AHTD法铜基催化剂中氧化铝的作用

由合成气催化合成甲醇是重要的工业过程,其中使用的Cu/Zn/Al催化剂一直是人们广泛研究的对象,这种催化剂常由金属硝酸盐用NaHCO_3(或Na_2CO_3)在一定的pH值下沉淀生成金属复合碳酸盐,再加热分解成氧化物制得。该法步骤繁琐,耗时多。本文采用雾化高温分解法(Aerosol High Temperature Decomposition,简称AHTD法)扶金属硝酸盐一步制得催化剂氧化物,并研究了Cu/Zn/Al催化剂中Al_2O_3对催化活性、表面性质的影响。

Effect of Alumina on Cu-based Catalysts Prepared by AHTD

Effect of alumina on Cu-based catalysts prepared by aerosol high temperature decomposition was studied by different physicochemical techniques. The results show that alumina was dispersed at a high level in the catalysts, which made CuO crystal grain dispersive and increased the catalyst surface area, the reaction activities from CO+H2 to methanol and stabilities against reoxidation. The surface enrichment of alumina was increased with the decrease of ZnO, but was not related with the concentrations of CuO. The content of Cu on the surface is nearly constant for a series of Cu/Zn/Al catalysts, i.e. Cu/(Cu+Zn + Al) = 16. 4%.