MOF-derived carbon-supported cobalt oxide catalysts with strong electronic oxide-carbon interactions for selective catalytic oxidation of C-H bonds

Abstract

Carbon-supported metal oxide catalysts are highly important for heterogeneous catalysis. In addition to exciting charge transfer and regulating the electronic structure of the active metal component, the interfacial interaction between carbon and oxide can also affect the adsorption/desorption of reactants. Thus, the construction of electronic metal-support interactions for fine-tuning the performance and selectivity of the resulting heterogeneous catalysts has received widespread attention in recent years. Herein, a one-pot strategy is used to fabricate a novel porous carbon-metal oxide catalyst by pyrolyzing a Co-SiO₂@Co-MOF-74 composite precursor and etching the SiO₂ template. Notably, tunable carbon channels with encapsulated cobalt clusters are formed in situ, and a defined strong electronic interaction between them is demonstrated. Owing to the strong interfacial interaction in this unique microreactor, cobalt oxide clusters can be anchored in a highly dispersed state to provide hierarchical carbon pores and promote charge transfer from the carbon channel to the metal sites. This process leads to enhanced reactant adsorption and activation, thereby promoting the catalytic activity of C-H bond oxidation in toluene. Under optimized conditions, Co-MSC-2 afforded 28 % conversion of toluene and 96 % selectivity for benzaldehyde, and the catalyst maintained remarkable stability. Our research proposes a new type of strong electronic oxide-carbon interaction for developing effective catalysts for C-H bond oxidation.