The active sites of Cu-ZnO catalysts for water gas shift and CO hydrogenation reactions

Cu-ZnO-Al2O3 catalysts are used as the industrial catalysts for water gas shift (WGS) and CO hydrogenation to methanol reactions. Herein, via a comprehensive experimental and theoretical calculation study of a series of ZnO/Cu nanocrystals inverse catalysts with well-defined Cu structures, we report that the ZnO-Cu catalysts undergo Cu structure-dependent and reaction-sensitive in situ restructuring during WGS and CO hydrogenation reactions under typical reaction conditions, forming the active sites of Cu-Cu(100)-hydroxylated ZnO ensemble and CuCu(611)Zn alloy, respectively. These results provide insights into the active sites of Cu-ZnO catalysts for the WGS and CO hydrogenation reactions and reveal the Cu structural effects, and offer the feasible guideline for optimizing the structures of Cu-ZnO-Al2O3 catalysts. Identification of active sites of a catalyst is the Holy Grail in heterogeneous catalysis. Here, the authors successfully identify the Cu-Cu(100)- hydroxylated ZnO ensemble and CuCu(611)Zn alloy as the active sites of Cu-ZnO catalysts for water gas shift and CO hydrogenation reactions, respectively.

Automated summary

In this study, the authors investigated the restructuring of ZnO-Cu catalysts during WGS and CO hydrogenation reactions, leading to the formation of different active sites. The identification of Cu-Cu(100)-hydroxylated ZnO ensemble and CuCu(611)Zn alloy as active sites provides valuable insights for optimizing the structures of Cu-ZnO-Al2O3 catalysts.