清华大学唐军旺研究团队报道了，用分子结光催化剂将甲烷氧化为乙醇。相关研究成果于2025年1月20日发表在《自然》。

甲烷是天然气和页岩气的主要成分，是化学合成的重要碳源。在温和条件下，甲烷直接部分氧化为液态含氧化合物是一种有吸引力的方法，但分子的惰性使得同时实现对单一目标产物的高转化率和高选择性变得具有挑战性。

当期望制备C-C耦合的更有价值的产品时，这种困难会加剧。虽然选择性部分甲烷氧化过程通常会产生C₁含氧物，但最近的报告记录了光催化甲烷转化为C₂含氧物乙醇，转化率低，但选择性好。

该文中，研究表明，分子内结光催化剂CTF-1具有交替的苯和三嗪基团，以高选择性和显著提高的转化率驱动甲烷偶联和氧化为乙醇。异质结结构不仅能够在电荷产生后有效和长期地分离电荷，而且能够分别将H₂O和O₂优先吸附到三嗪和苯单元上。

这种双位点特征将形成乙烷中间体的C-C偶联与形成OH自由基的位点分开，从而避免了过度氧化。当负载Pt以进一步提高性能时，分子异质结光催化剂在填充床流动反应器中产生乙醇，转化率提高，表观量子效率为9.4%。

研究预计，进一步发展“分子内连接”方法将为C-C偶联提供高效和选择性的催化剂，包括但不限于甲烷转化为C₂₊化学品。

附：英文原文

Title: Methane oxidation to ethanol by a molecular junction photocatalyst

Author: 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

Issue&Volume: 2025-01-20

Abstract: Methane, the major 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 conditions1–3 is an attractive pathway, but the molecule’s inertness 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. While selective partial methane oxidation processes1-3,6-9 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 selectivities4,5,8-12. Here, we show that the intramolecular junction photocatalyst CTF-1 with alternating benzene and triazine motifs7,13 drives methane coupling and oxidation to ethanol with a high selectivity and much 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 OH radicals are formed and thereby avoids overoxidation. When loaded with Pt to boost performance further, the molecular heterojunction photocatalyst generates ethanol in a packed-bed flow reactor with 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.

DOI: 10.1038/s41586-025-08630-x

Source: https://www.nature.com/articles/s41586-025-08630-x