络合剂对固相法Cu/ZnO/In_(2)O_(3)催化剂的CO_(2)加氢制甲醇反应性能的影响

Effect of complexing agents on the performances of Cu/ZnO/In_(2)O_(3) catalysts for CO_(2) hydrogenation to methanol by solid-state grinding method

为了促进催化剂中Cu物种的分散,在金属硝酸盐中分别加入草酸、甲酸和柠檬酸,采用固态研磨合成Cu/ZnO/In_(2)O_(3)催化剂.结果表明:草酸的加入对Cu的分散效果最好,在280℃,2 MPa,3.6 L·gcat^(-1)·h^(-1),V(H2)∶V(CO_(2))=3∶1时,甲醇收率最高,达到2.1 mmol·gcat^(-1)·h^(-1).但甲酸在高温下会分解为CO_(2)和H_(2),导致制备的CuO/ZnO/In_(2)O_(3)催化剂部分还原,随后此催化剂在H_(2)预处理后被过度还原,形成Cu_(3)In_(7)合金相,导致甲醇产率降低.

In order to promote the dispersion of Cu species in the catalyst,oxalic acid,formic acid,and citric acid were added to the metal nitrates,and Cu/ZnO/In_(2)O_(3) catalysts were synthesized by solid-state grinding.The results showed that the addition of oxalic acid had the best dispersion effect on Cu,and a maximum methanol yield of 2.1 mmol·gcat-1·h^(-1)was obtained at 280℃,2 MPa,3.6 L·gcat^(-1)·h^(-1),V(H_(2))∶V(CO_(2))=3∶1.However,formic acid decomposed into CO_(2) and H2 at high temperatures,leading to partial reduction of the CuO/ZnO/In_(2)O_(3) catalyst,followed by over-reduction after H_(2) pretreatment,forming Cu3In7 alloy phase,thereby reducing the methanol yield.