State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai, 200050, People's Republic of China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
Nat Commun. 2019 Jan 31;10(1):506. doi: 10.1038/s41467-019-08454-0.
Direct valorization of methane to its alcohol derivative remains a great challenge. Photocatalysis arises as a promising green strategy which could exploit hydroxyl radical (·OH) to accomplish methane activation. However, both the excessive ·OH from direct HO oxidation and the neglect of methane activation on the material would cause deep mineralization. Here we introduce Cu species into polymeric carbon nitride (PCN), accomplishing photocatalytic anaerobic methane conversion for the first time with an ethanol productivity of 106 μmol g h. Cu modified PCN could manage generation and in situ decomposition of HO to produce ·OH, of which Cu species are also active sites for methane adsorption and activation. These features avoid excess ·OH for overoxidation and facilitate methane conversion. Moreover, a hypothetic mechanism through a methane-methanol-ethanol pathway is proposed, emphasizing the synergy of Cu species and the adjacent C atom in PCN for obtaining C product.
将甲烷直接转化为其醇衍生物仍然是一个巨大的挑战。光催化作为一种很有前途的绿色策略应运而生，它可以利用羟基自由基（·OH）来实现甲烷的活化。然而，直接 HO 氧化产生的过量·OH 和材料对甲烷活化的忽视都会导致深度矿化。在这里，我们将 Cu 物种引入聚合物氮化碳（PCN）中，首次实现了光催化厌氧甲烷转化，乙醇产率达到 106 μmol·g-1·h-1。Cu 改性 PCN 可以管理 HO 的生成和原位分解，以产生·OH，其中 Cu 物种也是甲烷吸附和活化的活性位点。这些特点避免了过量·OH 的过度氧化，并促进了甲烷的转化。此外，还提出了一种通过甲烷-甲醇-乙醇途径的假设机制，强调了 Cu 物种和 PCN 中相邻 C 原子在获得 C 产物方面的协同作用。
