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CN-122006706-A - Propane dehydrogenation catalyst suitable for in-situ Joule heating and preparation method and application thereof

CN122006706ACN 122006706 ACN122006706 ACN 122006706ACN-122006706-A

Abstract

The invention belongs to the technical field of catalysts, and particularly discloses a propane dehydrogenation catalyst suitable for In-situ Joule heating, a preparation method and application thereof, wherein the catalyst comprises a conductive foam substrate and a catalytic layer coated on the substrate, the catalytic layer contains a complex metal oxide support Mg (M) (Al) O and an active center intermetallic compound PtM dispersed on the support, M In the support and active center being Zn, in, ga or Y. The preparation method comprises the following steps of 1) preparing hydrotalcite precursor MgAlM-LDHs, impregnating and loading Pt precursor solution on the hydrotalcite precursor to obtain a precursor of a catalytic layer, 2) coating precursor slurry of the catalytic layer on a substrate to obtain a precursor of a catalyst, and 3) roasting and reducing the precursor of the catalyst to obtain the catalyst. The catalyst of the invention maintains high propylene selectivity and activity in the Joule heating propane dehydrogenation reaction, and can improve propylene yield.

Inventors

  • HE JING
  • ZHU YANRU
  • Zhuang Najie
  • AN ZHE
  • ZHANG JIAN
  • SHU XIN

Assignees

  • 北京化工大学
  • 衢州资源化工创新研究院

Dates

Publication Date
20260512
Application Date
20260114

Claims (10)

  1. 1. Propane dehydrogenation catalyst suitable for In situ joule heating, characterized In that it comprises a conductive foam substrate and a catalytic layer coated on the substrate, said catalytic layer comprising a complex metal oxide support Mg (M) (Al) O and an active center intermetallic compound PtM dispersed on the support, M In the support and active center being Zn, in, ga or Y.
  2. 2. The propane dehydrogenation catalyst suitable for in situ joule heating as in claim 1, wherein the substrate is foamed silicon carbide, foamed carbon, foamed copper or foamed aluminum and the substrate has a porosity of 30-120 ppi.
  3. 3. Propane dehydrogenation catalyst suitable for in situ joule heating according to claim 1, wherein the Pt content is from 0.1 to 0.5wt% and the M content is from 0.1 to 10wt%, based on the total weight of the catalyst.
  4. 4. Propane dehydrogenation catalyst suitable for in situ joule heating according to claim 1, wherein the particle size of the intermetallic PtM is 0.5-3nm.
  5. 5. A process for the preparation of a propane dehydrogenation catalyst suitable for in situ joule heating as defined in any of claims 1-4, characterized in that the preparation process comprises the steps of: 1) Preparing hydrotalcite precursor MgAlM-LDHs, and impregnating and loading Pt precursor solution on the hydrotalcite precursor to obtain a precursor of a catalytic layer; 2) Coating the precursor slurry of the catalytic layer on a substrate to obtain a precursor of the catalyst; 3) And roasting and reducing the precursor of the catalyst to obtain the catalyst.
  6. 6. The method for preparing a propane dehydrogenation catalyst suitable for in-situ joule heating as set forth in claim 5, wherein in step 1), the Pt precursor solution is loaded by an incipient wetness impregnation method, uniformly vibrated during the impregnation process, and then dried at 100-130 ℃ for 1-5 hours to obtain a precursor of the catalytic layer.
  7. 7. The method for preparing a propane dehydrogenation catalyst suitable for in-situ joule heating as set forth in claim 5, wherein in step 2), the coating is performed by a spin coating method, the precursor slurry of the catalytic layer is dropped onto the surface of the substrate in a state where the substrate is rotated to form a thin film layer, and the precursor of the catalyst is dried.
  8. 8. The method for preparing a propane dehydrogenation catalyst suitable for in-situ joule heating as set forth in claim 5, wherein the condition of calcination comprises calcination at 600-800 ℃ in an atmosphere of N 2 for 2-4 hours at a temperature-raising rate of 1-10 ℃ per minute and a flow rate of N 2 of 10-60mL per minute.
  9. 9. The method for preparing a propane dehydrogenation catalyst suitable for in-situ joule heating as set forth in claim 5, wherein the conditions of the reduction treatment comprise reduction in an atmosphere of H 2 at 600-800 ℃ for 2-4 hours at a flow rate of H 2 of 10-60mL/min.
  10. 10. The use of a propane dehydrogenation catalyst suitable for in situ joule heating in the production of propylene by propane dehydrogenation according to any of claims 1-4, characterized in that the propane dehydrogenation is powered by in situ joule heating, preferably at a reaction temperature of 300-550 ℃ and at atmospheric pressure.

Description

Propane dehydrogenation catalyst suitable for in-situ Joule heating and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to a propane dehydrogenation catalyst suitable for in-situ Joule heating and a preparation method thereof, and application of the catalyst in preparing propylene by propane dehydrogenation. Background Strong endothermic reactions are widely used in many important chemical processes. In strong endothermic reactions such as dehydrogenation of low-carbon alkanes, dry reforming of methane, etc., continuous and timely energy supply is required to maintain high-temperature reaction conditions, thereby realizing conversion rate with economic feasibility. Therefore, the energy supply efficiency plays a key role in ensuring the reaction efficiency. The traditional heating generally utilizes the heat generated by burning fossil fuel to heat the reactor, and the heat is firstly transmitted to the internal catalyst bed layer step by means of radiation, conduction and the like, so that the inherent defects of heat transmission delay, large temperature gradient, low energy utilization rate and the like exist, and the efficient performance of the strong endothermic reaction is severely restricted. Therefore, how to timely supply energy to the active site of the strong endothermic reaction so as to solve the heat transfer bottleneck in the strong endothermic reaction and improve the reaction energy efficiency becomes a key difficult problem to overcome in the current chemical industry. In recent years, novel heating systems such as in-situ resistance heating, microwave heating, electromagnetic induction heating, photo-thermal synergy and the like are widely reported, and a new idea is provided for supplying energy for strong endothermic reaction. The in-situ resistance heating technology can directly supply energy to the catalyst, and has the advantages of accurate heat supply, low energy consumption, quick temperature response and the like, and is widely focused. In addition, in the in-situ resistance heating process, electric field effect is synchronously introduced when current flows through the catalyst, and catalytic reaction performance and action mechanism are affected. At present, researchers have conducted a great deal of research about the performance enhancement mechanism of in-situ resistance heating on strong endothermic reactions, and have revealed that the reaction performance can be enhanced by increasing the heating rate, changing the adsorption and desorption strength of reactants/products, promoting the jump of surface protons, regulating and controlling surface oxygen species, and the like. However, it is a central research challenge in this field at present as to how to construct an adapted in-situ resistance heating system. Disclosure of Invention In view of the above, the inventors of the present invention have found that the main direction of catalytic activity of the catalyst can be improved by adjusting the resistance, pore structure, and metal-carrier interaction of the base material as a means of controlling the thermal field and electric field. Based on this, the object of the present invention is to provide a propane dehydrogenation catalyst suitable for in situ joule heating, which shows high activity and excellent propylene selectivity in situ joule heated catalyzed propane dehydrogenation reactions, and which gives high propylene yields with low energy consumption, as well as a process for its preparation and its use. In a first aspect the present invention provides a propane dehydrogenation catalyst suitable for In situ joule heating comprising a conductive foam substrate and a catalytic layer coated on the substrate, said catalytic layer comprising a complex metal oxide support Mg (M) (Al) O and an active center intermetallic compound PtM dispersed on the support, M In the support and active center being Zn, in, ga or Y. In a second aspect, the present invention provides a process for the preparation of a propane dehydrogenation catalyst suitable for in situ joule heating as described above, comprising the steps of: 1) Preparing hydrotalcite precursor MgAlM-LDHs, and impregnating and loading Pt precursor solution on the hydrotalcite precursor to obtain a precursor of a catalytic layer; 2) Coating the precursor slurry of the catalytic layer on a substrate to obtain a precursor of the catalyst; 3) And roasting and reducing the precursor of the catalyst to obtain the catalyst. The third aspect of the invention provides the use of a propane dehydrogenation catalyst suitable for in situ joule heating as described above in the production of propylene by dehydrogenation of propane in the manner of in situ joule heating. Compared with the prior art, the invention has the following beneficial effects: in the catalyst, the foam substrate has the characteristics of a semiconductor/conduct