Method for preparing hydrophobic Cr-Ce-based catalyst through ultrasound-hydrogen reduction

Abstract

The invention discloses a method for preparing a hydrophobic Cr-Ce-based catalyst through ultrasound-hydrogen reduction. The method comprises the following steps: 1, codissolving chromium nitrate and cerium nitrate in deionized water to prepare a mixed solution of chromium nitrate and cerium nitrate; 2, adding Al2O3 particles to the mixed solution, oscillating and carrying out ultrasonic dipping at a constant temperature, drying, and calcinating to obtain solid particles; and 3, carrying out reduction processing on the solid particles in hydrogen, and calcinating the solid particles in air toprepare the hydrophobic Cr-Ce-based catalyst. The catalyst prepared through the method of the invention is mainly used for catalyzing the combustion of volatile organic compounds containing chlorine,the method which allows noble metals to be replaced with transition metals allows the cost to be reduced and the high activity of the catalyst to be simultaneously maintained, and the catalyst can catalyze the combustion of the volatile organic compounds containing chlorine at a low temperature; and the catalyst which still has a high activity at a high extraneous humidity has a good practical application prospect.

Description

technical field [0001] The invention belongs to the field of catalytic chemistry and relates to a preparation method of a catalyst, in particular to a method for preparing a hydrophobic Cr-Ce-based catalyst by ultrasonic-hydrogen reduction. Background technique [0002] Volatile organic compounds (abbreviation: VOCs) are a class of highly toxic and polluting chemical substances. Chlorine-containing volatile organic compounds (abbreviation: CVOCs) belong to one of them. They are extremely volatile and stable in the atmosphere for a long time. If it does not degrade, it will cause great harm to human health and the ecological environment. Among the CVOCs removal technologies, the catalytic combustion method is considered to be a more economical and feasible method to deal with CVOCs pollution because it can carry out catalytic oxidation reaction at a lower temperature, has lower energy consumption, high removal efficiency, and wide application range. However, at present, the ...

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Problems solved by technology

Studies have shown that supported Cr-based catalysts have the highest catalytic combustion activity for CVOCs, but the complete combustion temperature of most of the transition metal catalysts for several common CVOCs such as p-chlorobenzene, dichloroethane, and trichloroethylene is above 350 °C. Activity still needs to be improved

[0004] In addition, when the relative humidity of the external environment is high, a large number of water molecules form competitive adsorption on the surface of the catalyst to occupy the active sites, resulting in a sharp decline in the activity of the catalyst for catalytic oxidation of CVOCs.

The addition of water vapor causes chlorobenzene and water molecules to compete for adsorption on the surface of the catalyst, reducing the effective active sites on the surface of the catalyst and reducing the content of surface active species, thereby reducing the activity of the catalyst, resulting in a reduction in the efficiency of catalytic combustion to control CVOCs pollution. cost increase

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