Copper–Carbon Bond Metal–Organic Frameworks for Highly Efficient and Stable CO<sub>2</sub> Electrochemical Methanation
Shuaiqiang Jia, Qinggong Zhu, Xiao Chen, Cheng Xue, Mengke Dong, Ting Deng, Hailian Cheng, Ting Yao, Jiapeng Jiao, Zhanghui Xia, Jianrong Zeng, Chunjun Chen, Haihong Wu, Mingyuan He, Buxing Han
Abstract
Cu-based metal–organic frameworks (Cu-MOFs) integrate the high tunability of molecular systems with the high activity of metal sites, making them promising electrocatalysts for the electrocatalytic reduction of carbon dioxide (CO 2 RR). To date, the primary challenge in the application of Cu-MOFs in electrocatalytic CO 2 RR is their poor stability during the reduction process. Herein, we pursue experimental and theoretical insights into Cu-C MOFs for the CO 2 RR for the first time. Notably, Cu-TEPT, a Cu-C MOF synthesized through the reaction of tetrakis(acetonitrile)copper(I) Trifluoromethanesulfonate with 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine (TEPT) ligand, exhibited remarkable activity toward methane (CH 4 ) production. It achieved a high Faradaic efficiency (FE) of 83.6% and a CH 4 partial current density of up to 295.4 mA cm –2, marking one of the highest performances reported to date. Experimental and theoretical studies indicated that the outstanding CO 2 RR performance and stability of Cu-TEPT result from the ligand-protected alkynyl Cu(I) sites in Cu-TEPT, which effectively stabilize the Cu + sites and accelerate the kinetics of CO 2 to CH 4 .