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Correlating hydration free energy and specific adsorption of alkali metal cations during CO2 electroreduction on Au

Abstract

Specifically adsorbed alkali metal cations on metal electrodes have been hypothesized to influence the reduction of CO2. However, experimental detection of these cations during CO2 reduction remains elusive. Herein, employing the asymmetric CH3 deformation band of tetramethylammonium as a vibrational probe of the aqueous electrolyte–polycrystalline Au interface, we monitored the displacement of specifically adsorbed tetramethylammonium by alkali metal cations. We found that the coverage of specifically adsorbed alkali metal cations during CO2-to-CO reduction follows the order Li+ < Na+ < K+ < Cs+ for the same bulk concentration. The alkali metal cations’ experimentally observed surface coverages correlate with their free energies of hydration. Furthermore, the rate of CO2-to-CO conversion increases with the coverage of specifically adsorbed alkali metal cations. Our observations suggest that the degree to which alkali metal cations undergo partial dehydration at the electrode–electrolyte interface plays a key role in their ability to promote CO2-to-CO reduction.

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Fig. 1: Response of the CH3 deformation band of methyl4N+ to changes in EDL structure.
Fig. 2: Comparison of CH3 deformation bands of methyl4N+ in different electrolytes.
Fig. 3: Dependence of CH3 deformation band on charge on the molecule.
Fig. 4: Response of CH3 deformation band to addition of K+ to the electrolyte.
Fig. 5: Change in area of 1,482 cm−1 band with bulk alkali metal cation concentration.
Fig. 6: Correlation between area of 1,482 cm−1 band and alkali cation hydration free energy.
Fig. 7: Dependence of electrocatalysis on area of 1,482 cm−1 integrated band.

Data availability

Representative data and extended datasets that support the findings reported in this study are available in the manuscript and the Supplementary Information. The data in the figures shown in the main text and DFT-calculated coordinates for the optimized geometries of the cations on Au(111) are provided in machine-readable formats as supplementary files. Additional data are available from the corresponding authors upon reasonable request.

References

  1. Parsons, R. The electrical double layer: recent experimental and theoretical developments. Chem. Rev. 90, 813–826 (1990).

    CAS  Article  Google Scholar 

  2. Dunwell, M., Yan, Y. & Xu, B. Understanding the influence of the electrochemical double-layer on heterogeneous electrochemical reactions. Curr. Opin. Chem. Eng. 20, 151–158 (2018).

    Article  Google Scholar 

  3. Magnussen, O. M. & Groß, A. Toward an atomic-scale understanding of electrochemical interface structure and dynamics. J. Am. Chem. Soc. 141, 4777–4790 (2019).

    CAS  PubMed  Article  Google Scholar 

  4. Waegele, M. M., Gunathunge, C. M., Li, J. & Li, X. How cations affect the electric double layer and the rates and selectivity of electrocatalytic processes. J. Chem. Phys. 151, 160902 (2019).

    PubMed  Article  CAS  Google Scholar 

  5. Grahame, D. C. The electrical double layer and the theory of electrocapillarity. Chem. Rev. 41, 441–501 (1947).

    CAS  PubMed  Article  Google Scholar 

  6. Sorenson, S. A., Patrow, J. G. & Dawlaty, J. M. Solvation reaction field at the interface measured by vibrational sum frequency generation spectroscopy. J. Am. Chem. Soc. 139, 2369–2378 (2017).

    CAS  PubMed  Article  Google Scholar 

  7. Raberg, J. H. et al. Probing electric double-layer composition via in situ vibrational spectroscopy and molecular simulations. J. Phys. Chem. Lett. 10, 3381–3389 (2019).

    CAS  PubMed  Article  Google Scholar 

  8. Zhang, R. et al. Potential-dependent layering in the electrochemical double layer of water-in-salt electrolytes. ACS Appl. Energy Mater. 3, 8086–8094 (2020).

    CAS  Article  Google Scholar 

  9. Xue, S., Garlyyev, B., Auer, A., Kunze-Liebhäuser, J. & Bandarenka, A. S. How the nature of the alkali metal cations influences the double-layer capacitance of Cu, Au, and Pt single-crystal electrodes. J. Phys. Chem. C 124, 12442–12447 (2020).

    CAS  Article  Google Scholar 

  10. Zhang, Y. et al. Real-time characterization of the fine structure and dynamics of an electrical double layer at electrode–electrolyte interfaces. J. Phys. Chem. Lett. 12, 5279–5285 (2021).

    CAS  PubMed  Article  Google Scholar 

  11. Goldsmith, Z. K., Calegari Andrade, M. F. & Selloni, A. Effects of applied voltage on water at a gold electrode interface from ab initio molecular dynamics. Chem. Sci. 12, 5865–5873 (2021).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  12. Ojha, K., Doblhoff-Dier, K. & Koper, M. T. M. Double-layer structure of the Pt(111)–aqueous electrolyte interface. Proc. Natl Acad. Sci. USA 119, e2116016119 (2022).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  13. Herasymenko, P. & Šlendyk, I. Wasserstoffüberspannung und adsorption der ionen [hydrogen overpotential and adsorption of ions.]. Z. Phys. Chem. (N F) 149, 123–139 (1930).

    CAS  Google Scholar 

  14. Frumkin, A. N. Influence of cation adsorption on the kinetics of electrode processes. Trans. Faraday Soc. 55, 156–167 (1959).

    CAS  Article  Google Scholar 

  15. Danilovic, N. et al. The effect of noncovalent interactions on the HOR, ORR, and HER on Ru, Ir, and Ru0.50Ir0.50 metal surfaces in alkaline environments. Electrocatalysis 3, 221–229 (2012).

    CAS  Article  Google Scholar 

  16. Arán-Ais, R. M., Gao, D. & Roldan Cuenya, B. Structure- and electrolyte-sensitivity in CO2 electroreduction. Acc. Chem. Res. 51, 2906–2917 (2018).

    PubMed  Article  CAS  Google Scholar 

  17. Li, J. et al. Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper. Nat. Commun. 12, 3264 (2021).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  18. Rosca, V., Duca, M., de Groot, M. T. & Koper, M. T. M. Nitrogen cycle electrocatalysis. Chem. Rev. 109, 2209–2244 (2009).

    CAS  PubMed  Article  Google Scholar 

  19. McEnaney, J. M. et al. Electrolyte engineering for efficient electrochemical nitrate reduction to ammonia on a titanium electrode. ACS Sustain. Chem. Eng. 8, 2672–2681 (2020).

    CAS  Article  Google Scholar 

  20. Yang, X., Wang, Y., Li, C. M. & Wang, D. Mechanisms of water oxidation on heterogeneous catalyst surfaces. Nano Res. 14, 3446–3457 (2021).

    CAS  Article  Google Scholar 

  21. Huang, J., Li, M., Eslamibidgoli, M. J., Eikerling, M. & Groß, A. Cation overcrowding effect on the oxygen evolution reaction. JACS Au 1, 1752–1765 (2021).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  22. Resasco, J. et al. Promoter effects of alkali metal cations on the electrochemical reduction of carbon dioxide. J. Am. Chem. Soc. 139, 11277–11287 (2017).

    CAS  PubMed  Article  Google Scholar 

  23. Rao, R. R. et al. pH- and cation-dependent water oxidation on rutile RuO2(110). J. Phys. Chem. C 125, 8195–8207 (2021).

    CAS  Article  Google Scholar 

  24. Strmcnik, D. et al. The role of non-covalent interactions in electrocatalytic fuel-cell reactions on platinum. Nat. Chem. 1, 466–472 (2009).

    CAS  PubMed  Article  Google Scholar 

  25. Feaster, J. T. et al. Understanding the influence of [EMIM]Cl on the suppression of the hydrogen evolution reaction on transition metal electrodes. Langmuir 33, 9464–9471 (2017).

    CAS  PubMed  Article  Google Scholar 

  26. Bhargava, S. S. et al. Exploring multivalent cations-based electrolytes for CO2 electroreduction. Electrochim. Acta 394, 139055 (2021).

    CAS  Article  Google Scholar 

  27. Chen, L. D., Urushihara, M., Chan, K. & Nørskov, J. K. Electric field effects in electrochemical CO2 reduction. ACS Catal. 6, 7133–7139 (2016).

    CAS  Article  Google Scholar 

  28. Akhade, S. A., McCrum, I. T. & Janik, M. J. The impact of specifically adsorbed ions on the copper-catalyzed electroreduction of CO2. J. Electrochem. Soc. 163, 477–484 (2016).

    Article  CAS  Google Scholar 

  29. Gunathunge, C. M., Ovalle, V. J. & Waegele, M. M. Probing promoting effects of alkali cations on the reduction of CO at the aqueous electrolyte/copper interface. Phys. Chem. Chem. Phys. 19, 30166–30172 (2017).

    CAS  PubMed  Article  Google Scholar 

  30. Chen, X., McCrum, I. T., Schwarz, K. A., Janik, M. J. & Koper, M. T. M. Co-adsorption of cations as the cause of the apparent pH dependence of hydrogen adsorption on a stepped platinum single-crystal electrode. Angew. Chem. Int. Ed. 56, 15025–15029 (2017).

    CAS  Article  Google Scholar 

  31. Pérez-Gallent, E., Marcandalli, G., Figueiredo, M. C., Calle-Vallejo, F. & Koper, M. T. M. Structure- and potential-dependent cation effects on CO reduction at copper single-crystal electrodes. J. Am. Chem. Soc. 139, 16412–16419 (2017).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  32. Monteiro, M. C. O. et al. Absence of CO2 electroreduction on copper, gold and silver electrodes without metal cations in solution. Nat. Catal. 4, 654–662 (2021).

    CAS  Article  Google Scholar 

  33. Zhu, Q., Wallentine, S. K., Deng, G.-H., Rebstock, J. A. & Baker, L. R. The solvation-induced Onsager reaction field rather than the double-layer field controls CO2 reduction on gold. JACS Au 2, 472–482 (2022).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  34. Liu, H., Liu, J. & Yang, B. Promotional role of a cation intermediate complex in C2 formation from electrochemical reduction of CO2 over cu. ACS Catal. 11, 12336–12343 (2021).

    CAS  Article  Google Scholar 

  35. Fink, A. G. et al. Impact of alkali cation identity on the conversion of \({\mathrm{HCO}}_{3}^{-}\) to CO in bicarbonate electrolyzers. ChemElectroChem 8, 2094–2100 (2021)..

  36. Singh, M. R., Kwon, Y., Lum, Y., Ager, J. W. & Bell, A. T. Hydrolysis of electrolyte cations enhances the electrochemical reduction of CO2 over Ag and Cu. J. Am. Chem. Soc. 138, 13006–13012 (2016).

    CAS  PubMed  Article  Google Scholar 

  37. Ayemoba, O. & Cuesta, A. Spectroscopic evidence of size-dependent buffering of interfacial pH by cation hydrolysis during CO2 electroreduction. ACS Appl. Mater. Interfaces 9, 27377–27382 (2017).

    CAS  PubMed  Article  Google Scholar 

  38. Zhang, F. & Co, A. C. Direct evidence of local pH change and the role of alkali cation during CO2 electroreduction in aqueous media. Angew. Chem. Int. Ed. 58, 2–10 (2019).

    Article  CAS  Google Scholar 

  39. Li, J., Li, X., Gunathunge, C. M. & Waegele, M. M. Hydrogen bonding steers the product selectivity of electrocatalytic CO reduction. Proc. Natl Acad. Sci. USA 116, 9220–9229 (2019).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  40. Zhang, Z.-Q., Banerjee, S., Thoi, V. S. & Shoji Hall, A. Reorganization of interfacial water by an amphiphilic cationic surfactant promotes CO2 reduction. J. Phys. Chem. Lett. 11, 5457–5463 (2020).

    CAS  PubMed  Article  Google Scholar 

  41. Hussain, G. et al. How cations determine the interfacial potential profile: relevance for the CO2 reduction reaction. Electrochim. Acta 327, 135055 (2019).

    CAS  Article  Google Scholar 

  42. Malkani, A. S. et al. Understanding the electric and nonelectric field components of the cation effect on the electrochemical CO reduction reaction. Sci. Adv. 6, eabd2569 (2020).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  43. Wallentine, S., Bandaranayake, S., Biswas, S. & Baker, L. R. Direct observation of carbon dioxide electroreduction on gold: site blocking by the stern layer controls CO2 adsorption kinetics. J. Phys. Chem. Lett. 11, 8307–8313 (2020).

    CAS  PubMed  Article  Google Scholar 

  44. Mills, J. N., McCrum, I. T. & Janik, M. J. Alkali cation specific adsorption onto fcc(111) transition metal electrodes. Phys. Chem. Chem. Phys. 16, 13699–13707 (2014).

    CAS  PubMed  Article  Google Scholar 

  45. Matanovic, I., Atanassov, P., Garzon, F. & Henson, N. J. Density functional theory study of the alkali metal cation adsorption on Pt(111), Pt(100), and Pt(110) surfaces. ECS Trans. 61, 47–53 (2014).

    CAS  Article  Google Scholar 

  46. McCrum, I. T. & Janik, M. J. pH and alkali cation effects on the Pt cyclic voltammogram explained using density functional theory. J. Phys. Chem. C. 120, 457–471 (2016).

    CAS  Article  Google Scholar 

  47. Frank, D. G. et al. pH and potential dependence of the electrical double layer at well-defined electrode surfaces: Cs+ and Ca2+ ions at Pt(111) (\(2\sqrt{3}\times 2\sqrt{3}\))R30°-CN, Pt(111) (\(2\sqrt{3}\times 2\sqrt{3}\))R14°-CN, and Pt(111) (2 × 2)-SCN. Langmuir 1, 587–592 (1985).

  48. Salaita, G. N. et al. Structure and composition of a platinum(111) surface as a function of pH and electrode potential in aqueous bromide solutions. Langmuir 2, 828–835 (1986).

    CAS  Article  Google Scholar 

  49. Lucas, C. A., Thompson, P., Gründer, Y. & Markovic, N. M. The structure of the electrochemical double layer: Ag(111) in alkaline electrolyte. Electrochem. Commun. 13, 1205–1208 (2011).

    CAS  Article  Google Scholar 

  50. Strmcnik, D. et al. Effects of Li+, K+, and Ba2+ cations on the ORR at model and high surface area Pt and Au surfaces in alkaline solutions. J. Phys. Chem. Lett. 2, 2733–2736 (2011).

    CAS  Article  Google Scholar 

  51. Liu, Y., Kawaguchi, T., Pierce, M. S., Komanicky, V. & You, H. Layering and ordering in electrochemical double layers. J. Phys. Chem. Lett. 9, 1265–1271 (2018).

    CAS  PubMed  Article  Google Scholar 

  52. Kawaguchi, T., Liu, Y., Karapetrova, E. A., Komanicky, V. & You, H. In-situ to ex-situ in-plane structure evolution of stern layers on Pt(111) surface: surface X-ray scattering studies. J. Electroanal. Chem. 875, 114495 (2020).

    CAS  Article  Google Scholar 

  53. Sarkar, S., Maitra, A., Banerjee, S., Thoi, V. S. & Dawlaty, J. M. Electric fields at metal–surfactant interfaces: a combined vibrational spectroscopy and capacitance study. J. Phys. Chem. B 124, 1311–1321 (2020).

    CAS  PubMed  Article  Google Scholar 

  54. Pennathur, A. K., Voegtle, M. J., Menachekanian, S. & Dawlaty, J. M. Strong propensity of ionic liquids in their aqueous solutions for an organic-modified metal surface. J. Phys. Chem. C 124, 7500–7507 (2020).

    CAS  Article  Google Scholar 

  55. Voegtle, M. J. et al. Interfacial polarization and ionic structure at the ionic liquid–metal interface studied by vibrational spectroscopy and molecular dynamics simulations. J. Phys. Chem. C 125, 2741–2753 (2021).

    CAS  Article  Google Scholar 

  56. Harmon, K. M., Gennick, I. & Madeira, S. L. Hydrogen bonding. iv. Correlation of infrared spectral properties with C–H  X hydrogen bonding and crystal habit in tetramethylammonium ion salts. J. Phys. Chem. 78, 2585–2591 (1974).

    CAS  Article  Google Scholar 

  57. McCrum, I. T., Hickner, M. A. & Janik, M. J. Quaternary ammonium cation specific adsorption on platinum electrodes: a combined experimental and density functional theory study. J. Electrochem. Soc. 165, 114–121 (2018).

    Article  CAS  Google Scholar 

  58. He, F. et al. Stability of quaternary akyl ammonium cations during the hydrogen evolution reduction: a differential electrochemical mass spectrometry study. J. Phys. Chem. C 125, 5715–5722 (2021).

    CAS  Article  Google Scholar 

  59. Deng, Z. & Irish, D. E. Potential dependence of the orientation of (CH3)4N+ adsorbed on a silver electrode. a SERS investigation. J. Phys. Chem. 98, 9371–9373 (1994).

    CAS  Article  Google Scholar 

  60. Trasatti, S. & Lust, E. In Modern Aspects of Electrochemistry (eds White, R. E. et al.) 1–215 (Springer, 1999).

  61. Osawa, M. Dynamic processes in electrochemical reactions studied by surface-enhanced infrared absorption spectroscopy (SEIRAS). Bull. Chem. Soc. Jpn 70, 2861–2880 (1997).

    CAS  Article  Google Scholar 

  62. Wuttig, A., Yaguchi, M., Motobayashi, K., Osawa, M. & Surendranath, Y. Inhibited proton transfer enhances Au-catalyzed CO2-to-fuels selectivity. Proc. Natl Acad. Sci. USA 113, 4585–4593 (2016).

    Article  CAS  Google Scholar 

  63. Dong, Q., Zhang, X., He, D., Lang, C. & Wang, D. Role of H2O in CO2 electrochemical reduction as studied in a water-in-salt system. ACS Cent. Sci. 5, 1461–1467 (2019).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  64. Zhang, B. A., Ozel, T., Elias, J. S., Costentin, C. & Nocera, D. G. Interplay of homogeneous reactions, mass transport, and kinetics in determining selectivity of the reduction of CO2 on gold electrodes. ACS Cent. Sci. 5, 1097–1105 (2019).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  65. Ringe, S. et al. Double layer charging driven carbon dioxide adsorption limits the rate of electrochemical carbon dioxide reduction on gold. Nat. Commun. 11, 33 (2020).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  66. Gambarotta, S., Arena, F., Floriani, C. & Zanazzi, P. F. Carbon dioxide fixation: bifunctional complexes containing acidic and basic sites working as reversible carriers. J. Am. Chem. Soc. 104, 5082–5092 (1982).

    CAS  Article  Google Scholar 

  67. Benn, E. E., Gaskey, B. & Erlebacher, J. D. Suppression of hydrogen evolution by oxygen reduction in nanoporous electrocatalysts. J. Am. Chem. Soc. 139, 3663–3668 (2017).

    PubMed  Article  CAS  Google Scholar 

  68. Chen, W., Liao, L. W., Cai, J., Chen, Y.-X. & Stimming, U. Unraveling complex electrode processes by differential electrochemical mass spectrometry and the rotating ring-disk electrode technique. J. Phys. Chem. C 123, 29630–29637 (2019).

    CAS  Article  Google Scholar 

  69. Bondue, C. J., Graf, M., Goyal, A. & Koper, M. T. M. Suppression of hydrogen evolution in acidic electrolytes by electrochemical CO2 reduction. J. Am. Chem. Soc. 143, 279–285 (2021).

    CAS  PubMed  Article  Google Scholar 

  70. Wuttig, A. & Surendranath, Y. Impurity ion complexation enhances carbon dioxide reduction catalysis. ACS Catal. 5, 4479–4484 (2015).

    CAS  Article  Google Scholar 

  71. Shang, H. et al. Effect of surface ligands on gold nanocatalysts for CO2 reduction. Chem. Sci. 11, 12298–12306 (2020).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  72. Mezzavilla, S., Horch, S., Stephens, I. E. L., Seger, B. & Chorkendorff, I. Structure sensitivity in the electrocatalytic reduction of CO2 with gold catalysts. Angew. Chem. Int. Ed. 58, 3774–3778 (2019).

    CAS  Article  Google Scholar 

  73. Gunathunge, C. M., Li, J., Li, X. & Waegele, M. M. Surface-adsorbed CO as an infrared probe of electrocatalytic interfaces. ACS Catal. 10, 11700–11711 (2020).

    CAS  Article  Google Scholar 

  74. Gunathunge, C. M., Li, J., Li, X., Hong, J. J. & Waegele, M. M. Revealing the predominant surface facets of rough Cu electrodes under electrochemical conditions. ACS Catal. 10, 6908–6923 (2020).

    CAS  Article  Google Scholar 

  75. Dunwell, M., Yang, X., Yan, Y. & Xu, B. Potential routes and mitigation strategies for contamination in interfacial specific infrared spectroelectrochemical studies. J. Phys. Chem. C 122, 24658–24664 (2018).

    CAS  Article  Google Scholar 

  76. Cave, E. R. et al. Electrochemical CO2 reduction on au surfaces: mechanistic aspects regarding the formation of major and minor products. Phys. Chem. Chem. Phys. 19, 15856–15863 (2017).

    CAS  PubMed  Article  Google Scholar 

  77. Marcus, Y. Ion Properties (Marcel Dekker, 1997).

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Acknowledgements

This work was supported by a CAREER award (to M.M.W.) from the National Science Foundation (no. CHE-1847841). N.A. and M.J.J. acknowledge the National Science Foundation for support (award no. CHE-1665155).

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All authors discussed the results and commented on and revised the manuscript. M.M.W. and V.J.O. conceived and designed the experiments. V.J.O. conducted the experiments. Y.-S.H. participated in data collection. M.J.J. and N.A. contributed the DFT work.

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Correspondence to Michael J. Janik or Matthias M. Waegele.

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Nature Catalysis thanks Yanwei Lum, Wenbin Cai and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Figs. 1–11, Tables 1–4 and Notes 1 and 2.

Supplementary Data 1

Coordinates for optimized geometries of cations on Au(111).

Supplementary Data 2

Machine-readable data shown in Figs. 1–7.

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Ovalle, V.J., Hsu, YS., Agrawal, N. et al. Correlating hydration free energy and specific adsorption of alkali metal cations during CO2 electroreduction on Au. Nat Catal 5, 624–632 (2022). https://doi.org/10.1038/s41929-022-00816-0

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