Multifunctional metal-based catalysts for selective oxidation of small molecules

Selective oxidation is a key green technology for the conversion of small molecules into value-added oxygenates, with important applications in high-end chemicals, electronic-grade materials and clean fuels. This feature article explores a sequence of selective oxidation reactions, progressing from the initial activation of methane to the subsequent upgrading of methanol and dimethyl ether into high-value oxygenates like methylal, methyl formate, and polyoxymethylene dimethyl ethers. These processes involve C-H and O-H bond activation and C-O chain growth. Metal-based catalysts play an essential role in catalytic oxidation due to their excellent oxygen activation ability and tunable electronic properties. Especially, multifunctional synergistic catalytic systems provide an effective strategy to manage complex reactions by integrating synergistic active sites. This review discusses design strategies for such catalysts, from three perspectives: atomic-level control of active sites, interface engineering, and multicomponent composites. A primary objective is to elucidate how active site design dictates the behavior of oxygen species and the transformation pathways of key intermediates. Moreover, the influence of the catalyst structure on reaction mechanisms and dynamic pathways is emphasized. Finally, we outline current challenges and future directions for the rational design of efficient and selective oxidation catalysts.