Gas-Dependent Active Sites on Cu/ZnO Clusters for CH 3 OH Synthesis.

This study describes an instantaneously gas-induced dynamic transition of an industrial Cu/ZnO/Al 2 O 3 catalyst. Cu/ZnO clusters become "alive" and lead to a promotion in reaction rate by almost one magnitude, in response to the variation of the reactant components. The promotional changes are functions of either CO 2 -to-CO or H 2 O-to-H 2 ratio which determines the oxygen chemical potential thus drives Cu/ZnO clusters to undergo reconstruction and allows the maximum formation of Cu-Zn 2+ sites for CH 3 OH synthesis.