Efficient electrocatalysts for the oxygen evolution reaction (OER) are paramount to the development of electrochemical devices for clean energy and fuel conversion. However, the structural complexity of heterogeneous electrocatalysts makes it a great challenge to elucidate the surface catalytic sites and OER mechanisms. Here, we report that catalytic single-site Co in a well-defined brookite TiO2 nanorod (210) surface (Co-TiO2) presents turnover frequencies that are among the highest for Co-based heterogeneous catalysts reported to date, reaching 6.6 ± 1.2 and 181.4 ± 28 s−1 at 300 and 400 mV overpotentials, respectively. Based on grand canonical quantum mechanics calculations and the single-site Co atomic structure validated by in situ and ex situ spectroscopic probes, we have established a full description of the catalytic reaction kinetics for Co-TiO2 as a function of applied potential, revealing an adsorbate evolution mechanism for the OER. The computationally predicted Tafel slope and turnover frequencies exhibit exceedingly good agreement with experiment.
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All data generated or analysed during this study are included in this published article (and its Supplementary Information files) or can be obtained from the corresponding authors upon reasonable request.
All computational structures are included in this published article (and its Supplementary Data and Supplementary Information files). The code and script for GCQM computation and analysis are provided as part of the jDFTx constant charge calculations and can be accessed at https://jdftx.org/index.html or obtained from the corresponding authors upon reasonable request.
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This work was supported by the US National Science Foundation (CBET-1805022, CBET-2004808 and CBET-2005250). This research used the resources of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by the Argonne National Laboratory, and was supported by the US DOE under contract no. DE-AC02-06CH11357 and the Canadian Light Source and its funding partners. This research used the resources of the Center for Functional Nanomaterials, which is a US DOE Office of Science Facility, at Brookhaven National Laboratory under contract no. DE-SC0012704. This research used the resources of the Advanced Light Source, a US DOE Office of Science User Facility, under contract no. DE-AC02-05CH11231.
The authors declare no competing interests.
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Liu, C., Qian, J., Ye, Y. et al. Oxygen evolution reaction over catalytic single-site Co in a well-defined brookite TiO2 nanorod surface. Nat Catal 4, 36–45 (2021). https://doi.org/10.1038/s41929-020-00550-5