Facile Preparation of Cu‐Al Oxide Catalysts and Their Application in the Direct Synthesis of Ethanol from Syngas

A simplified catalytic system K‐Cu/Al 2 O 3 (KCA‐xCu‐ T ) with Cu‐Al oxides was prepared by a facile impregnation method and was successfully applied in the direct synthesis of ethanol from syngas. The results demonstrated that the distribution of CuO, CuAl 2 O 4 , and CuAlO 2 in KCA‐xCu‐ T catalysts can be effectively tuned by varying the calcination temperature ( T /°C) and CuO loading (xCu/wt%). The cooperative effect between Cu 0 and CuAlO 2 (Cu + ) was proved to be responsible for the enhanced ethanol selectivity. Furthermore, the formation of CuAlO 2 could efficiently fix Cu + species in KCA‐10Cu‐900 sample, and thus lead to excellent catalytic stability (300 h at 400 °C). CuAl 2 O 4 itself has no catalytic effect but can be gradually decomposed into Cu + and/or Cu 0 species during reaction, which further influenced the ethanol selectivity (38.4 wt%).