XPS study on the low-temperature CO shift reaction catalyst: I. The unreduced copper-zinc system

Abstract

X-Ray photoelectron spectroscopy has been used to study CuZn catalysts for the low-temperature CO shift reaction before activation by reduction. Samples with Cu concentrations in the range 3–54% of the total cations and calcination temperatures up to 923 K have been investigated. Single-phase and multiphase precipitates have been compared, showing that several chemico-physical properties are different in the two cases. Evidence has been reached for the existence, in a narrow range of temperatures, of a nonequilibrium solid solution of Cu(II) in ZnO. Also the formation of a solid solution of Zn(II) in CuO has been suggested.