Preparation method of high-activity and free-reduction Cu/ZnO catalyst

Abstract

The invention discloses a preparation method of a high-activity and free-reduction Cu / ZnO catalyst and relates to a preparation method of a catalyst. According to the preparation method, acetic anhydride is adopted for replacing original multi-carboxyl organic acid (such as citric acid, glycine and oxalic acid) or formic acid as a chelating agent and a reducing agent; in the stirring process after an alcohol solution with different moles of acetic anhydride is mixed with copper nitrate and zinc nitrate, small bubbles are generated in the solution slowly and are released slowly, brown-yellow oxynitride is released, and then sky-blue uniform precipitates are obtained; after the precipitates are roasted in an inert atmosphere at the temperature of 300 DEG C, the deep-red ultrafine metal Cu / ZnO catalyst can be directly obtained by one step. The Cu / ZnO catalyst is directly used for a synthetic reaction of methanol without any additional reducing process, and is excellent in reaction activity and methanol selectivity.

Description

technical field [0001] The invention relates to a catalyst preparation method, in particular to a high-activity, reduction-free Cu / ZnO catalyst preparation method. Background technique [0002] Metal catalysts are the most important class of catalysts in industrial catalysis, and they are also the most widely used catalysts. According to their functional classification, metal catalysts can be divided into functional catalysts such as hydrogenation, dehydrogenation, oxidation, isomerization, and cyclization. According to its own output and price classification, metal catalysts include base metal catalysts, such as: Ni, Cu, Co, Fe, etc.; and noble metal catalysts, such as: Pt, Pd, Ru, Rh, etc. At present, the preparation methods of metal catalysts mainly include chemical methods and physical methods. Among them, chemical methods mainly include impregnation method, co-precipitation method, homogeneous deposition method, sol-gel method and microemulsion method; physical metho...

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Problems solved by technology

With the deepening of research later, it was found that this method has two disadvantages: ①The combustion process is too violent, and a large amount of heat is released instantaneously, which easily leads to the growth of the reduced metal Cu grains; ②Because it is carried out under an inert atmosphere, many Carboxyl organic matter is incompletely decomposed, and there is a large amount of carbon-containing organic matter and amorphous carbon remaining

Therefore, the stage leading to the growth of metal grains is the process of solid-phase grinding. We found that during the process of solid-phase grinding of metal precursors and formic acid, the reaction is very violent, releasing a lot of heat, accompanied by a large release of nitrogen oxides. Directly lead to the agglomeration of the precursor, which significantly affects the grain size of the metal catalyst after calcination

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