Photo-Driven Iron-Induced Non-Oxidative Coupling of Methane to Ethane

Authors: Huizhen Zhang, Wanfu Zhong, Qiaobin Gong, Pengfei Sun, Xuejiao Wu, Xiaozhen Fei, Sha Xu, Qinghong Zhang, Gang Fu, Shunji Xie*, Ye Wang 

Abstract: Photo-driven CH4 conversion to multi-carbon products and H2 is attractive but challenging, and the development of efficient catalytic systems is critical. Herein, we construct a solar energy-driven iron ions redox cycle for combining CH4 conversion and H2 production. A photo-driven iron-induced reaction system is developed, which is efficient at selective coupling of CH4 as well as conversion of benzene and cyclohexane under mild conditions. For CH4 conversion, 94% of C2 selectivity and 8.4 μmol h−1of C2H6 formation rate is achieved. Mechanism studies reveal that CH4 coupling is induced by hydroxyl radical, which is generated by photo-driven intermolecular charge migration of Fe3+ complex. The delicate coordination structure of [Fe(H2O)5OH]2+ complex ensures the selective C−H bond activation and C−C coupling of CH4. The produced Fe2+ can be used to reduce the potential for electrolytic H2 production, and then turns back into Fe3+, forming an energy-saving and sustainable recycle system.

Link: https://onlinelibrary.wiley.com/doi/10.1002/anie.202303405