892 resultados para GRAPHENE-CEO2
Resumo:
Ceria catalysts were found active and selective to the oxidehydrogenation of ethane (ODE) with CO2 and the actual contribution for C2H4 formation from heterogeneous catalysis was 75-55% in the range 953-993 K. The presence of calcium ions in solid solution in the ceria crystalline network increased significatively the selectivity to ethene and the efficiency of CO2 as oxidant in the heterogeneous reaction. (C) 2000 Elsevier Science B.V. All rights reserved.
Resumo:
The structural features and catalytic properties of Pt-Sn/CeO2 catalysts prepared by modified polyol method were extensively investigated for the complete oxidation of ethanol. CO chemisorption, TPR, DTA and XPS measurements identically indicated that the electronic configuration of Pt by Sn as well as the formation of PtSn alloy were the key factors in determining the nature of the active sites, A strong Pt/Sn atomic ratio dependence of catalytic perfortmances was observed. which was explained in terms of the change., in the Surface structure of metal phases and the electronic Pt-Sn interaction. (c) 2005 Elsevier B.V. All rights reserved.