Direct Conversion of Syngas to Higher Alcohols over Multifunctional Catalyst: The Role of Copper-Based Component and Catalytic Mechanism
Caiqi Wang, Tiejun Lin, Xingzhen Qi, Fei Yu, Yongwu Lu, Liangshu Zhong, Yuhan Sun
Abstract
A multifunctional catalyst composed of CoMn and CuZnAlZr oxides can dramatically increase higher-alcohol selectivity. However, the role of Cu-based components and catalytic mechanism are still unclear. Herein, a series of multifunctional catalysts containing CoMn oxides and different Cu-based components were constructed to investigate the influence of a Cu component, and a link between methanol synthesis and higher-alcohol synthesis was established. It was found that the Cu-based components with different methanol synthesis activity showed a different promotional effect for higher-alcohol synthesis. The sole Cu-based component exhibited higher activity for methanol synthesis, and higher selectivity for C2+ oxygenates was achieved for the corresponding mixed catalyst system. In situ DRIFTs indicated that the CHxO* species were mainly produced over the Cu-based components. The formed CHxO* species bridged the CoMn and Cu-based component and promoted the formation of higher alcohols.