Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 5, 2018 | Published + Supplemental Material
Journal Article Open

Synergy between Fe and Ni in the optimal performance of (Ni,Fe)OOH catalysts for the oxygen evolution reaction


The oxygen evolution reaction (OER) is critical to solar production of fuels, but the reaction mechanism underlying the performance for a best OER catalyst, Fe-doped NiOOH [(Ni,Fe)OOH], remains highly controversial. We used grand canonical quantum mechanics to predict the OER mechanisms including kinetics and thus overpotentials as a function of Fe content in (Ni,Fe)OOH catalysts. We find that density functional theory (DFT) without exact exchange predicts that addition of Fe does not reduce the overpotential much. However, DFT with exact exchange predicts dramatic improvement in performance for (Ni,Fe)OOH, leading to an overpotential of 0.42 V and a Tafel slope of 23 mV/decade (dec), in good agreement with experiments, 0.3–0.4 V and 30 mV/dec. We reveal that the high spin d^4 Fe(IV) leads to efficient formation of an active O radical intermediate, while the closed shell d^6 Ni(IV) catalyzes the subsequent O–O coupling, and thus it is the synergy between Fe and Ni that delivers the optimal performance for OER.

Additional Information

© 2018 National Academy of Sciences. Published under the PNAS license. Contributed by William A. Goddard III, April 14, 2018 (sent for review December 18, 2017; reviewed by Daniel G. Nocera and Annabella Selloni) PNAS May 21, 2018. 201722034; published ahead of print May 21, 2018. https://doi.org/10.1073/pnas.1722034115 This work 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 DOE under Award DE-SC0004993. The calculations were carried out on the Extreme Science and Engineering Discovery Environment, which is supported by National Science Foundation Grant ACI-1053575, and the Zwicky Astrophysics Supercomputer at Caltech. Author contributions: H.X. and W.A.G. designed research; H.X. and H.S. performed research; H.X. and H.S. analyzed data; and H.X. and W.A.G. wrote the paper. Reviewers: D.G.N., Harvard University; and A.S., Princeton University. The authors declare no conflict of interest. This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1722034115/-/DCSupplemental.

Attached Files

Published - 5872.full.pdf

Supplemental Material - pnas.1722034115.sapp.pdf


Files (2.0 MB)
Name Size Download all
870.5 kB Preview Download
1.2 MB Preview Download

Additional details

August 21, 2023
October 18, 2023