Mixed‐Potential‐Driven Catalysis in Glucose Oxidation

Abstract

Mixed‐potential‐driven catalysis, in which anodic and cathodic reactions are electrochemically short‐circuited, converts the Gibbs free energy difference into overpotentials that drive both half‐reactions without an external energy input. We developed a theoretical framework that suggests that the catalytic activities of individual catalyst components determine the distribution of the aforementioned driving forces. By short‐circuiting spatially separated electrodes made of Au/C with reduced‐graphene oxide, nitrogen‐doped reduced‐graphene oxide, caged nitrogen‐doped reduced‐graphene oxide, Pt/C, or Pd/C, we demonstrated this framework using glucose oxidation as a model, given its significance in generating high‐value products and its potential in fuel cell technology. A short‐circuit current was detected in the absence of external potentials, demonstrating electron transfer during glucose oxidation. Additionally, by correlating the mixed potential predicted from the polarization curves of each half‐reaction with the mixed potential measured in short‐circuit experiments under the same conditions, we confirmed that the kinetic activity of each catalyst component determines the mixed potential. This, in turn, affects the division of the driving force. Driving force partitioning is a potent tool for enhancing the overall rate of a reaction. Our findings may facilitate the design of not only glucose oxidation catalysts but also other heterogeneous catalysts based on mixed‐potential‐driven reaction mechanisms.