Supported PtZn intermetallic alloy catalyst, method for preparing the same and application thereof

Patent metadata

Field	Value
Publication number	US-11498058-B2
Application number	US-201917260559-A
Country	US
Kind code	B2
Filing date	Nov 21, 2019
Priority date	Jan 8, 2019
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

The present application discloses a supported PtZn intermetallic alloy catalyst, a method for preparing the same and application thereof. The catalyst uses SiO2 as a support and Zn as a promoter, and a small amount of active component Pt is supported; the weight percentage of Pt is 0.025%-1%, and the weight percentage of Zn is 0.025%-1.7%, a co-impregnation method is adopted in preparation, the SiO2 support is impregnated in aqueous solution of chloroplatinic acid and zinc nitrate, and then drying and high-temperature reduction are performed to obtain a PtZn/SiO2 catalyst. The catalyst has the advantages of high activity, high stability, low price and low toxicity. The catalyst provided by the present application is applicable to preparation of alkene through short-chain alkane dehydrogenation, in particular to preparation of propylene through propane dehydrogenation in a hydrogen atmosphere. Under high-temperature conditions, the dehydrogenation activity is very high, the propylene selectivity can reach more than 90%, the stability is good, and the amount of used Pt is small, the utilization rate is high, and it is cheaper than industrial Pt series catalysts.

First claim

What is claimed is:

1. A process for the dehydrogenation of an alkane to prepare an alkene, comprising reacting the alkane in the presence of a supported PtZn intermetallic alloy catalyst to produce the alkene, wherein the alkane comprises ethane, propane, and/or butane; wherein the supported PtZn intermetallic alloy catalyst comprises Pt as an active component and Zn as a promoter; wherein said Pt and Zn are supported on a support and form an atomically ordered intermetallic alloy; and wherein, based on the weight of the support in the catalyst, the weight percentage of Pt is no more than 1 wt %, and the weight percentage of Zn is no more than 1.7 wt %.

2. The process according to claim 1 , wherein the alkene is propylene and the alkane is propane; and wherein the dehydrogenation of the alkane is carried out according to the following steps:
tableting the supported PtZn intermetallic alloy catalyst into a granular catalyst with a mesh size of 20-40 meshes;
putting the obtained granular catalyst into a fixed bed reactor, feeding with nitrogen, and then heating the temperature to a pretreatment temperature of 500-700° C.;
performing pretreatment with hydrogen, maintaining the temperature at the pretreatment temperature for 0.5h-1h, and then tuning the temperature to a reaction temperature of 500-650° C.; and
performing reaction with a reaction gas comprising propane and hydrogen;
wherein the molar ratio of hydrogen to propane is (0-2): 1 , nitrogen is an equilibrium gas, the total gas amount is kept unchanged, and the reaction space velocity based on propane is 1-5h −1 .

3. The process according to claim 1 , wherein the weight percentage of Pt is 0.025 wt %-1 wt %.

4. The process according to claim 1 , wherein the weight percentage of Zn is 0.025 wt %-1.5 wt %.

5. The process according to claim 1 , wherein the support is one selected from the group consisting of silicon dioxide, molecular sieve, zeolite, and aluminum oxide.

Assignees

• Univ Tianjin

Inventors

• Gong Jinlong
• Chen Sai
• Zeng Liang

Classifications

• C07C2523/60

  with zinc, cadmium or mercury · CPC title

• B01J37/0063

  Granulating · CPC title

• C07C5/3337

  of the platinum group · CPC title

• B01J8/0285

  Heating or cooling the reactor (for tubular reactors in furnaces B01J8/062) · CPC title

• B01J37/0201

  Impregnation · CPC title