Understanding the
influence of potential on electrochemical surface
reaction kinetics remains a challenge in identifying catalytic materials
for numerous important reactions including water splitting (OER),
hydrogen evolution (HER), and CO2 reduction, among others.
Limitations in computational methods, complicated by the unique environment
of the electrode–electrolyte interface, have compelled many
studies to focus on the thermodynamics of reaction schemes and to
generalize inferences about the kinetics of charge transfer. In instances
where activation barrier estimates are available, they are typically
assumed to follow the empirical Butler–Volmer (BV) model. In
this Perspective, we illustrate that the relative magnitudes and potential-dependences
of elementary barriers can have a marked effect on the properties
of a catalyst deemed “optimal” for a given reaction.
We use a simple pseudosteady-state analysis of two sequential surface-mediated
charge transfers to assess the degree of rate control of each step
as a function of the material and conditions. We compare BV kinetics
to Marcus theory and also discuss more recent models that are specific
to the interactions of an adsorbate with the electronic structure
of a surface. Recent developments in the full simulation of charge
transfer to surface species are also briefly discussed. Finally, we
highlight the need for assessment of kinetics and identification of
activity descriptors that are optimal at relevant operating
conditions, and we conclude with an outlook on current research
needs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.