A kind of silver-supported silver catalyst and its preparation method and application

Abstract

The invention belongs to the technical field of a catalyst, and particularly relates to a silver catalyst containing silver, and a preparation method and application thereof. Electrolytic silver prepared by an electrolytic process is adopted, and high-temperature treatment is carried out under existence of vapor, so that the electrolytic silver generates crystal face reconstruction, and the surface becomes coarse and irregular from a smooth state; a silver salt is loaded to the electrolytic silver after thermal treatment by an isometric steeping method; the silver catalyst containing silver loaded with silver microcrystal on the electrolytic silver is prepared in manners of baking and roasting. The catalyst contains 1-10%(wt) of silver microcrystal. The silver catalyst containing silver can be applied to catalytic oxidation of fatty alcohol or aromatic alcohol, so as to generate corresponding aldehyde or ketone in one step. Compared with the existing silver catalyst containing silver for industrial application, the catalyst is high in low-temperature activity, and good in selectivity, and the service life is obviously prolonged.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a silver-loaded silver catalyst and its preparation method and application. Background technique [0002] Electrolytic silver has been used as a catalyst for the synthesis of corresponding aldehydes or ketones by gas-phase oxidation of alcohols for many years. At present, electrolytic silver catalysts are used in the production of formaldehyde by air oxidation of methanol and the synthesis of glyoxal by air oxidation of ethylene glycol. The electrolytic silver catalyst can be purchased directly from the market, and can also be easily prepared by electrolysis. For example, U.S. Patent No. 5,135,624 describes silver nitrate of 5 to 100 g / L as the electrolyte, pH 1 to 4, and electrolysis temperature 10 to 80 ℃, the current density is 100~3000A / m 2 A method for preparing an electrocrystallized silver catalyst under conditions; German patent DE 2,129,776 describes a cur...

AI Technical Summary

Problems solved by technology

First of all, the alcohol gas phase oxidation reaction is a strong exothermic reaction, which requires good thermal conductivity of the catalyst. The thermal conductivity of the electrolytic silver catalyst is very good, and the thermal conductivity of the loaded silver is much worse; secondly, the silver catalyst needs to be regenerated. For electrolytic silver, It can be regenerated by simple electrolysis without pollution, while the supported catalyst is much more difficult to regenerate because it contains a carrier, resulting in significant cost pressure and environmental pressure