Abstract
The rational design of hydrogen evolution reaction electrocatalysts that can compete with platinum is an outstanding challenge in the process of designing viable power-to-gas technologies. Here, we introduce delafossites as a family of hydrogen evolution reaction electrocatalysts in acidic media. We show that, in PdCoO2, the inherently strained Pd metal sublattice acts as a pseudomorphic template for the growth of a tensile-strained Pd-rich capping layer under reductive conditions. The surface modification ranges up to 400 nm and continuously improves the electrocatalytic activity by simultaneously increasing the exchange current density and by reducing the Tafel slope down to 38 mV dec−1, leading to overpotentials η10 < 15 mV. The improved activity is attributed to the operando stabilization of a β-PdHx phase with enhanced surface catalytic properties with respect to pure or nanostructured palladium. These findings illustrate how operando-induced electrodissolution can be used as a top-down design concept through the strain-stabilized formation of catalytically active phases.
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The data supporting the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
References
Lewis, N. S. & Nocera, D. G. Powering the planet: chemical challenges in solar energy utilization. Proc. Natl Acad. Sci. USA 103, 15729–15735 (2006).
Lewis, N. S. Toward cost-effective solar energy use. Science 315, 798–801 (2007).
Podjaski, F., Kröger, J. & Lotsch, B. V. Toward an aqueous solar battery: direct electrochemical storage of solar energy in carbon nitrides. Adv. Mater. 30, 1705477 (2018).
Yu, M. Z. et al. Solar-powered electrochemical energy storage: an alternative to solar fuels. J. Mater. Chem. A 4, 2766–2782 (2016).
Gülzow, E. Alkaline fuel cells: a critical view. J. Power Sources 61, 99–104 (1996).
Tobias, R., Nhan, N. H., Detre, T., Robert, S. & Peter, S. Electrocatalytic oxygen evolution reaction in acidic environments—reaction mechanisms and catalysts. Adv. Energy Mater. 7, 1601275 (2017).
Carmo, M., Fritz, D. L., Mergel, J. & Stolten, D. A comprehensive review on PEM water electrolysis. Int. J. Hydrog. Energy 38, 4901–4934 (2013).
Vesborg, P. C. K. & Jaramillo, T. F. Addressing the terawatt challenge: scalability in the supply of chemical elements for renewable energy. RSC Adv. 2, 7933–7947 (2012).
Shao, M. Electrocatalysis in Fuel Cells (Springer, 2013).
Papageorgopoulos, D. C., Keijzer, M., Veldhuis, J. B. J. & de Bruijn, F. A. CO tolerance of Pd-rich platinum palladium carbon-supported electrocatalysts—proton exchange membrane fuel cell applications. J. Electrochem. Soc. 149, A1400–A1404 (2002).
Mavrikakis, M., Hammer, B. & Nørskov, J. K. Effect of strain on the reactivity of metal surfaces. Phys. Rev. Lett. 81, 2819–2822 (1998).
Kibler, L. A., El-Aziz, A. M., Hoyer, R. & Kolb, D. M. Tuning reaction rates by lateral strain in a palladium monolayer. Angew. Chem. Int. Ed. 44, 2080–2084 (2005).
Greeley, J., Jaramillo, T. F., Bonde, J., Chorkendorff, I. & Nørskov, J. K. Computational high-throughput screening of electrocatalytic materials for hydrogen evolution. Nat. Mater. 5, 909–913 (2006).
Strasser, P. et al. Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts. Nat. Chem. 2, 454–460 (2010).
Du, M., Cui, L., Cao, Y. & Bard, A. J. Mechanoelectrochemical catalysis of the effect of elastic strain on a platinum nanofilm for the ORR exerted by a shape memory alloy substrate. J. Am. Chem. Soc. 137, 7397–7403 (2015).
Putungan, D. B., Lin, S.-H. & Kuo, J.-L. A first-principles examination of conducting monolayer 1T′-MX2 (M = Mo, W; X = S, Se, Te): promising catalysts for hydrogen evolution reaction and its enhancement by strain. Phys. Chem. Chem. Phys. 17, 21702–21708 (2015).
Escudero-Escribano, M. et al. Tuning the activity of Pt alloy electrocatalysts by means of the lanthanide contraction. Science 352, 73–76 (2016).
Wang, H. et al. Direct and continuous strain control of catalysts with tunable battery electrode materials. Science 354, 1031–1036 (2016).
Luo, M. & Guo, S. Strain-controlled electrocatalysis on multimetallic nanomaterials. Nat. Rev. Mater. 2, 17059 (2017).
Shannon, R. D., Rogers, D. B. & Prewitt, C. T. Chemistry of noble metal oxides. I. Syntheses and properties of ABO2 delafossite compounds. Inorg. Chem. 10, 713–718 (1971).
Prewitt, C. T., Shannon, R. D. & Rogers, D. B. Chemistry of noble metal oxides. II. Crystal structures of PtCoO2, PdCoO2, CuFeO2, and AgFeO2. Inorg. Chem. 10, 719–723 (1971).
Rogers, D. B., Shannon, R. D., Prewitt, C. T. & Gillson, J. L. Chemistry of noble metal oxides. III. Electrical transport properties and crystal chemistry of ABO2 compounds with delafossite structure. Inorg. Chem. 10, 723–727 (1971).
Daou, R., Frésard, R., Eyert, V., Hébert, S. & Maignan, A. Unconventional aspects of electronic transport in delafossite oxides. Sci. Technol. Adv. Mater. 18, 919–938 (2017).
Ong, K. P., Singh, D. J. & Wu, P. Unusual transport and strongly anisotropic thermopower in PtCoO2 and PdCoO2. Phys. Rev. Lett. 104, 176601 (2010).
Moll, P. J. W., Kushwaha, P., Nandi, N., Schmidt, B. & Mackenzie, A. P. Evidence for hydrodynamic electron flow in PdCoO2. Science 351, 1061–1064 (2016).
Carcia, P. F., Shannon, R. D., Bierstedt, P. E. & Flippen, R. B. O2 electrocatalysis on thin-film metallic oxide electrodes with the delafossite structure. J. Electrochem. Soc. 127, 1974–1978 (1980).
Toyoda, K., Hinogami, R., Miyata, N. & Aizawa, M. Calculated descriptors of catalytic activity for water electrolysis anode: application to delafossite oxides. J. Phys. Chem. C 119, 6495–6501 (2015).
Gu, J. et al. p-Type CuRhO2 as a self-healing photoelectrode for water reduction under visible light. J. Am. Chem. Soc. 136, 830–833 (2014).
Prévot, M. S. et al. Evaluating charge carrier transport and surface states in CuFeO2 photocathodes. Chem. Mater. 29, 4952–4962 (2017).
Varga, A., Samu, G. F. & Janáky, C. Rapid synthesis of interconnected CuCrO2 nanostructures: a promising electrode material for photoelectrochemical fuel generation. Electrochim. Acta 272, 22–32 (2018).
Ahmed, J. & Mao, Y. B. Delafossite CuAlO2 nanoparticles with electrocatalytic activity toward oxygen and hydrogen evolution reactions. Nanomater. Sustain. Energy 1213, 57–72 (2015).
Díaz-García, A. K., Lana-Villarreal, T. & Gómez, R. Sol–gel copper chromium delafossite thin films as stable oxide photocathodes for water splitting. J. Mater. Chem. A 3, 19683–19687 (2015).
Park, J. E. et al. Stable hydrogen evolution from an AgRhO2 photocathode under visible light. Chem. Mater. 30, 2574–2582 (2018).
Duncan, H. & Lasia, A. Separation of hydrogen adsorption and absorption on Pd thin films. Electrochim. Acta 53, 6845–6850 (2008).
Tanaka, M., Hasegawa, M. & Takei, H. Crystal growth of PdCoO2, PtCoO2 and their solid-solution with delafossite structure. J. Cryst. Growth 173, 440–445 (1997).
Morales-Guio, C. G., Stern, L.-A. & Hu, X. Nanostructured hydrotreating catalysts for electrochemical hydrogen evolution. Chem. Soc. Rev. 43, 6555–6569 (2014).
McCrory, C. C. L. et al. Benchmarking hydrogen evolving reaction and oxygen evolving reaction electrocatalysts for solar water splitting devices. J. Am. Chem. Soc. 137, 4347–4357 (2015).
Cherevko, S. et al. Oxygen and hydrogen evolution reactions on Ru, RuO2, Ir, and IrO2 thin film electrodes in acidic and alkaline electrolytes: a comparative study on activity and stability. Catal. Today 262, 170–180 (2016).
Awaludin, Z., Safuan, M., Okajima, T. & Ohsaka, T. Investigating the physical and electrochemical effects of cathodic polarization treatment on TaOx. J. Mater. Chem. A 3, 16791–16800 (2015).
Campari, M., Taveres, A. C. & Trasatti, S. Thermally prepared Ti/RhOx electrodes: II H2 evolution in acid solution. Hem. Ind. 56, 231–237 (2002).
Shinagawa, T., Garcia-Esparza, A. T. & Takanabe, K. Insight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion. Sci. Rep. 5, 13801 (2015).
Maoka, T. & Enyo, M. Overpotential decay transients and the reaction mechanism on the Pd–H2 electrode. Surf. Technol. 8, 441–450 (1979).
Pentland, N., Bockris, J. O. & Sheldon, E. Hydrogen evolution reaction on copper, gold, molybdenum, palladium, rhodium, and iron—mechanism and measurement technique under high purity conditions. J. Electrochem. Soc. 104, 182–194 (1957).
Searson, P. C. Hydrogen evolution and entry in palladium at high current density. Acta Metall. Mater. 39, 2519–2525 (1991).
Elam, M. & Conway, B. E. Sorption behavior of the overpotential‐deposited H species in the cathodic H2 evolution reaction at Pd and Pt–Pd electroplated composite electrodes. J. Electrochem. Soc. 135, 1678–1685 (1988).
Jana, R., Bhim, A., Bothra, P., Pati, S. K. & Peter, S. C. Electrochemical dealloying of PdCu3 nanoparticles to achieve Pt-like activity for the hydrogen evolution reaction. ChemSusChem 9, 2922–2927 (2016).
Greeley, J., Nørskov, J. K., Kibler, L. A., El-Aziz, A. M. & Kolb, D. M. Hydrogen evolution over bimetallic systems: understanding the trends. ChemPhysChem 7, 1032–1035 (2006).
Lin, D. & Lasia, A. Electrochemical impedance study of the kinetics of hydrogen evolution at a rough palladium electrode in acidic solution. J. Electroanal. Chem. 785, 190–195 (2017).
Hollemann, A. F. & Wiberg, N. Lehrbuch der Anorganischen Chemie 102nd edn, 1387 (Walter de Gruyter, 2007).
Wagner, S. et al. Achieving coherent phase transition in palladium–hydrogen thin films. Scr. Mater. 64, 978–981 (2011).
Zhang, S. & Scheu, C. Evaluation of EELS spectrum imaging data by spectral components and factors from multivariate analysis. Microscopy 67, i133–i141 (2018).
Arblaster, J. W. Crystallographic properties of palladium assessment of properties from absolute zero to the melting point. Platinum Met. Rev. 56, 181–189 (2012).
Kuo, C.-H. et al. The effect of lattice strain on the catalytic properties of Pd nanocrystals. ChemSusChem 6, 1993–2000 (2013).
Kuhrt, C. & Anton, R. On the origin of a lattice expansion in palladium and Pd–Au vapour deposits on various substrates. Thin Solid Films 198, 301–315 (1991).
Teranishi, T. & Miyake, M. Size control of palladium nanoparticles and their crystal structures. Chem. Mater. 10, 594–600 (1998).
Dafft, E. G., Bohnenkamp, K. & Engell, H. J. Investigations of the electrochemical reduction of hydrogen ions on palladium electrodes. Z. Phys. Chem. 108, 33–44 (1977).
Hammer, B. & Norskov, J. K. Why gold is the noblest of all the metals. Nature 376, 238–240 (1995).
Nilsson, A. et al. The electronic structure effect in heterogeneous catalysis. Catal. Lett. 100, 111–114 (2005).
Gorzkowski, M. T. & Lewera, A. Probing the limits of d-band center theory: electronic and electrocatalytic properties of Pd-shell–Pt-core nanoparticles. J. Phys. Chem. C 119, 18389–18395 (2015).
Seh, Z. W. et al. Combining theory and experiment in electrocatalysis: insights into materials design. Science 355, eaad4998 (2017).
Adit Maark, T. & Peterson, A. A. Understanding strain and ligand effects in hydrogen evolution over Pd(111) surfaces. J. Phys. Chem. C 118, 4275–4281 (2014).
Mariano, R. G., McKelvey, K., White, H. S. & Kanan, M. W. Selective increase in CO2 electroreduction activity at grain-boundary surface terminations. Science 358, 1187–1192 (2017).
Hakamada, M., Nakano, H., Furukawa, T., Takahashi, M. & Mabuchi, M. Hydrogen storage properties of nanoporous palladium fabricated by dealloying. J. Phys. Chem. C 114, 868–873 (2010).
Zhou, H.-B., Jin, S., Zhang, Y., Lu, G.-H. & Liu, F. Anisotropic strain enhanced hydrogen solubility in bcc metals: the independence on the sign of strain. Phys. Rev. Lett. 109, 135502 (2012).
Yang, Y. & Kumar, K. S. Elastic strain effects on the catalytic response of Pt and Pd thin films deposited on Pd–Zr metallic glass. J. Mater. Res. 32, 2690–2699 (2017).
Wagner, S. & Pundt, A. Quasi-thermodynamic model on hydride formation in palladium–hydrogen thin films: impact of elastic and microstructural constraints. Int. J. Hydrog. Energy 41, 2727–2738 (2016).
Baldi, A., Narayan, T. C., Koh, A. L. & Dionne, J. A. In situ detection of hydrogen-induced phase transitions in individual palladium nanocrystals. Nat. Mater. 13, 1143–1148 (2014).
Ulvestad, A. et al. Avalanching strain dynamics during the hydriding phase transformation in individual palladium nanoparticles. Nat. Commun. 6, 10092 (2015).
Akiba, H. et al. Nanometer-size effect on hydrogen sites in palladium lattice. J. Am. Chem. Soc. 138, 10238–10243 (2016).
Li, G. et al. In situ modification of a delafossite-type PdCoO2 bulk single crystal for reversible hydrogen sorption and fast hydrogen evolution. ACS Energy Lett. 4, 2185–2191 (2019).
Kikugawa, N. et al. Interplanar coupling-dependent magnetoresistivity in high-purity layered metals. Nat. Commun. 7, 10903 (2016).
Takatsu, H. et al. Roles of high-frequency optical phonons in the physical properties of the conductive delafossite PdCoO2. J. Phys. Soc. Jpn 76, 104701 (2007).
Moulder, J. F., Stickle, W. F., Sobol, P. E. & Bomen, K. D. Handbook of X-ray Photoelectron Spectroscopy (Perkin-Elmer Corporation, 1992).
Acknowledgements
We gratefully acknowledge P. Schützendübe and M. Wieland for the XPS measurements, and E. Frau and P. Iyengar for the introduction to and assistance with the SECM measurements. Y. Eren Suyolcu, A. Bandarenka, N. Vargas-Barbosa, and especially R. Merkle are acknowledged for fruitful discussions. We further acknowledge C. Hohmann (NIM) for creating the figure in the table of contents. E.A.-L. acknowledges support from the SNF Ambizione Energy programme and the research programme of FOM, which is financially supported by the Netherlands Organisation for Scientific Research (NWO). S.Z. and C.S. acknowledge financial support from the German Research Foundation (DFG) under the priority programme SPP 1613 (DFG SCHE 634/12-2). B.V.L. acknowledges the Cluster of Excellence e-conversion. F.P., E.A.-L., B.V.L. and A.F.i.M. thank the MPS-EPFL Center for financial and logistic support.
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F.P., D.W., F.H. and B.V.L. conceived the project and the contributing measurements. The materials were synthesized by D.W., L.D. and R.E. All sample preparation and electrochemical measurements were done by F.P. The SECM data were analysed and discussed by E.A.-L. and F.P. G.R. and F.P. analysed the XPS data. S.Z. performed the STEM experiments, including the data analysis and presentation. F.P. created all of the other graphs. F.P. and B.V.L. wrote the manuscript. All authors, including V.D., C.S. and A.F.iM. contributed to discussion of the measurements, data interpretation and manuscript preparation.
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Podjaski, F., Weber, D., Zhang, S. et al. Rational strain engineering in delafossite oxides for highly efficient hydrogen evolution catalysis in acidic media. Nat Catal 3, 55–63 (2020). https://doi.org/10.1038/s41929-019-0400-x
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DOI: https://doi.org/10.1038/s41929-019-0400-x
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