并流淤浆混合法制备铜基甲醇合成催化剂及助剂Al2O3的作用研究

A series of CuO/ZnO/γ-Al2O3 catalysts with different Al2O3 contents were prepared using parallelslurrymixing method, in which an aqueous solution of Cu2+and Zn2+mixed nitrates and an aqueous solution of Na2CO3 were poured into a precipitation vessel containing γ-Al2O3 slurry in a parallelflow manner. The catalyst structure and its performance for methanol synthesis were investigated. The results indicated that Al2O3 as a structural promoter can inhibit CuO and ZnO crystallites from enlarging during calcination. The catalyst with a Cu∶Zn∶Al ratio of 4∶5∶1 exhibits the highest catalytic activity. With an increase in Al content, the amounts of (Cu0.3Zn0.7)5(CO3)2(OH)6 phase in the catalyst precursor before calcination shows a decrease, whereas those of Cu2CO3(OH)2 phase shows an increase; (Cu0.3Zn0.7)5(CO3)2(OH)6 in the precursor is beneficial to the catalytic activity of the final Cu/ZnO/γ-Al2O3 catalyst.