Electrocatalytic Conversion of CH4 to High Value-Added Liquid Fuel over Binary Metal Oxide Tandem Catalysts

Abstract

As the main component (> 85%) of combustible ice and shale gas, methane (CH4), plays a significant role in the greenhouse effect.(1) Although CH4 was widely used to synthesize high value-added Cx oxygenates via indirect industrial reforming with high-energy consumption. The accurate control of oxidation degree in CH4 conversion remains a great challenge.(2) Therefore, it is difficult to achieve high conversion rate and high selectivity at the same time. The convenience and reliability of the control of reaction potential, as one of the advantages of electrocatalysis technology, can effectively address the above problems.(1, 3) Electrochemical technologies of CH4-to-Cx oxygenates are regarded as one of the most attractive pathways to produce bulk industrial liquid fuels.(4) Especially in the premise of clean energy as an energy source, the electrochemical conversion of methane demonstrates very advantageous market potential. In this work, we prepared a ZrO2 modified FeOx binary metal oxides tandem catalyst to accelerate partial oxidation of CH4 under ambient condition. With CO3 2- as an oxidant, ZrO2@FeOx tandem catalyst shows remarkable CH4 conversion performance with large current density gap (13.65 mA cm-2) and long-term electrochemical stability (negligible attenuation (8 %) after 48 hours) in three-electrodes cell. In addition, in a flow reactor, ZrO2@FeOx-based electrode also exhibits a highly stable operating lifespan over 72 hours at a large current density 50 mA cm-2 and achieve a feasible CH4-liqid fuel conversion with high total faradaic efficiency.References F. Liu, Y. Yan, G. Chen and D. Wang, Green Chemistry, 26, 655 (2024).S. Yuan, Y. Li, J. Peng, Y. M. Questell-Santiago, K. Akkiraju, L. Giordano, D. J. Zheng, S. Bagi, Y. Román-Leshkov and Y. Shao-Horn, Advanced Energy Materials, 10, 2002154 (2020).M. R. A. Kishore, S. Lee and J. S. Yoo, Adv Sci (Weinh), 10, e2301912 (2023).L. Fu, R. Zhang, J. Yang, J. Shi, H. Y. Jiang and J. Tang, Advanced Energy Materials, 13 (2023).