Dynamic electrocatalysis: Examining resonant catalytic rate enhancement under oscillating electrochemical potential

A microkinetic analysis is presented for a generalized electrocatalytic reaction mechanism to evaluate whether oscillating electrochemical potential can be used to achieve resonant catalytic rate enhancement. It is illustrated that because changing the potential changes the free energy of reaction, this approach is conceptually distinct from oscillating binding energies of catalytic intermediates as within catalytic resonance theory. For faradaic reactions in series, no enhancements relative to the maximum steady-state turnover rate (within the potential range spanned by oscillation) are achievable, even in cases where the potential limits favor adsorption and desorption, respectively. It is possible to exceed a time-averaged steady-state rate ( weighted by time at each condition), although only if the elementary reactions show disparate responses to potential. In contrast, if a faradaically driven parallel reaction controls surface coverage of a strongly adsorbed blocking species, significant dynamic enhancements over the maximum steady-state can be achieved, albeit at a cost of thermodynamic efficiency.