Cu metal embedded in oxidized matrix catalyst to promote CO₂ activation and CO dimerization for electrochemical reduction of CO₂
We propose and validate with quantum mechanics methods a unique catalyst for electrochemical reduction of CO₂ (CO₂RR) in which selectivity and activity of CO and C₂ products are both enhanced at the borders of oxidized and metallic surface regions. This Cu metal embedded in oxidized matrix (MEOM) catalyst is consistent with observations that Cu₂O-based electrodes improve performance. However, we show that a fully oxidized matrix (FOM) model would not explain the experimentally observed performance boost, and we show that the FOM is not stable under CO₂ reduction conditions. This electrostatic tension between the Cu⁺ and Cu⁰ surface sites responsible for the MEOM mechanism suggests a unique strategy for designing more efficient and selective electrocatalysts for CO₂RR to valuable chemicals (HCOₓ), a critical need for practical environmental and energy applications.
© 2017 National Academy of Sciences. Freely available online through the PNAS open access option. Contributed by William A. Goddard III, May 9, 2017 (sent for review February 13, 2017; reviewed by Timo Jacob and Bruce Parkinson). This research was supported by the Joint Center for Artificial Photosynthesis, a Department of Energy (DOE) Energy Innovation Hub, supported through the Office of Science of the US DOE under Award DE-SC0004993. This work used the computational resources of Zwicky (at California Institute of Technology). Author contributions: H.X. and W.A.G. designed research; H.X. and T.C. performed research; H.X., W.A.G., T.C., and Y.L. analyzed data; and H.X. and W.A.G. wrote the paper. Reviewers: T.J., Universität Ulm; and B.P., University of Wyoming. The authors declare no conflict of interest. This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1702405114/-/DCSupplemental.
Published - PNAS-2017-Xiao-6685-8.pdf
Supplemental Material - pnas.201702405SI.pdf