不同方法制备的Cu-Mn-La-Zr催化剂上二氧化碳加氢制甲醇反应机理研究  

Mechanistic study on the hydrogenation of CO2 to methanol over Cu-Mn-La-Zr catalysts prepared by different methods

作　　者：王世强 杨金海[1] 赵宁[1] 肖福魁[1] WANG Shi-qiang;YANG Jin-hai;ZHAO Ning;XIAO Fu-kui(State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049

出　　处：《燃料化学学报（中英文）》2023年第7期970-976,共7页Journal of Fuel Chemistry and Technology

摘　　要：通过原位红外和H_(2)-TPD表征,比较研究了由共沉淀法(CMLZ-CP)、溶胶凝胶法(CMLZ-S)、水热法(CMLZ-H)制备的Cu-Mn-La-Zr催化剂上二氧化碳加氢制甲醇的反应历程。结果表明,催化剂表面羟基对二氧化碳加氢制甲醇反应有一定的促进作用,并且催化剂上的二氧化碳加氢反应均遵循甲酸盐(HCOO^(*))和羧酸盐(COOH^(*))路径。CMLZ-CP和CMLZ-H催化剂更倾向于羧酸盐路径,而CMLZ-S催化剂更倾向于甲酸盐路径。CMLZ-CP催化剂有最强的H_(2)活化能力,从而表现出最高的CO_(2)转化率和甲醇产率,而CMLZ-H催化剂有更高的中强碱性位点和氧缺陷占比,使得中间物种更倾向于加氢合成甲醇,从而表现出最高的甲醇选择性。The reaction routes for the CO_(2) hydrogenation to methanol over a series of Cu-Mn-La-Zr catalysts prepared by different methods,viz.,CMLZ-CP by co-precipitation,CMLZ-S by sol-gel method and CMLZ-H by hydrothermal method,were comparatively investigated by in-situ DRIFT and H_(2)-TPD characterization.The results indicate that the surface hydroxyl groups on these catalysts contribute to the CO_(2) hydrogenation to methanol and the reaction may follow the formate(HCOO^(*))and carboxylate(COOH^(*))routes.The carboxylate pathway is preferred for the reaction over the CMLZ-CP and CMLZ-H catalysts,whereas the formate pathway dominates in the reaction over the CMLZ-S catalyst.The CMLZ-CP catalyst shows the strongest ability to activate H_(2) and thus exhibits the highest CO_(2) conversion and methanol yield.In contrast,the CMLZ-H catalyst has high percentage of medium to strong basic sites and oxygen defects,which favor the hydrogenation of intermediate species to methanol,and thus exhibits the highest selectivity to methanol.

关 键 词：CO_(2)加氢 甲醇 反应机理 

分 类 号：O643.36[理学—物理化学] O623.411[理学—化学]