Near-infrared photon-triggered CH(4)-to-CH(3)OH conversion over plasmonic oxyselenides.

The direct oxidation of methane into methanol exploiting O(2) as oxidant offers an ideal route for methane utilization. Although the reaction is strongly preferred in thermodynamics, conventional catalytic systems always demand intense energy input like high temperatures or high-energy photons (>2.8 eV) to conquer the large kinetic barrier in the conversion process. In this study, we demonstrate that by creation of a suitable plasmonic photocatalyst, namely oxygen-vacancy-rich CuSeO(3-x), the low-energy near-infrared (NIR) photons can serve as the sole energy input to complete CH(4)-to-CH(3)OH conversion with remarkable activity (Apparent quantum yield of 1.5% at 800 nm with Au cocatalyst) and near unity selectivity (ca. 96%) at 25 °C. Such fascinating performance is attributed to a small activation energy measured at 0.28 eV, enabled by the existence of Cu(II)-O(v) species in CuSeO(3-x). Our study suggests that the ensemble of Cu(II)-O(v) constitutes an exceptional active site, which can harness the plasmon-induced hot electrons and meantime brings a kinetically advantageous route for reducing O(2) into •OH radicals greatly favoring methane activation.