Synergistic Effect of Mixed Cations in the Electrochemical Double Layer Enables Highly Efficient Electrochemical CO <sub>2</sub> Methanation
Abstract
Abstract Electrochemical CO 2 methanation is crucial for sustainable carbon recycling, transforming a greenhouse gas into a valuable fuel. However, achieving high selectivity toward CH 4 , particularly at high current densities, remains a significant challenge. In this study, a remarkable Faradaic efficiency for CH 4 (FE CH4 ) of 88.7% with a current density of 461.0 mA cm −2 was achieved at −1.3 V vs. RHE over CuCeSiO x electrode in a ternary electrolyte of 1 M tetrapropylammonium hydroxide (TPAOH) + 5 mM KCl, setting a new record for CO 2 electroreduction to CH 4 . By employing other Cu‐based catalysts, high CH 4 selectivity can also be obtained in this ternary electrolyte. Mechanistic studies reveal the synergistic effect of mixed K + and TPA + in the electrochemical double layer plays a critical role in controlling the reaction pathway. Specifically, K + modulates *CO adsorption and promotes water dissociation, generating abundant H • radicals, while TPA + aggregates stabilize these radicals, accelerating the reaction kinetics, and facilitating the deep hydrogenation from *CO to CH 4 .
Article Details
Authors (16)
Meng Zhou
Yiyong Wang
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Centre for Excellence in Molecular Sciences, Centre for Carbon Neutral Chemistry
Shiqiang Liu
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Centre for Excellence in Molecular Sciences, Centre for Carbon Neutral Chemistry
Yaoyu Yin
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Centre for Excellence in Molecular Sciences, Centre for Carbon Neutral Chemistry
Yaguang Peng
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Centre for Excellence in Molecular Sciences, Centre for Carbon Neutral Chemistry
Jiapeng Jiao
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, State Key Laboratory of Petroleum Molecular & Process Engineering, School of Chemistry and Molecular Engineering
Jiahao Yang
Xiamen University , , ,
Wengling Zhao
Beijing National Laboratory for Molecular Sciences CAS Laboratory of Colloid and Interface and Thermodynamics CAS Research/Education Center for Excellence in Molecular Sciences Center for Carbon Neutral Chemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
Hengan Wang
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Centre for Excellence in Molecular Sciences, Centre for Carbon Neutral Chemistry
Ran Duan
Qinggong Zhu
Institute of Chemistry, Chinese Academy of Sciences , , ,
Xiaofu Sun
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Yi Xu
Jianling Zhang
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Xinchen Kang
Institute of Chemistry, Chinese Academy of Sciences , , ,
Buxing Han
Institute of Chemistry, Chinese Academy of Sciences , , ,