ChemInform Abstract: Temperature-programmed Desorption Study of the Interactions of H2, CO and CO2 with LaMnO3.

ChemInform Abstract

The results of TPD and IR spectroscopy show that H₂ adsorbs molecularly on reduced Mn²⁺ sites. The oxide surface undergoes reduction at temp. much lower than those needed for reduction of the bulk. CO adsorption yields CO and CO₂ desorption peaks which are assigned to monodentate and bidentate carbonate groups interacting with Mn3+. Desorption peaks attributed to linear and bridged CO species adsorbed on Mn²⁺ are also observed. CO₂ adsorption results in monodentate and bidentate carbonate groups interacting with Mn³⁺ and Mn²⁺ (or La³⁺), respectively. Coadsorption of CO and H₂ produces an oxygenated species by interaction of CO and H₂ on the same adsorption center.