Understanding the chemical environment of bioelectrocatalysis

Abstract

Bioelectrochemistry utilizes a variety high-surface-area macroporous and mesoporous electrode architectures to increase the protein loading and the electrochemical response. Although the local chemical environment was studied in heterogenous and small-molecule electrocatalysis, enzyme electrochemistry conditions are still largely established using bulk solution assays. This is despite the fact that it does not take into account the nonequilibrium conditions within the confined electrode space. We use electrochemical and computational methods to study the local environment for fuel-producing oxygenoreductases within porous electrode structures. This improved understanding of local conditions allowed for simple manipulation of electrolyte solutions by adjusting bulk pH and buffer K_{You can find more information at}To achieve the optimal pH local to maximize enzyme activity When the electrolyte is applied to macroporous inverted opal electrodes the benefits of higher loading were utilized. The electrolyte was then adjusted to reach 8.0mA cm²H₂Evolution reaction and 3.6mA cm²CO₂Reduced reaction (CO).₂RR) demonstrating an 18-fold improvement over previously reported enzymatic COP₂RR systems. This research highlights how important it is to understand the confined enzymatic environment. It will expand the capabilities of enzyme-bioelectrocatalysis. These considerations and insights can be directly applied to both bio(photo)electrochemical fuel and chemical synthesis, as well as enzymatic fuel cells, to significantly improve the fundamental understanding of the enzymeelectrode interface as well as device performance.