Interfacial pH measurements during CO 2 reduction on gold using a rotating ring-disk electrode

Physical Chemistry Chemical Physics, vol. 25, pp. 2897–2906

Abstract

RHE, which indicates a change of the dominant buffering species. Through scan rate-dependent voltammetry and chronopotentiometry experiments, the homogenous reactions are shown to reach equilibrium within the time scale of the pH measurements, so that the interfacial concentrations of different carbonaceous species can be calculated using equilibrium constants. Furthermore, pH measurements were also performed under different conditions to disentangle the relationship between the interfacial pH and other electrolyte effects. The buffer effect of alkali metal cations is confirmed, showing that weakly hydrated cations lead to less pronounced pH gradients. Finally, we probe to which extent increasing mass transport and the electrolyte buffer capacity can aid in suppressing the increase of the interfacial pH, showing that the buffer capacity is the dominant factor in suppressing interfacial pH variations.

Authors 2

1. Mariana C. O. Monteiro Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands

2. Marc T. M. Koper corresponding Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands