Near-infrared photon-triggered CH<sub>4</sub>-to-CH<sub>3</sub>OH conversion over plasmonic oxyselenides.

Zhang, Xiuming; Jiang, Yuheng; Gu, Hongfei; Zhang, Haoqing; Li, Yuemei; Lu, Zexuan; Zhang, Shuping; Liu, Jia et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

The direct oxidation of methane into methanol exploiting O<sub>2</sub> 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<sub>3-x</sub>, the low-energy near-infrared (NIR) photons can serve as the sole energy input to complete CH<sub>4</sub>-to-CH<sub>3</sub>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<sup>II</sup>-O<sub>v</sub> species in CuSeO<sub>3-x</sub>. Our study suggests that the ensemble of Cu<sup>II</sup>-O<sub>v</sub> constitutes an exceptional active site, which can harness the plasmon-induced hot electrons and meantime brings a kinetically advantageous route for reducing O<sub>2</sub> into •OH radicals greatly favoring methane activation.