The role of gallia in methanol synthesis and of ceria based materials in the production of pure hydrogen

S. COLLINS; M. BALTANÁS; J.J. DELGADO; S. BERNAL; M. CALATAYUD; A. BONIVARDI

Zaragoza

Workshop; Understanding Structure and Functions of Reducible Oxide Systems: A Challenge for Theory and Experiment; 2011

Prediction of catalytic performance on “real” catalysts requires an intensive experimentalwork on powder catalysts that includes the scrutiny and uncoupling of different variablesinvolved in the process . Our approach will be outlined in the case of methanol synthesis fromcarbon oxides on Pd-Ga2O3 based catalysts. Results of catalytic activity tests on a Berty-typereactor are modeled using a mechanism derived mainly from intensive infrared spectroscopydata [1-3]. Low and high-pressure transmission infrared studies of the mechanism of the CO2hydrogenation are presented. It is proposed that (bi)carbonate species on gallia surface aresequentiatly hydrogenated to formate, methylenbisoxide and methoxy groups by hydrogenwhich spillovers from palladium surface sites [4]. Additionally, the detrimental effect ofcarbon monoxide is considered into the model to explain the lower productivity to methanol.The role of formate species is supported by means of periodic DTF calculations [5]. Next,new results on ceria based materials used as supports in the study of the water gas shift andcarbon monoxide preferential oxidation reactions for the purification of hydrogen also will beconsidered