Promotion effect of strong CeO2/Co3O4 interfacial interaction for light alkane catalytic removal

Composite oxide catalysts are widely used, while the influence of oxide/oxide interfacial interaction on the catalytic performance for light alkanes combustion still remains to be fully elucidated. Herein, the CeO2/Co3O4 composite oxide catalyst with strong interfacial interaction was constructed using one-pot hydrothermal method. The CeO2/Co3O4 catalyst with the theoretical Ce/Co molar ratio of 5:100 (5 % Ce/Co3O4) showed the optimal propane catalytic combustion activity (T90 %= 258 degrees C, 120,000 mL center dot g-1 center dot h-1), good stability and water resistance. TEM images revealed that the morphology of original rod-shaped Co3O4 was unchanged after Ce modification, with obvious defects formed at the interface. H2-TPR, O2-TPD and EXAFS results demonstrated that the strong CeO2/Co3O4 interfacial interaction promoted the formation of Ce3+-Ov-Co3+ interface structure. The XPS and DFT results suggested that electrons were transferred from Co3O4 to CeO2 through the Co-O-Ce channel, promoting the formation of more Co3+, Ce3+, and interface oxygen vacancies. The kinetic results demonstrated that CeO2/Co3O4 catalyst had higher propane and oxygen adsorption activation ability compared to pure Co3O4, and the propane oxidation reaction over CeO2/Co3O4 catalyst followed the L-H mechanism. In-situ DRIFTS results demonstrated that the reactive oxygen species provided by the Ce3+-Ov-Co3+ interface structure rapidly consumed oxygen-containing intermediates, thereby accelerated the propane oxidation process. This study offers new insights for further investigating the role of strong oxide/oxide interfacial interactions in alkane catalytic combustion.