[0040] 1 g of Ge-TS-1 molecular sieve was added to a 500 mL glass beaker, followed by 200 mL of deionized water. The mixture was stirred vigorously for 30 min to ensure thorough dispersion of the Ge-TS-1 molecular sieve. Then, a metal precursor solution was added, with each metal precursor solution having a concentration of 10 mM and an addition volume of 10 mL. The metal precursors could be selected from one or more of the nitrate, chloride, acetate, and acetylacetone salts of the corresponding metals. After adding the metal precursors, stirring was continued at room temperature for 1 h. Then, an alkalinity adjuster was added to adjust the pH of the mixture to alkaline, preferably to pH 8–11. The resulting mixture was then sonicated for 30 min to further uniformly disperse the metal precursors on the surface or in the channels of the Ge-TS-1 molecular sieve. After sonication, the mixture was centrifuged, the solid product was collected, and dried in an oven to remove moisture.

[0041] The dried sample was placed in a tube furnace and subjected to reduction heat treatment under a mixed atmosphere of 10% H2 / 90% Ar. The heat treatment temperature was 600 °C, the holding time was 3 h, and the heating rate was 5 °C min⁻¹. After heat treatment, it was naturally cooled to room temperature to obtain the Ge-TS-1 molecular sieve catalyst supported on a high-entropy intermetallic compound. In one specific embodiment, the high-entropy intermetallic compound is a RuRhPdInSn high-entropy intermetallic compound.

[0042] In this embodiment, the ratio of the total molar amount of metal elements in the high-entropy intermetallic compound to the total molar amount of Si, Ti, and Ge elements in the Ge-TS-1 molecular sieve is 0.05:1. Based on the same preparation method described above, by only changing the amount of the added metal precursor, a series of high-entropy intermetallic compound-supported Ge-TS-1 molecular sieve catalysts with a ratio of the total molar amount of metal elements to the total molar amount of Si, Ti, and Ge elements in the Ge-TS-1 molecular sieve of 0.005–0.1:1 can be prepared.

[0043] Based on the same preparation method described above, by simply changing the type of metal precursor used, Ge-TS-1 molecular sieve catalysts supported on high-entropy intermetallic compounds with different compositions can be prepared. These high-entropy intermetallic compounds include, but are not limited to, RuRhPtInSn, RuRhIrInSn, RhPtPdInSn, RhPtIrInSn, and RuRhPdInZn.

[0044] Based on the same preparation method described above, other supports can also be used to replace Ge-TS-1 molecular sieves to prepare supported high-entropy intermetallic compound catalysts. These other supports include, but are not limited to, TiO2, Al2O3, SiO2, TS-1, and HZSM-5. By maintaining the same type and amount of metal precursors, other supported high-entropy intermetallic compound catalysts with the same or similar metal loading can be obtained.

[0045] Example 1

[0046] Photothermal-driven propane dehydrogenation was carried out in a flow-through fixed-bed reactor. The reactor was connected to a gas pipeline via a stainless steel valve, with a pressure limit of 20 MPa. In this embodiment, 100 mg of a high-entropy intermetallic compound-supported Ge-TS-1 molecular sieve catalyst, RhRuPdInSn, was added to the reactor. The ratio of the total molar amount of metal elements in the RhRuPdInSn high-entropy intermetallic compound to the total molar amount of Si, Ti, and Ge elements in the Ge-TS-1 molecular sieve was 0.05:1. A gas cylinder containing 10 vol% C3H8 and 90 vol% Ar was connected to the reactor via a pressure reducing valve and introduced into the reactor. In this embodiment, the reaction pressure was atmospheric pressure, and the total flow rate of the mixed gas was 5 mL min⁻¹. The initial external temperature of the reactor was room temperature, approximately 25 °C. Focused sunlight was used as the light source, and the catalyst bed was irradiated under a light intensity of 4000 mW cm⁻², causing propane to undergo dehydrogenation under the action of the catalyst. The reaction products were analyzed using an online gas chromatograph equipped with two flame ionization detectors and one thermal conductivity detector. Hydrocarbon components were detected by the flame ionization detector, while hydrogen and permanent gases were detected by the thermal conductivity detector. Gas chromatographic analysis showed that the main products of the propane dehydrogenation reaction were propylene and hydrogen. Under the above reaction conditions, the C3H8 conversion rate reached over 58%, and the C3H6 selectivity reached over 99%, indicating that the RhRuPdInSn / Ge-TS-1 catalyst described in this invention possesses high reactivity and target product selectivity in the photothermal-driven propane dehydrogenation reaction.

[0047] Example 2

[0048] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the RhRuPdInSn / TS-1 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 31%, and the selectivity for the target product C3H6 reached over 99%. These results indicate that, in addition to Ge-TS-1 molecular sieves, TS-1 molecular sieves can also serve as supports for high-entropy intermetallic compound catalysts in photothermal-driven propane dehydrogenation reactions.

[0049] Example 3

[0050] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the RhRuPdInSn / HZSM-5 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 3%, and the selectivity for the target product C3H6 was 97%. These results indicate that the HZSM-5 molecular sieve can also serve as a support for high-entropy intermetallic compound catalysts in the photothermal-driven propane dehydrogenation reaction, but its reactivity is lower than that of the RhRuPdInSn / Ge-TS-1 catalyst.

[0051] Example 4

[0052] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that a RhRuPdInSn / TiO2 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 6%, and the selectivity for the target product C3H6 was 92%. These results indicate that TiO2 can serve as a support for high-entropy intermetallic compound catalysts in the photothermal-driven propane dehydrogenation reaction.

[0053] Example 5

[0054] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that a RhRuPdInSn / Al2O3 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 6%, and the selectivity for the target product C3H6 was 92%. These results indicate that Al2O3 can serve as a support for high-entropy intermetallic compound catalysts in the photothermal-driven propane dehydrogenation reaction.

[0055] Example 6

[0056] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that a RhRuPdInSn / SiO2 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 5%, and the selectivity for the target product C3H6 was 92%. These results indicate that SiO2 can serve as a support for high-entropy intermetallic compound catalysts in the photothermal-driven propane dehydrogenation reaction.

[0057] Example 7

[0058] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that a 300 W xenon lamp was used instead of focused sunlight as the light source to irradiate the catalyst bed. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 43%, and the selectivity for the target product C3H6 was 99.5%. This result indicates that, in addition to focused sunlight, a xenon lamp can also be used as a light source to drive the light alkane dehydrogenation reaction described in this invention.

[0059] Example 8

[0060] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the light intensity was adjusted to 3000 mW cm⁻². Online gas chromatography analysis showed that the C3H8 conversion rate reached over 44%, and the selectivity for the target product C3H6 reached over 99%. These results demonstrate that changing the light intensity can modulate the reactivity of the photothermal-driven propane dehydrogenation reaction described in this invention.

[0061] Example 9

[0062] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the light intensity was adjusted to 5000 mW cm⁻². Online gas chromatography analysis showed that the C3H8 conversion rate reached over 62%, and the selectivity for the target product C3H6 reached over 98%. These results demonstrate that changing the light intensity can modulate the reactivity of the photothermal-driven propane dehydrogenation reaction described in this invention.

[0063] Example 10

[0064] The photothermal-driven dehydrogenation of light alkanes was carried out using the same reaction process and detection method as in Example 1, except that a mixed gas of 10 vol% C2H6 and 90 vol% Ar was used instead of the mixed gas of 10 vol% C3H8 and 90 vol% Ar in Example 1 as the feed gas. Online gas chromatography analysis showed that the C2H6 conversion rate was 34%, and the selectivity for the target product C2H4 was 99%. This result indicates that the method described in this invention is also applicable to the photothermal-driven dehydrogenation of ethane to produce ethylene.

[0065] Example 11

[0066] The photothermal-driven dehydrogenation reaction of light alkane was carried out according to the same reaction process and detection method as in Example 1, except that: in this example, 10 vol% C4H was used. 10A mixture of 90 vol% Ar and C3H8 was used as the feed gas instead of the 10 vol% C3H8 and 90 vol% Ar mixture in Example 1, and the light intensity was adjusted to 2000 mW cm⁻². Online gas chromatography analysis revealed that C4H8... 10 The conversion rate was 36%, and the selectivity for the target product C4H8 was 95%. These results indicate that the method described in this invention can be used for photothermal-driven dehydrogenation of butane to prepare butene.

[0067] Example 12

[0068] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the RhRuPdInSn / Ge-TS-1 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 35%, and the selectivity for the target product C3H6 reached over 98%. These results indicate that, even after changing the metal composition of the high-entropy intermetallic compound, the resulting supported high-entropy intermetallic compound catalyst can still be used for photothermal-driven propane dehydrogenation.

[0069] Example 13

[0070] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the RhRuPdInSn / Ge-TS-1 catalyst was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1. Online gas chromatography analysis showed that the C3H8 conversion rate reached over 35%, and the selectivity for the target product C3H6 reached over 97%. These results indicate that Ir-containing high-entropy intermetallic compound supported catalysts can also be used for photothermal-driven propane dehydrogenation reactions.

[0071] Example 14

[0072] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that the RhRuPdInSn / Ge-TS-1 catalyst was subjected to a long-term stability test under a light intensity of 3000 mW cm⁻². The results showed that after 1200 h of continuous operation, the C3H8 conversion and C3H6 selectivity of the catalyst did not decrease significantly, indicating that the catalyst of this invention has good long-term operational stability in the photothermal-driven propane dehydrogenation reaction.

[0073] Comparative Example 1:

[0074] The propane dehydrogenation reaction was carried out using the same reaction procedure and detection method as in Example 1, except that no light was applied in this comparative example, the initial external temperature of the reactor was maintained at room temperature (approximately 25 °C), and all other reaction conditions remained unchanged. Online gas chromatography detection showed no significant formation of C3H6 and no effective conversion of C3H8 under the light-free conditions. This result indicates that, under the reaction conditions described in this invention, light is an important energy input for driving the propane dehydrogenation reaction.

[0075] Comparative Example 2

[0076] The propane dehydrogenation reaction was carried out using the same reaction process and detection method as in Example 1, except that no catalyst was added to the reactor in this comparative example, while all other reaction conditions remained unchanged. Online gas chromatography detection showed no significant formation of C3H6 and no effective conversion of C3H8 under catalyst-free conditions. This result indicates that light irradiation alone is insufficient to effectively drive the propane dehydrogenation reaction, and the supported high-entropy intermetallic compound catalyst described in this invention plays a crucial role in achieving photothermal-driven propane dehydrogenation.

[0077] Comparative Example 3:

[0078] The photothermal-driven propane dehydrogenation reaction was carried out using the same reaction procedure and detection method as in Example 1, except that a Ge-TS-1 molecular sieve without high-entropy intermetallic compounds was used instead of the RhRuPdInSn / Ge-TS-1 catalyst in Example 1, while the other reaction conditions remained unchanged. Online gas chromatography analysis showed that no significant C3H6 formation was detected when using the Ge-TS-1 molecular sieve alone, and C3H8 did not undergo effective conversion. These results indicate that the Ge-TS-1 molecular sieve support itself is not the main source of activity in the propane dehydrogenation reaction; its main role is to disperse, stabilize, and regulate the high-entropy intermetallic compounds. The high-entropy intermetallic compounds supported on the Ge-TS-1 molecular sieve are the key active components for achieving efficient photothermal-driven propane dehydrogenation.

[0079] Figure 1 middle, Figure 1 a represents the comparison results of C3H6 yield and C3H6 selectivity for catalysts with different metal components; Figure 1 b shows the comparison of C3H6 yield and C3H6 selectivity for RhRuPdInSn high-entropy intermetallic compound catalysts supported on different supports.

[0080] Figure 2 The changes in C3H8 conversion and C3H6 selectivity with reaction time are shown.

[0081] Figure 3 middle, Figure 3a represents the changes in C2H6 conversion and C2H4 selectivity with reaction time in the ethane dehydrogenation reaction; Figure 3 b represents the n-C4H in the dehydrogenation reaction of n-butane. 10 The conversion rate and C4H8 selectivity change with reaction time.

[0082] In summary, this invention provides a photothermal catalytic method for propane dehydrogenation using a highly stable supported high-entropy intermetallic compound catalyst, along with its catalyst and applications. This method utilizes the photothermal conversion capability of the supported high-entropy intermetallic compound catalyst under illumination to drive the dehydrogenation reaction of light alkanes, reducing dependence on traditional external high-temperature heating methods. The high-entropy intermetallic compound possesses an ordered intermetallic compound structure, which is beneficial for improving the structural stability and deactivation resistance of the catalyst. The method can achieve efficient and highly selective conversion of light alkanes to corresponding olefins and is suitable for continuous flow reactions. This method provides a new technical approach for the dehydrogenation of light alkanes using solar or light energy to produce high-value olefins.

[0083] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A photothermal catalytic method for propane dehydrogenation using a highly stable supported high-entropy intermetallic compound catalyst, characterized in that, The method includes: under light irradiation, contacting propane gas with a supported high-entropy intermetallic compound catalyst to carry out a dehydrogenation reaction, producing propylene and hydrogen; wherein the supported high-entropy intermetallic compound catalyst includes a support and a high-entropy intermetallic compound supported on the support, the support being selected from one or more of molecular sieve supports, oxide supports, and composite oxide supports, and the high-entropy intermetallic compound containing at least three metal elements and having an ordered intermetallic compound structure. The raw material gas for the propane gas is pure propane gas or a mixed gas containing propylene.

2. The photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst as described in claim 1, characterized in that... The propane-containing gas mixture also includes an inert gas, which is selected from one or more of helium, argon, and nitrogen. The molecular sieve support is selected from one or more of the following: germanium-doped titanium-silicon molecular sieves, titanium-silicon molecular sieves, silica-alumina molecular sieves, pure silica molecular sieves, ZSM-5, HZSM-5, TS-1, Ge-TS-1, Silicalite-1, and Beta molecular sieves. The oxide support or composite oxide support is selected from one or more of SiO2, Al2O3, TiO2, ZrO2, CeO2, MgO, SiO2-Al2O3, TiO2-SiO2, and ZrO2-SiO2. The metal element in the high-entropy intermetallic compound is selected from at least three of Ru, Rh, Pd, Pt, Ir, Ni, Co, Fe, Cu, Ag, Au, Ga, In, Sn, Zn, Mo, W, and Re. The dehydrogenation reaction is carried out without external electric heating or furnace heating, and the light irradiation condition is the main energy input method to drive the dehydrogenation reaction.

3. A photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst as described in claim 1 or 2, characterized in that, The carrier is preferably a Ge-TS-1 molecular sieve. The high-entropy intermetallic compound contains five metallic elements: Ru, Rh, Pd, In, and Sn. The arrangement of metal elements in the high-entropy intermetallic compound includes, but is limited to, an arrangement in the form of an ordered intermetallic compound crystalline phase; The loading of the high-entropy intermetallic compound is 0.01–30 wt%. The high-entropy intermetallic compound has a particle size of 0.5–100 nm. The light intensity under the specified lighting conditions is 10–5000 mW / cm². The light source for the illumination conditions is selected from one or more of natural light, xenon lamps, LED lamps, tungsten lamps, mercury lamps, and lasers.

4. The photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst as described in claim 3, characterized in that, The loading of the high-entropy intermetallic compound is preferably 0.1–20 wt%. The particle size of the high-entropy intermetallic compound is preferably 1–50 nm.

5. The photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst as described in claim 4, characterized in that, The loading of the high-entropy intermetallic compound is further preferably 1–10 wt%. The particle size of the high-entropy intermetallic compound is further preferably 1–20 nm.

6. The photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst as described in claim 1, characterized in that, The dehydrogenation reaction is carried out under light irradiation and external auxiliary heating, with the external auxiliary heating set at a temperature of 20–600 °C. The flow rate of the propane gas feedstock is 1–100 mL / min. The pressure of the dehydrogenation reaction is 0.1–10 MPa. The dehydrogenation reaction is carried out in a quartz reactor, glass reactor, fixed-bed reactor, or flow reactor. The dehydrogenation reaction can be run continuously for 1–1200 h.

7. The photothermal catalytic propane dehydrogenation method using a highly stable supported high-entropy intermetallic compound catalyst as described in claim 6, characterized in that, The preferred flow rate of the propane gas feedstock is 5–60 mL / min. The pressure for the dehydrogenation reaction is preferably 0.1–1 MPa.

8. A catalyst using a highly stable supported high-entropy intermetallic compound, characterized in that, The catalyst includes a support and a high-entropy intermetallic compound supported on the support. The support is selected from one or more of molecular sieve supports, oxide supports, and composite oxide supports. The high-entropy intermetallic compound contains at least three metal elements and has an ordered structure of intermetallic compounds.

9. The highly stable supported high-entropy intermetallic compound catalyst as described in claim 8, characterized in that, The carrier is a germanium-doped titanium-silicon molecular sieve, preferably a Ge-TS-1 molecular sieve; the high-entropy intermetallic compound contains five metal elements: Ru, Rh, Pd, In, and Sn.

10. The application of the catalyst as described in claim 8 or 9 in the photothermal-driven propane dehydrogenation reaction.

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