Method for preparing supported metal catalyst with high dispersion active center

Abstract

The invention discloses a method for preparing a supported metal catalyst with a high dispersion active center. An improved impregnation method is adopted, i.e. a catalyst conventional carrier is impregnated in a polyfunctional compound comprising more than two hydroxy-philic functional groups after being subjected to drying preprocessing and then is impregnated in aqueous solution of metal salt after being dried; or, a carrier which is not subjected to surface modification is directly impregnated in aqueous solution of metal salt of the polyfunctional compound comprising more than two hydroxy-philic functional groups; and then the metal supported catalyst by drying and calcination. By the improved impregnation method, i.e. a complexation impregnation method, effects of the carrier and the active center can be improved; the use amount of the polyfunctional compound is small and is easy to control; the preparation technical process is simple and reliable; the method disclosed by the invention is a novel approach for preparing a high-efficiency catalyst; and according to the catalyst prepared by the complexation impregnation method, metal active components are uniformly distributed on the surface of the catalyst, the dispersity is improved, the particle size of the active components can be controlled in the range of 10nm, and the particle size distribution is adjustable.

Description

Technical field: [0001] The invention belongs to the technical field of catalysts, and in particular relates to a preparation method of a loaded metal catalyst with highly dispersed active centers. Background technique: [0002] Supported catalysts are commonly used catalysts in the chemical industry, and the metal active components can be uniformly dispersed on the surface of the catalyst. Supported catalysts generally use less metal, and the preparation process is simple and easy to control. Common methods for preparing supported catalysts include impregnation, ion exchange, sol-gel and co-precipitation. In order to prepare catalysts with higher dispersion and higher activity, new preparation methods are constantly emerging. For example: use cold / hot plasma to prepare ultra-fine particle catalysts, and plasma sputtering to assist the deposition of catalyst active components to prepare highly dispersed and highly active catalysts. However, special plasma devices are requi...

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Problems solved by technology

The prepared catalyst has high uniformity, the reaction process is simple and easy to control, the catalyst has high dispersion, high specific surface area and good pore size, the reaction temperature is low during the preparation process, and the crystal form and particle size of nanoparticles are controllable; however, it is widely used in practical applications Metal-organic compound or organic gelling agent, catalyst production cost is higher (Angewandte Chemie Volume35(1996), 1420-1436 and Catalysis Today Volume137(2008), 132-143); Philippe Serp et al. (Chemical Reviews Volume102(2002), 3085 -3128) reviewed the preparation of supported catalysts by chemical vapor deposition (i.e., gas phase impregnation-decomposition method). The metal active precursor was vaporized and then deposited on the carrier, and finally heated and roasted to decompose. Compared with the conventional impregnation method, the metal active component The distribution is more uniform and the activity is much improved, but the metal prerequisite requires easy vaporization and decomposition

The metal precursors commonly used in the actual process are metal carbonyl compounds. Due to their high toxicity, anhydrous and oxygen-free preparation conditions are required, which is not conducive to large-scale application.

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