Low coordination number copper catalysts for electrochemical CO2 methanation in a membrane electrode assembly

Yi Xu, Fengwang Li, Aoni Xu, Jonathan P. Edwards, Sung-Fu Hung, Christine M. Gabardo, Colin P. O'Brien, Shijie Liu, Xue Wang, Yuhang Li, Joshua Wicks, Rui Kai Miao (+7 others)
2021 Nature Communications  
AbstractThe electrochemical conversion of CO2 to methane provides a means to store intermittent renewable electricity in the form of a carbon-neutral hydrocarbon fuel that benefits from an established global distribution network. The stability and selectivity of reported approaches reside below technoeconomic-related requirements. Membrane electrode assembly-based reactors offer a known path to stability; however, highly alkaline conditions on the cathode favour C-C coupling and multi-carbon
more » ... ducts. In computational studies herein, we find that copper in a low coordination number favours methane even under highly alkaline conditions. Experimentally, we develop a carbon nanoparticle moderator strategy that confines a copper-complex catalyst when employed in a membrane electrode assembly. In-situ XAS measurements confirm that increased carbon nanoparticle loadings can reduce the metallic copper coordination number. At a copper coordination number of 4.2 we demonstrate a CO2-to-methane selectivity of 62%, a methane partial current density of 136 mA cm−2, and > 110 hours of stable operation.
doi:10.1038/s41467-021-23065-4 pmid:34006871 fatcat:asj5psmlsndcxbspxdc7fvyprm