Characterization of the surfaces of MgO–ZnO solid solutions by CO and H2 adsorption at room temperature

Abstract

Solid solutions of ZnO in MgO with larger surface areas than those previously reported in the literature have been prepared and their formation tested by ultraviolet–visible reflectance spectroscopy. The surface chemistry of CO and H₂(or D₂) interactions has been studied by infrared spectroscopy. Large differences with respect to the surface chemistry of the pure oxides have been found. CO is mainly adsorbed on MgO couples as oxidized carboxylate-type species, which are stable up to 373 K and then transformed into carbonate-type species. H₂ is mainly chemisorbed by heterolytic dissociation on three different Zn—O couples.