Catalyst for catalytic methane oxidation and preparation method thereof

Abstract

The invention discloses a catalyst for catalytic methane oxidation and a preparation method thereof. The catalyst has a tin-based solid solution hydrolysate coated core-shell structure, the supporter is micro powder of the tin-based solid solution hydrolysate coated core-shell structure, and the core-shell structure is a modified aluminum oxide core-shell structure; the tin-based solid solution is the one doped with rare earth or transition metal, the reaction general formula of the tin-based solid solution is SnxM1-xO2, and in the formula, M is one of the rare earth and the transition metal; x is a coefficient; and the catalyst comprises 10-70 mass percent of tin-based solid solution and the balance of rare earth modified aluminum oxide or alkaline-earth metal modified aluminum oxide. By adopting the tin-based solid solution hydrolysate coated core-shell structure, the consumption of tin rich solid solution is reduced to 10-30%, and the catalyst has excellent thermal stability and low-temperature activity; the raw materials are readily available non-noble metals, so the cost is low; and the catalyst is simple in preparation, has light pollution, facilitates large-scale industrialized production, and is suitable for catalytic oxidation treatment of natural gas automobile exhaust of which the methane concentration is less than 4%.

Description

technical field [0001] The invention relates to a methane oxidation catalyst, in particular to a catalyst for catalytic oxidation of methane and a preparation method thereof. Background technique [0002] Existing noble metal-based methane catalytic oxidation catalysts have a strong ability to activate chemical bonds O-O and C-H, making originally very stable molecules form highly reactive free radicals, thereby triggering chain reactions. Compared with catalytic oxidation catalysts, it has higher catalytic activity. However, in actual use, due to the problems of poor stability and easy sintering of noble metals, some catalysts are improved by improving the carrier of noble metals or palladium Pd and other platinum group metals platinum Pt , osmium Os, iridium Ir, ruthenium Ru, rhodium Rh at least one common method for making double noble or multi-noble metal catalysts has not yet achieved significant results in improving its thermal stability, and the price is expensive, so...

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Problems solved by technology

[0009] The composite oxides used in the above two catalysts are prepared by roasting at a temperature of 500°C to 700°C for 4 hours. It is difficult to use stably at a temperature higher than 700°C, and the methane combustion reaction is a strong exothermic reaction. The temperature of complete combustion is generally higher than 700°C, therefore, the above two catalysts are not suitable for catalytic oxidation of methane