Electrocatalytic Methane Oxidation Greatly Promoted by Chlorine Intermediates
Qihao Wang, Tengfei Li, Chao Yang, Menghuan Chen, Anxiang Guan, Li Yang, Si Li, Ximeng Lv, Yuhang Wang, Gengfeng Zheng
Abstract
Abstract Renewable energy‐powered methane (CH 4 ) conversion at ambient conditions is an attractive but highly challenging field. Due to the highly inert character of CH 4 , the selective cleavage of its first C−H bond without over‐oxidation is essential for transforming CH 4 into value‐added products. In this work, we developed an efficient and selective CH 4 conversion approach at room temperature using intermediate chlorine species (*Cl), which were electrochemically generated and stabilized on mixed cobalt–nickel spinels with different Co/Ni ratios. The lower overpotentials for *Cl formation enabled an effective activation and conversion of CH 4 to CH 3 Cl without over‐oxidation to CO 2 , and Ni 3+ at the octahedral sites in the mixed cobalt–nickel spinels allowed to stabilize surface‐bound *Cl species. The CoNi 2 O x electrocatalyst exhibited an outstanding yield of CH 3 Cl (364 mmol g −1 h −1 ) and a high CH 3 Cl/CO 2 selectivity of over 400 at room temperature, with demonstrated capability of direct CH 4 conversion under seawater working conditions.