Cu/ZrO2 catalyst as well as preparation method and use of Cu/ZrO2 thereof

Abstract

The invention provides a Cu / ZrO2 catalyst as well as a preparation method and use of the Cu / ZrO2 thereof. According to the preparation method, a Cu / ZrO2 precursor is reduced in alkaline and medium temperature environments by virtue of hydrazine hydrate, the alkaline environment is beneficial to the reducibility of hydrazine hydrate, and the medium temperature environment is beneficial to the acceleration of reduction reaction. By controlling the use amount and reduction time of hydrazine hydrate, the reduction degree of the catalyst is controlled; and by adding ice water, the reduction reaction can be rapidly terminated. According to the preparation method, the Cu / ZrO2 catalyst is prepared in the alkaline and medium temperature environments by virtue of hydrazine hydrate, Cu in the catalyst has three valence states including Cu<0>, Cu<+> and Cu<2+> in a molar ratio of 1 to (0.20-0.35) to (0.01-0.06), and the performance of the catalyst is excellent. The preparation method has the beneficial effects that the time is short, the energy consumption is low, and the reduction degree of the catalyst can be effectively controlled; and the yield of iminodiacetic acid salt prepared from diethanol amine through the catalysis Cu / ZrO2 exceeds 98%, the shortest reaction time is 2.3h, and the Cu / ZrO2 catalyst has good industrial application prospects.

Description

technical field [0001] The invention relates to a copper-based catalyst. Background technique [0002] Iminodiacetic acid prepared by acidification of iminodiacetic acid salt is an important fine chemical raw material, mainly used in the preparation of broad-spectrum insecticide glyphosate. There are two main industrial production routes of glyphosate: glycine route and iminodiacetic acid route. The iminodiacetic acid route is to synthesize iminodiacetic acid first, then react iminodiacetic acid with formaldehyde, phosphorous acid, etc. to form diglyphosate, and then peroxidate diglyphosate to obtain glyphosate. At present, the iminodiacetic acid route is the most advanced method for producing glyphosate in the world, and one of the key points of this route is the preparation of the intermediate product iminodiacetic acid. [0003] Catalysts for the preparation of iminodiacetates from diethanolamine are generally copper-based catalysts. Chinese patent CN101733100A (2009),...

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Problems solved by technology

Chinese patent CN101733100A (2009), CN1398850A (2003) and U.S. patent US5292936 (1994), the Cu / ZrO 2 A small amount of nickel, molybdenum, cobalt, vanadium, titanium, etc. are added to the catalyst to form a composite catalyst, which effectively improves the service life of the catalyst. The yield of iminodiacetic acid is about 95%, but adding precious metals increases the cost of the catalyst

[0005] Existing methods for preparing Cu-based catalysts usually start from H 2 Reducing its CuO precursor, this process consumes high energy, takes a long time to reduce, and the degree of reduction is not easy to control, which leads to unsatisfactory catalytic effect of the catalyst

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