Method for improving catalyst activity and selectivity based on atomic layer deposition directional regulation

Abstract

Belonging to the technical field related to preparation of metal oxide catalysts, the invention discloses a method for improving the catalyst activity and selectivity based on atomic layer depositiondirectional regulation. The method includes: growing and distributing noble metal nanoparticles uniformly on the surface of a reaction carrier to obtain a noble metal loaded catalyst sample; and depositing a metal oxide assistant on the surface of the noble metal loaded catalyst sample by atomic layer deposition reaction method to obtain a needed catalyst product, and making targeted design to thespecific process parameters of the atomic layer deposition reaction at the same time. The method provided by the invention can enable the oxide assistant to carry out selective deposition on a plurality of crystal planes of the active metal surface, realizes incontinuous coating at special position, at the same time effectively improves the activity and selectivity of the catalyst, and consequently is especially suitable for the application occasion of preparing a catalyst for preparation of a C<2+> oxygenated compound from synthesis gas.

Description

technical field [0001] The invention belongs to the technical field related to the preparation of metal oxide catalysts, and more specifically relates to a method for improving catalyst activity and selectivity based on atomic layer deposition directional control. Background technique [0002] With global warming, the depletion of fossil fuels and the rise in crude oil prices, people are paying more and more attention to the development of clean energy that can replace fossil fuels. Among them, the preparation of clean fuels by gas-phase catalytic reactions is currently the most important industrial production direction, such as synthetic gas ( CO+H 2 ) can directly catalyze the synthesis of C2+ oxygenates, not only as a clean fuel, but also as gasoline additives, etc., and thus has received widespread attention. [0003] For this type of gas-phase catalytic directional synthesis of clean fuels, the main challenge is to develop a related catalyst with excellent catalytic ac...

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Problems solved by technology

[0004] However, further studies have shown that the above-mentioned existing technologies are often unable to effectively improve the two indicators of catalyst activity and selectivity at the same time. At the same time, there are cumbersome operations, poor controllability, and difficulty in adapting to the specificity of the target product required for catalytic directional synthesis. Technical issues such as requirements

Although some active metals and auxiliary agents have also been proposed in the prior art to prepare catalysts (such as Rh-Mn / SiO used in the synthesis of C2+ oxygenates 2 Catalyst), wherein the dispersion and chemical properties of the active metal can be further improved by adding promoters and supports, and the yield of the target product can be improved, but in practice it is found that there are still insufficient active sites at the active metal-promoter interface , and the inability to achieve non-continuous specific packages, etc.

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