Understanding the effects of electrolyte cations on the electrochemical reduction CO2
Ringe, S., Clark, E., Resasco, J., Walton, A., Seger, B., Bell, A., Chan, K. Understanding cation effects in electrochemical CO2 reduction. Energy Environ. Sci., DOI: 10.1039/C9EE01341E (2019).
The effects of electrolyte cation size on the electrochemical reduction of CO2 over Ag and Cu are explained theoretically.
Significance and Impact
The selectivity of Ag for CO formation and Cu for C2 product formation is due to stabilization of dipolar intermediates by the double-layer field in created by hydrated cations – the smaller the hydrated cation size, the stronger the field.
The ion-size modified, Poisson-Boltzmann equation is solved to determine the charge on the metal surface and hence the double-layer field.
The double-layer field is used in DFT calculations of the stability of intermediates involved in CO formation on Ag and C2 product formation on Cu