Selective CO₂ Electrochemical Reduction Enabled by a Tricomponent Copolymer Modifier on a Copper Surface
Jianchun Wang, Tao Cheng, Aidan Q. Fenwick, Turki N. Baroud, Alonso Rosas-Hernández, Jeong Hoon Ko, Quan Gan, William A. Goddard III, Robert H. Grubbs
Abstract
Electrochemical CO₂ reduction over Cu could provide value-added multicarbon hydrocarbons and alcohols. Despite recent breakthroughs, it remains a significant challenge to design a catalytic system with high product selectivity. Here we demonstrate that a high selectivity of ethylene (55%) and C₂₊ products (77%) could be achieved by a highly modular tricomponent copolymer modified Cu electrode, rivaling the best performance using other modified polycrystalline Cu foil catalysts. Such a copolymer can be conveniently prepared by a ring-opening metathesis polymerization, thereby offering a new degree of freedom for tuning the selectivity. Control experiments indicate all three components are essential for the selectivity enhancement. A surface characterization showed that the incorporation of a phenylpyridinium component increased the film robustness against delamination. It was also shown that its superior performance is not due to a morphology change of the Cu underneath. Molecular dynamics (MD) simulations indicate that a combination of increased local CO₂ concentration, increased porosity for gas diffusion, and the local electric field effect together contribute to the increased ethylene and C₂₊ product selectivity.
Group Members
Wang, J., Cheng, T., Fenwick, A. Q., Baroud, T. N., Rosas-Hernández, A., Ko, J. H., Gan, Q., III, W. A. G., & Grubbs, R. H. (2021). Selective CO₂ Electrochemical Reduction Enabled by a Tricomponent Copolymer Modifier on a Copper Surface. *J. Am. Chem. Soc.*, *143*(7), 2857-2865. https://doi.org/10.1021/jacs.0c12478