Increasing the local electron density of carbons for enhanced O2 activation at room temperature†

Abstract

Room-temperature activation of O₂ into a super dioxide radical (O₂˙⁻) is a crucial step in oxidation processes. Here, the concept of tuning the local electron density of carbons is adopted to develop highly efficient catalysts for molecular oxygen activation. We demonstrate that the π electron of sp² carbons is essential for activating O₂ with the assistance of ultra-micropores, while varying defects or functional groups induce local electron rearrangement of carbons, thereby altering their catalytic capacity. Electron rich non-metallic doping can increase the local electron intensity of modified carbons with improved oxygen activation. In addition, transition-metal-sp²-carbon nano-composites that readily surrender electrons are constructed, achieving O₂˙⁻ formation without spatial confinement. Our findings provide fundamental insights into the intrinsic mechanism of O₂ activation and offer a general protocol for the design and development of advanced carbon catalysts for low-temperature oxidations.