Thermal-structural characterization and H2 generation capability of novel CeO2/graphene catalyst

Abstract

This work focuses on the obtaining and studying a graphene-supported ceria catalyst by a simple, economic and reproducible method. The catalyst is intended for H2 generation from water dissociation via water gas shift reaction (WGSR). Different characterization techniques were used to obtain the thermal-structural and elemental information of the catalysts synthesized by a microwave-initiated polyol method. The as-prepared catalyst (graphene-supported) exhibits excellent thermal resistance and lower temperature activation than a conventional catalyst supported on alumina. The catalytic performance of the material was evaluated by running the WGSR, in which the conversion of CO was twice in comparison with that obtained using the ceria supported in an alumina support and the methane selectivity was reduced, from 31% to 16.1% for alumina-supported and graphene-supported, respectively. Besides, the graphene-supported CeO2/graphene catalyst exhibits higher selectivity towards H2 generation than alumina-supported (43.1% vs 40.6%), as a consequence of synergism between ceria and graphene, which was evaluated using EELS technique, improving the catalytic activity of the material by the spillover effect. Finally, we suggest the use of this novel composite as support for metallic nanoparticles.