助剂对甲醇乙醇合成异丁醛催化剂结构和催化性能的影响

采用溶胶-凝胶法制备了复合氧化物(SiO2-TiO2)负载的铜基催化剂。测试了含4种不同助剂ZnO、MnO、CaO、MgO的催化剂对甲醇与乙醇一步合成异丁醛的催化性能,并应用TPR,BET,XRD等手段对催化剂结构进行了表征。结果表明,溶胶-凝胶法制备的催化剂可以显著地改善CuO的分散性,降低了CuO的还原温度。同时发现,碱性金属氧化物作助剂可以增强助剂与活性组分之间的协同作用,提高异丁醛的选择性和收率,较适宜的助剂是CaO。在常压、反应温度593K、n(甲醇)/n(乙醇)=2∶1的条件下,乙醇的转化率为71.58%,异丁醛的选择性为50.99%。

Influence of Promoters on the Structure and Performance of the Catalysts for the Synthesis of Isobutyraldehyde from Methanol and Ethanol

Copper-based catalysts supported on composite oxides(SiO_2-TiO_2) were prepared by the sol-gel method.The catalytic performances of the catalysts with different promoters were tested in one-step synthesis of isobutyraldehyde from methanol and ethanol.The structure of the catalysts was characterized with TPR,BET and XRD techniques.The results show that the catalysts prepared by sol-gel method obviously improved the dispersion of CuO and loweved reduction temperature.Alkali metal oxides improve the synergistic effect between active component and promoters,and increase selectivity and yield of isobutyraldehyde.The optimum promoter is CaO.Under atmospheric pressure,593K reaction temperature and 2∶1 molar ratio of methanol to ethanol,the conversion of ethanol was 71.58% and the selectivity to isobutyraldehyde was 50.99%.