On the Effect of the Synthesis Route of the Support in Co3O4/CeO2 Catalysts for the Complete Oxidation of Methane.

Abstract

Six ceria supports synthesized by various synthesis methodologies were used to deposit cobalt oxide. The catalysts were thoroughly characterized, and their catalytic activity for complete methane oxidation was studied. The supports synthesized by direct calcination and precipitation with ammonia exhibited the best textural and structural properties as well as the highest degree of oxidation. The remaining supports presented poorer textural properties to be employed as catalytic supports. The cobalt deposited over the first two supports presented a good dispersion at the external surface, which induced a significant redox effect that increased the number of Co3+ ions on their surface. Consequently, the presence of highly active lattice oxygen species on the surface of these catalysts was favored. Additionally, the optimal active catalyst (Co-DC) revealed a significant resistance to water vapor inhibition, owing to the high hydrophobicity of the ceria support.