It is critical to develop a catalyst made of earth-abundant elements highly active for a complete oxidation of methane at a relatively low temperature. NiCo2O4 consisting of earth-abundant elements which can completely oxidize methane in the temperature range of 350-550oC. Being a cost-effective catalyst, NiCo2O4 exhibits activity higher than precious metal-based catalysts. Its higher catalytic activity at the relatively low temperature results from the integration of nickel cations, cobalt cations, and surface lattice oxygen atoms/oxygen vacancies at the atomic scale. Operando studies of complete oxidation of methane on NiCo2O4 and DFT calculations show that methane dissociates to methyl on nickel cations and then couple with surface lattice oxygen atoms to form –CH3O with a following dehydrogenation to CH2O; a following oxidative dehydrogenation forms CHO; CHO is transformed to product molecules through two different sub-pathways including dehydrogenation of OCHO and CO oxidation. The integration of operando studies and DFT calculations provided a picture of the reaction mechanism of complete oxidation of CH4 on NiCo2O4 at a molecular level.

Integration of operando studies of catalyst surface during catalysis and DFT calculations for mechanistic understanding at a molecular level

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.