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Theory-driven design of high-valence metal sites for water oxidation confirmed using in situ soft X-ray absorption


The efficiency with which renewable fuels and feedstocks are synthesized from electrical sources is limited at present by the sluggish oxygen evolution reaction (OER) in pH-neutral media. We took the view that generating transition-metal sites with high valence at low applied bias should improve the activity of neutral OER catalysts. Here, using density functional theory, we find that the formation energy of desired Ni4+ sites is systematically modulated by incorporating judicious combinations of Co, Fe and non-metal P. We therefore synthesized NiCoFeP oxyhydroxides and probed their oxidation kinetics with in situ soft X-ray absorption spectroscopy (sXAS). In situ sXAS studies of neutral-pH OER catalysts indicate ready promotion of Ni4+ under low overpotential conditions. The NiCoFeP catalyst outperforms IrO2 and retains its performance following 100 h of operation. We showcase NiCoFeP in a membrane-free CO2 electroreduction system that achieves a 1.99 V cell voltage at 10 mA cm–2, reducing CO2 into CO and oxidizing H2O to O2 with a 64% electricity-to-chemical-fuel efficiency.

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Figure 1: Change in Gibbs free energies for Ni2+→Ni3+→Ni4+.
Figure 2: An in situ electrochemical flow cell, enabling in situ sXAS.
Figure 3: Performance of NiCoFeP oxyhydroxides catalysts and controls in a three-electrode configuration in CO2-saturated 0.5 M KHCO3 aqueous electrolyte.


  1. 1

    Lin, S. et al. Covalent organic frameworks comprising cobalt porphyrins for catalytic CO2 reduction in water. Science 349, 1208–1213 (2015).

    CAS  PubMed  Google Scholar 

  2. 2

    Goeppert, A., Czaun, M., Jones, J. P., Surya Prakash, G. K. & Olah, G. A. Recycling of carbon dioxide to methanol and derived products—closing the loop. Chem. Soc. Rev. 43, 7995–8048 (2014).

    CAS  PubMed  Google Scholar 

  3. 3

    Schreier, M. et al. Efficient photosynthesis of carbon monoxide from CO2 using perovskite photovoltaics. Nat. Commun. 6, 7326 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. 4

    Costentin, C., Drouet, S., Robert, M. & Saveant, J. M. A local proton source enhances CO2 electroreduction to CO by a molecular Fe catalyst. Science 338, 90–94 (2012).

    CAS  PubMed  Google Scholar 

  5. 5

    Bediako, D. K. et al. Structure–activity correlations in a nickel-borate oxygen evolution catalyst. J. Am. Chem. Soc. 134, 6801–6809 (2012).

    CAS  PubMed  Google Scholar 

  6. 6

    Kanan, M. W. & Nocera, D. G. In situ formation of an oxygen-evolving catalyst in neutral water containing phosphate and Co2+. Science 321, 1072–1075 (2008).

    CAS  PubMed  Google Scholar 

  7. 7

    Joya, K. S., Joya, Y. F. & de Groot, H. J. M. Ni-based electrocatalyst for water oxidation developed in-situ in a HCO3/CO2 system at near-neutral pH. Adv. Energy Mater. 4, 1301929 (2014).

    Google Scholar 

  8. 8

    Vargas-Barbosa, N. M., Geise, G. M., Hickner, M. A. & Mallouk, T. E. Assessing the utility of bipolar membranes for use in photoelectrochemical water-splitting cells. ChemSusChem 7, 3017–3020 (2014).

    CAS  PubMed  Google Scholar 

  9. 9

    Hernández-Pagán, E. A. et al. Resistance and polarization losses in aqueous buffer–membrane electrolytes for water-splitting photoelectrochemical cells. Energy Environ. Sci. 5, 7582–7589 (2012).

    Google Scholar 

  10. 10

    Chen, J. Y. et al. Operando analysis of NiFe and Fe oxyhydroxide electrocatalysts for water oxidation: detection of Fe4+ by Mossbauer spectroscopy. J. Am. Chem. Soc. 137, 15090–15093 (2015).

    CAS  PubMed  Google Scholar 

  11. 11

    Bergmann, A. et al. Reversible amorphization and the catalytically active state of crystalline Co3O4 during oxygen evolution. Nat. Commun. 6, 8625 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  12. 12

    Bediako, D. K., Surendranath, Y. & Nocera, D. G. Mechanistic studies of the oxygen evolution reaction mediated by a nickel-borate thin film electrocatalyst. J. Am. Chem. Soc. 135, 3662–3674 (2013).

    CAS  PubMed  Google Scholar 

  13. 13

    Zaffran, J. & Toroker, M. C. Designing efficient doped NiOOH catalysts for water splitting with first principles calculations. ChemistrySelect 1, 911–916 (2016).

    CAS  Google Scholar 

  14. 14

    Zaffran, J. & Toroker, M. C. Benchmarking density functional theory based methods to model NiOOH material properties: Hubbard and van der Waals corrections vs hybrid functionals. J. Chem. Theory. Comput. 12, 3807–3812 (2016).

    CAS  PubMed  Google Scholar 

  15. 15

    Li, N ., Bediako, D. K., Hadt, R. G. et al. Influence of iron doping on tetravalent nickel content in catalytic oxygen evolving films. Proc. Natl Acad. Sci. USA 114, 1486–1491 (2017).

    CAS  PubMed  Google Scholar 

  16. 16

    Bajdich, M., Garcia-Mota, M., Vojvodic, A., Norskov, J. K. & Bell, A. T. Theoretical investigation of the activity of cobalt oxides for the electrochemical oxidation of water. J. Am. Chem. Soc. 135, 13521–13530 (2013).

    CAS  PubMed  Google Scholar 

  17. 17

    Persson, K. A., Waldwick, B., Lazic, P. & Ceder, G. Prediction of solid-aqueous equilibria: scheme to combine first-principles calculations of solids with experimental aqueous states. Phy. Rev. B 85, 235438 (2012).

    Google Scholar 

  18. 18

    Smith, R. D. & Berlinguette, C. P. Accounting for the dynamic oxidative behavior of nickel anodes. J. Am. Chem. Soc. 138, 1561–1567 (2016).

    CAS  PubMed  Google Scholar 

  19. 19

    Zhang, B. et al. Homogeneously dispersed, multimetal oxygen-evolving catalysts. Science 352, 6283–6288 (2016).

    Google Scholar 

  20. 20

    Gong, M. et al. An advanced Ni-Fe layered double hydroxide electrocatalyst for water oxidation. J. Am. Chem. Soc. 135, 8452–8455 (2013).

    CAS  PubMed  Google Scholar 

  21. 21

    Diaz-Morales, O., Ledezma-Yanez, I., Koper, M. T. M. & Calle-Vallejo, F. Guidelines for the rational design of Ni-based double hydroxide electrocatalysts for the oxygen evolution reaction. ACS Catal. 5, 5380–5387 (2015).

    CAS  Google Scholar 

  22. 22

    Wang, H. et al. Bifunctional non-noble metal oxide nanoparticle electrocatalysts through lithium-induced conversion for overall water splitting. Nat. Commun. 6, 7261 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  23. 23

    Suntivich, J., May, K. J., Gasteiger, H. A., Goodenough, J. B. & Shao-Horn, Y. A perovskite oxide optimized for oxygen evolution catalysis from molecular orbital principles. Science 334, 1383–1385 (2011).

    CAS  PubMed  Google Scholar 

  24. 24

    Favaro, M., Drisdell, W. S., Marcus, M. A. et al. An operando investigation of (Ni–Fe–Co–Ce) Ox system as highly efficient electrocatalyst for oxygen evolution reaction. ACS Catal. 7, 1248–1258 (2017).

    CAS  Google Scholar 

  25. 25

    Diaz-Morales, O., Ferrus-Suspedra, D. & Koper, M. T. M. The importance of nickel oxyhydroxide deprotonation on its activity towards electrochemical water oxidation. Chem. Sci. 7, 2639–2645 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  26. 26

    Kanan, M. W., Surendranath, Y. & Nocera, D. G. Cobalt-phosphate oxygen-evolving compound. Chem. Soc. Rev. 38, 109–114 (2009).

    CAS  PubMed  Google Scholar 

  27. 27

    Tkalych, A. J., Yu, K. & Carter, E. A. Structural and electronic features of β-Ni(OH)2 and β-NiOOH from first principles. J. Phys. Chem. C 119, 24315–24322 (2015).

    CAS  Google Scholar 

  28. 28

    Carpenter, M. K. & Corrigan, D. A. Photoelectrochemistry of nickel-hydroxide thin-films. J. Electrochem. Soc. 136, 1022–1026 (1989).

    CAS  Google Scholar 

  29. 29

    Friebel, D. et al. Identification of highly active Fe sites in (Ni,Fe)OOH for electrocatalytic water splitting. J. Am. Chem. Soc. 137, 1305–1313 (2015).

    CAS  PubMed  Google Scholar 

  30. 30

    Vinson, J. & Rehr, J. J. Ab initio Bethe–Salpeter calculations of the X-ray absorption spectra of transition metals at the L-shell edges. Phys. Rev. B 86, 195135 (2012).

    Google Scholar 

  31. 31

    Deb, A., Bergmann, U., Cramer, S. P. & Cairns, E. J. Local structure of LiNi0.5Mn0.5O2 cathode material probed by in situ X-ray absorption spectroscopy. J. Appl. Phys. 99, 063701 (2006).

    Google Scholar 

  32. 32

    De Groot, F. M. F. et al. 1s2p resonant inelastic X-ray scattering of iron oxides. J. Phys. Chem. B 109, 20751–20762 (2005).

    CAS  PubMed  Google Scholar 

  33. 33

    Velasco-Velez, J. J. et al. The structure of interfacial water on gold electrodes studied by X-ray absorption spectroscopy. Science 346, 831–834 (2014).

    CAS  PubMed  Google Scholar 

  34. 34

    Van Veenendaal, M. A. & Sawatzky, G. A. Doping dependence of Ni 2p X-ray-absorption spectra of M xNi1−xO (M=Li,Na). Phys. Rev. B 50, 11326–11331 (1994).

    CAS  Google Scholar 

  35. 35

    Liu, X. et al. Distinct charge dynamics in battery electrodes revealed by in situ and operando soft X-ray spectroscopy. Nat. Commun. 4, 2568 (2013).

    PubMed  PubMed Central  Google Scholar 

  36. 36

    Van Elp, J., Eskes, H., Kuiper, P. & Sawatzky, G. A. Electronic structure of Li-doped NiO. Phys. Rev. B 45, 1612–1622 (1992).

    CAS  Google Scholar 

  37. 37

    Ralston, C. Y. et al. Characterization of heterogeneous nickel sites in CO dehydrogenases from Clostridium thermoaceticum and Rhodospirillum rubrum by nickel L-edge X-ray spectroscopy. J. Am. Chem. Soc. 122, 10553–10560 (2000).

    CAS  Google Scholar 

  38. 38

    Vinson, J., Rehr, J. J., Kas, J. J. & Shirley, E. L. Bethe–Salpeter equation calculations of core excitation spectra. Phys. Rev. B 83, 115106 (2011).

    Google Scholar 

  39. 39

    Gilmore, K. et al. Efficient implementation of core-excitation Bethe–Salpeter equation calculations. Comput. Phys. Commun. 197, 109–117 (2015).

    CAS  Google Scholar 

  40. 40

    Vinson, J., Kas, J. J., Vila, F. D., Rehr, J. J. & Shirley, E. L. Theoretical optical and X-ray spectra of liquid and solid H2O. Phys. Rev. B 85, 045101 (2012).

    Google Scholar 

  41. 41

    Stavistki, E. & de Groot, F. M. F. The CTM4XAS program for EELS and XAS spectral shape analysis of transition metal L edges. Micron 41, 687–694 (2010).

    Google Scholar 

  42. 42

    Haverkort, M. W., Zwierzycki, M. & Andersen, O. K. Multiplet ligand-field theory using Wannier orbitals. Phys. Rev. B 85, 165113 (2012).

    Google Scholar 

  43. 43

    Yamaguchi, A. et al. Regulating proton-coupled electron transfer for efficient water splitting by manganese oxides at neutral pH. Nat. Commun. 5, 4256–4266 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  44. 44

    Liu, M. et al. Enhanced electrocatalytic CO2 reduction via field-induced reagent concentration. Nature 537, 382–386 (2016).

    CAS  PubMed  Google Scholar 

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This work was supported by the Ontario Research Fund Research Excellence Program, NSERC and the CIFAR Bio-Inspired Solar Energy programme. X.Z. acknowledges a scholarship from the China Scholarship Council (CSC) (20140625004) and the National Basic Research Program of China (2014CB931703). B.Z. acknowledges funding from STCSM (16JC1400702 and 14ZR14110200), NSFC (21503079) and the China Scholarship Council/University of Toronto Joint Funding Program (201406745001). This work has also benefited from SGM beamlines at the Canadian Light Source (CLS) and 4B9B and 4B7A beamlines at Beijing Synchrotron Radiation Facility. The CLS is supported by the Natural Sciences and Engineering Research Council of Canada, the National Research Council Canada, the Canadian Institutes of Health Research, the Province of Saskatchewan, Western Economic Diversification Canada and the University of Saskatchewan. The authors thank J. Guo and L. Zhang from Advanced Light Source for soft X-ray absorption measurements. The TEM study in this work was supported by the Center for Functional Nanomaterials, which is a US DOE Office of Science Facility at Brookhaven National Laboratory, under contract no. DE-SC0012704. First-principles simulations of X-ray absorption spectroscopy and associated interpretation and consultation by Y.L. and D.P. are provided through a user project at The Molecular Foundry (TMF), including use of its computer cluster (vulcan), managed by the High Performance Computing Services Group, at Lawrence Berkeley National Laboratory (LBNL), and associated use of TMF computing resources at the National Energy Research Scientific Computing Center (NERSC), LBNL. TMF and NERSC are US DOE User Facilities, both supported by the Office of Science of the US DOE under contract no. DE-AC02-05CH11231. DFT computations were performed using the IBM BlueGene/Q supercomputer at the SciNet HPC Consortium provided through the Southern Ontario Smart Computing Innovation Platform (SOSCIP).

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E.H.S., D.P. and B.Z. supervised the project. X.Z. and B.Z. designed and carried out the experiments. X.Z., B.Z., T.R., J.D. and R.C. performed the soft X-ray measurements. P.D.L., Y.L., D.P. and O.V. carried out simulations. L.H., H.L.X. and X.D. performed TEM measurements. X.Z., B.Z., F.P.C.d.A., M.L., C.T.D., S.H. and H.P. performed electrochemical measurements. All authors discussed the results and assisted during manuscript preparation.

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Correspondence to Bo Zhang or Edward H. Sargent.

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Zheng, X., Zhang, B., De Luna, P. et al. Theory-driven design of high-valence metal sites for water oxidation confirmed using in situ soft X-ray absorption. Nature Chem 10, 149–154 (2018).

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