Structural properties and catalytic performance of the La-Cu-Zn mixed oxides for CO₂ hydrogenation to methanol

Haijuan Zhan^1,2，Zhiqiang Wu¹，Ning Zhao³，Wanyi Liu¹，Wei Wei⁴

1. School of Chemistry and Chemical Engineering,Ningxia University2. State Key Laboratory of High-efficiency Coal Utilization and Green Chemistry Engineering,Ningxia University3. State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences4. Center for Greenhouse Gas and Environmental Engineering,Shanghai Advanced Research Institute,Chinese Academy of Sciences

摘 要：A series of La-Cu-Zn-O mixed oxide catalysts were synthesized by a co-precipitation method and calcined under different temperatures. The XRD, BET, TPR, N₂ O-adsorption, XPS, SEM and TPD techniques were carried out to measure the aimed catalysts. The results indicated that the chemical environment of lanthanum element changes with the increase of calcination temperature. The La₂ CuO₄ perovskite structure is obtained at the temperature higher than 823 K and the special copper species appear in the perovskites due to the special structure property. The catalysts with La₂ CuO₄ perovskite structure show higher methanol selectivity compared with the mixed copper catalyst. For the perovskite catalysts, the conversion of CO₂ changes with the same tendency of the copper species ratio((Cu^α++Cu⁰)/(Cu_Total)%), which implied both Cu^α+ and Cu⁰ are important active sites in the perovskite catalyst for the reaction.

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