CO, CO2 and H2 adsorption on ZnO, CeO2 and ZnO/CeO2 surfaces: DFT simulations

W. G. REIMERS; M.A. BALTANÁS; M.M. BRANDA

JOURNAL OF MOLECULAR MODELING - (Print)

SPRINGER

Lugar: Berlin; Año: 2014 vol. 20 p. 1 - 10

1610-2940

The adsorption of the CO, CO2 and H2 molecules on several ceria and zinc oxidesurfaces was studied by means of periodical DFT calculations and compared withinfrared frequency data. The stable CeO2(111), CeO2(331) and ZnO(0001) perfectfaces were the first substrates considered. Afterwards, the surfaces with oxygenvacancies and a ZnO monolayer grown on Ceria (111) were also studied, to comparethe different surface behaviors and reactivity.The ceria surfaces are substantially more reactive than the ZnO surface in regards the CO2 molecule. The highest adsorption energy value for this molecule was found on the CeO2(111) surface with oxygen vacancy. Regarding the CO and H2 molecules, both have low or very low reactivity on all the studied surfaces, although some reactivity was found for the case of CO adsorbed onto the surfaces with oxygen vacancies, whereas H2 exhibited reactivity in the  CeO2(111) surface with oxygen vacancy. This effort aims to contributing to build firm foundations for novel process developments in the methanol synthesis from carbon oxides, the steam reforming of methanol for hydrogen production and/or the water-gas shift reaction.