Pd-Promoted Co2NiO4 with lattice Co O Ni and interfacial Pd O activation for highly efficient methane oxidation

Nowadays, developing advanced Pd-based catalysts with highly efficient catalytic activity and long-term stability still presents profound challenges. Here, we prepare a novel Pd-Co2NiO4 catalysts with PdOx species simultaneously embedded into Co2NiO4 lattice and decorated on Co2NiO4 surface in high dispersion. The Pd-Co2NiO4 catalysts shows the attractive activity and excellent stability for methane complete oxidation. Based on the experimental and theoretical analysis, the enhanced methane oxidation activity of Pd-Co2NiO4 catalysts is mainly ascribed to two factors. PdOx species incorporated into Co2NiO4 lattice modulates effectively the electronic structure of catalysts, which promotes the electron transfer between Co 3d-O 2p hybrid orbital and Ni eg orbital in Co2NiO4 and thus benefits the activation of adjacent lattice O in CoONi hybridization, resulting in the rapid migration and activation of lattice oxygen in Co2NiO4 support (Factor I). In addition, the deposition of PdOx species on the Co2NiO4 surface tunes the metal-support interface interactions and promotes the activation of PdO bonds, giving rise to more facile CH4 activation ability (Factor Ⅱ). Collectively, the enhanced catalytic properties of the Pd-Co2NiO4 catalysts originated from the activation of lattice oxygen in the Pd-regulated CoONi hybridization and decorated PdOx sites. This study presented here not only gives further insight into the metal-support electronic interaction, but paves the promising way for the rational fabrication of next-generation environmental catalysts.