Methane oxidation to ethanol by a molecular junction photocatalyst

• 成果类型: Article
• 署名作者: Xie, Jijia; Fu, Cong; Quesne, Matthew G.; Guo, Jian; Wang, Chao; Xiong, Lunqiao; Windle, Christopher D.; Gadipelli, Srinivas; Guo, Zheng Xiao; Huang, Weixin; Catlow, C. Richard A.; Tang, Junwang
• 署名单位: University of London; University College London; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Cardiff University; University of Leeds; University of London; University College London; Tsinghua University; University of Hong Kong
• 刊物名称: Nature
• ISSN/ISSBN: 0028-1829
• DOI: 10.1038/s41586-025-08630-x
• 发表日期: 2025-03-13
• 关键词: total-energy calculations; conversion; hydroxyl; nanoparticles; oxide; o-2; ch4

摘要

Methane, the main component of natural and shale gas, is a significant carbon source for chemical synthesis. The direct partial oxidation of methane to liquid oxygenates under mild conditions1, 2-3 is an attractive pathway, but the inertness of the molecule makes it challenging to achieve simultaneously high conversion and high selectivity towards a single target product. This difficulty is amplified when aiming for more valuable products that require C-C coupling4,5. Whereas selective partial methane oxidation processes1, 2-3,6, 7, 8-9 have thus typically generated C1 oxygenates6,7, recent reports have documented photocatalytic methane conversion to the C2 oxygenate ethanol with low conversions but good-to-high selectivities4,5,8, 9, 10, 11-12. Here we show that the intramolecular junction photocatalyst covalent triazine-based framework-1 with alternating benzene and triazine motifs13,14 drives methane coupling and oxidation to ethanol with a high selectivity and significantly improved conversion. The heterojunction architecture not only enables efficient and long-lived separation of charges after their generation, but also preferential adsorption of H2O and O2 to the triazine and benzene units, respectively. This dual-site feature separates C-C coupling to form ethane intermediates from the sites where center dot OH radicals are formed, thereby avoiding over-oxidation. When loaded with Pt to further boost performance, the molecular heterojunction photocatalyst generates ethanol in a packed-bed flow reactor with greatly improved conversion that results in an apparent quantum efficiency of 9.4%. We anticipate that further developing the 'intramolecular junction' approach will deliver efficient and selective catalysts for C-C coupling, pertaining, but not limited, to methane conversion to C2+ chemicals.