关键词: 共沉淀法, 溶胶凝胶法, Cu-Mn-Si催化剂, 仲丁醇, 甲乙酮, 脱氢

Abstract: Cu-Mn-Si catalysts were prepared by coprecipitation method and sol-gel method respectively, and their performance in the reaction of 2-butanol dehydrogenation to methyl ethyl ketone was investigated. The catalysts prepared by the two methods were characterized by X-ray diffraction, programmed temperature reduction, nitrogen adsorption desorption and temperature programmed oxidation. The results showed that the crystal structures of Cu-Mn complex in the catalysts prepared by different methods were different. The crystal phase of CuMn₂O₄ in the catalyst prepared by coprecipitation and sol-gel methods belonged to JCPDS 71-1142 and JCPDS 34-1400, respectively. The catalyst prepared by sol-gel method had small crystal size, good dispersion and large specific surface area, so it had high activity. The addition of Mn did not improve the performance of the catalyst prepared by sol-gel method, but could decrease the reduction temperature of the catalyst prepared by coprecipitate method and improve the dispersion of copper components in the catalyst, thus improving the performance of the catalyst. Among the catalysts prepared by sol-gel method, Cu-Si catalyst had the highest conversion rate of 2-butanol, selectivity and yield of methyl ethyl ketone, reaching 99.26%, 99.19% and 98.45%, respectively. When n (Cu)∶n (Mn)∶n (Si) = 0.8∶0.2∶1, the catalysts prepared by coprecipitation method had the highest conversion rate of 2-butanol, reaching 94.92%, the selectivity of methyl ethyl ketone was 98.53%, and the yield of methyl ethyl ketone was 93.52%.

Key words: coprecipitation method, sol-gel method, Cu-Mn-Si catalyst, 2-butanol, methyl ethylketone, dehydrogenation