Effects of precipitation manner on catalytic performance of CuO/ZnO/Al₂O₃ catalyst aging under microwave irradiation

CuO/ZnO/Al₂O₃ precursors were prepared by different precipitation manner; microwave irradiation was introduced in aging process. The effects of precipitation manner on composition of precursor, micro structure and performance of catalyst were characterized by means of XRD, DTG, H₂-TPR. The reaction results indicated that the order of catalytic activity was Stepwise II ＞ Parallel-flow ＞ Stepwise I ＞ Reversed ＞ Forward. When Al(NO₃)₃ solution and Na₂CO₃ solution were precipitated first and then Cu(NO₃)₂-Zn(NO₃)₂ solution were precipitated with remaining Na₂CO₃, the prepared precursor contained more (Cu, Zn)₅(CO₃)₂(OH)₆, which possessed well-dispersed CuO, strong synergy in CuO-ZnO and low H₂-reduction temperature after calcination.