Wang Xueyuan, Xin Xueshang, Xiong Lunqiao, Yang Jianlong, Wang Tieou, Yang Yang, Huang Zhipeng, Luo Nengchao, Tang Junwang, Wang Feng
State Key Laboratory of Catalysis and Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
School of Chemistry, Dalian University of Technology, Dalian, 116024, China.
Angew Chem Int Ed Engl. 2025 Feb 24;64(9):e202420606. doi: 10.1002/anie.202420606. Epub 2025 Jan 20.
Hydroxy radical (⋅OH) is a prestigious oxidant that allows the cleavage of strong chemical bonds of methane but is untamed, leading to over-oxidation of methane and waste of oxidants, especially at high methane conversion. Here, we managed to buffer ⋅OH in an aqueous solution of photo-irradiated Fe, where ⋅OH almost participates in methane oxidation. Due to the interaction between Fe and SO , the electron transfer from OH to excited-state Fe for ⋅OH generation is retarded, while excessive ⋅OH is consumed by generated Fe to restore Fe. When combined with a Ru/SrTiO:Rh photocatalyst, the buffered ⋅OH converts methane to C hydrocarbons and H with formation rates of 246 and 418 μmol h, respectively. The apparent quantum efficiency reaches 13.0±0.2 %, along with 10.2 % methane conversion and 81 % C selectivity after 80 hours of reaction. Overall, this work presents a strategy for controlling active radicals for selective and efficient photocatalysis.
羟基自由基（·OH）是一种强大的氧化剂，能够断裂甲烷的强化学键，但它不受控制，会导致甲烷过度氧化和氧化剂浪费，尤其是在甲烷转化率较高时。在此，我们设法在光辐照铁的水溶液中缓冲·OH，在该溶液中·OH几乎参与甲烷氧化反应。由于铁与硫酸根之间的相互作用，从氢氧根向激发态铁转移电子以生成·OH的过程受到阻碍，而过量的·OH会被生成的亚铁离子消耗以恢复铁离子。当与钌/钛酸锶：铑光催化剂结合时，被缓冲的·OH将甲烷转化为碳氢化合物和氢气，生成速率分别为246和418 μmol/h。表观量子效率达到13.0±0.2%，反应80小时后甲烷转化率为10.2%，碳氢化合物选择性为81%。总体而言，这项工作提出了一种控制活性自由基以实现选择性高效光催化的策略。
