Promoting CO2 methanation via ligand-stabilized metal oxide clusters as hydrogen-donating motifs
Yuhang Li, Aoni Xu, Yanwei Lum, Xue Wang, Sung‐Fu Hung, Bin Chen, Ziyun Wang, Yi Xu, Fengwang Li, Jehad Abed, Jianan Erick Huang, Armin Sedighian Rasouli, Joshua Wicks, Laxmi Kishore Sagar, Tao Peng, Alexander H. Ip, David Sinton, Hao Jiang, Chunzhong Li, Edward H. Sargent
Abstract
Electroreduction uses renewable energy to upgrade carbon dioxide to value-added chemicals and fuels. Renewable methane synthesized using such a route stands to be readily deployed using existing infrastructure for the distribution and utilization of natural gas. Here we design a suite of ligand-stabilized metal oxide clusters and find that these modulate carbon dioxide reduction pathways on a copper catalyst, enabling thereby a record activity for methane electroproduction. Density functional theory calculations show adsorbed hydrogen donation from clusters to copper active sites for the *CO hydrogenation pathway towards *CHO. We promote this effect via control over cluster size and composition and demonstrate the effect on metal oxides including cobalt(II), molybdenum(VI), tungsten(VI), nickel(II) and palladium(II) oxides. We report a carbon dioxide-to-methane faradaic efficiency of 60% at a partial current density to methane of 135 milliampere per square centimetre. We showcase operation over 18 h that retains a faradaic efficiency exceeding 55%.