Visible-light-driven conversion of methane to methanol mediated by hydroxyl radical.

Selective oxidation of methane (CH4) to value-added liquid methanol (CH3OH) drives the synthesis of chemicals and energy sustainability. It is extremely challenging to mimic in artificial reaction systems due to the inertness of CH4 molecule and overoxidation to byproducts. In this work, we developed an effective and noble-metal-free iron-based catalyst (UNFe) that delivers exceptional performance of methane oxidation to methanol with visible light at room temperature. Specifically, the hydroxyl radical (OH) generated through FeIII/FeII cycling in UNFe catalyst is essential for promoting activity of methane oxidation. Importantly, the excellent generation yield and selectivity of methanol, up to 289 ± 10 μmol·g-1 and 96%, respectively. This report provides an effective and cost-effective catalyst system for enhanced oxidation of methane to methanol in a facile strategy.