Low‐T CO Oxidation over Cu−CHA Catalysts in Presence of NH3: Probing the Mobility of CuII Ions and the Role of Multinuclear CuII Species

Abstract

The Cover Feature portrays two CuII ions as trapeze artists swinging inside a CHA zeolite cage until they join hands to form a single complex. In their Communication, reporting CO titration experiments over preoxidized Cu-CHA catalysts, R. Villamaina et al. provide evidence that NH3 ligands, like trapezes, mobilize initially isolated CuII ions to form the dimeric complexes with removable oxygen needed for CO oxidation. This is confirmed by transient kinetic analysis, which shows that the rate of CuII reduction is 2nd order in the ZCuIIOH species. These findings may be relevant for elucidation of the reduction half cycle in the redox mechanism of the Standard NH3-SCR reaction over Cu-CHA systems. More information can be found in the Communication by R. Villamaina et al.