Metal carrier load gold catalyst and application thereof in preparing aldehyde or ketone by selectively oxidizing catalytic alcohol

Abstract

The invention discloses a metal carrier load gold catalyst and application thereof in preparing aldehyde or ketone by selectively oxidizing catalytic alcohol, wherein the catalyst is prepared by isopyknically impregnating a metal fiber or metal particle carriers with chloroauric acid or sodium chloraurate solution and baking for 2 hours at a temperature between 250 DEG C and 400 DEG C, and containing 0.5-6.0 percent of gold and 94.0-99.5 percent of carrier; in the process of preparing the aldehyde or the ketone by vapor phase selective oxydehydrogenation of the catalytic alcohol, the catalystadopts a fixed bed reaction device, takes oxygen or air as an oxidant and selectively oxidizes the alcohol to generate aldehyde or ketone under the conditions that the reaction temperature is 250-350DEG C, the weight hourly space velocity of the alcohol is 10-60<-1> hours and the mole ratio of O2 to hydroxyl group is 0.4-1.2. The catalyst has favorable heat conductivity, high low-temperature activity, good stability, low cost, high efficiency for the catalytic alcohol to prepare the aldehyde or the ketone by selective oxydehydrogenation, and environment friendliness.

Description

technical field [0001] The invention belongs to the technical field of catalysis, and in particular relates to a metal-supported gold catalyst and the application of the catalyst in the preparation of aldehydes or ketones by catalyzing alcohol gas-phase selective oxidation dehydrogenation. technical background [0002] Gold has always been considered as a chemically inert metal. Compared with other noble metals such as platinum and palladium, the catalytic potential of gold has not attracted enough attention. In the 1980s, Japanese scientist Haruta and British scientist Hutchings and others discovered that gold nanoparticles [Nature, 2005, 437, 1098] have extraordinary catalytic effects. At present, Au catalysts are used in low-temperature oxidation of CO, selective hydrogenation, NO x Revert to generate N 2 It exhibits excellent catalytic performance in reactions such as selective oxidative dehydrogenation of alcohols. It not only has mild reaction conditions, high activi...

AI Technical Summary

Problems solved by technology

The electrolytic silver catalyst commonly used in industry has high cost, harsh reaction temperature, low catalytic activity when it is lower than 550°C, and more by-products will be produced when it is higher than 550°C, and silver crystallites are easy to quickly agglomerate under high temperature conditions, resulting in catalytic activity. And the decrease of selectivity and the increase of reaction bed resistance

However, for multi-carbon alcohols (such as benzyl alcohol, etc.), electrolytic silver catalysts are not suitable because high-temperature reactions will obviously lead to pyrolysis and excessive oxidation of reactants and products.

[0004] Oxidation-supported silver catalysts catalyze the oxidative dehydrogenation of alcohols to generate corresponding aldehydes and ketones. The supported silver catalysts reported in U.S. Patent (US 1,067,665) are simple to prepare and have high silver loadings, but the specific area of ​​the catalyst is small, Uneven distribution, less than ideal activity

Chinese patent (CN1262348C) adopts sol-gel method to prepare a kind of supported silver catalyst for methanol dehydrogenation to produce anhydrous formaldehyde, is about a certain amount of ethyl orthosilicate and the aqueous solution containing soluble zinc salt and aluminum salt or alcohol After the solution is mixed, it is added dropwise into the aqueous solution of inorganic silver salt, and it is prepared through the steps of gelling, aging, drying and roasting, but the preparation process is cumbersome, and there are more CO in the by-product

CN101385972 and Catal.Commun.2009,10,1376 disclose a metal microfiber supported silver catalyst and its application, compared with the electrolytic silver catalyst, the reaction of the metal fiber supported silver catalyst to the gas phase selective oxidative dehydrogenation of polycarbonic alcohols The temperature is obviously lowered, and the conversion rate and selectivity are obviously improved, but it is still not ideal

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