Atomically dispersed Lewis acid sites boost 2-electron oxygen reduction activity of carbon-based catalysts

Abstract

Elucidating the structure-property relationship is crucial for the design of advanced electrocatalysts towards the production of hydrogen peroxide (H ₂O ₂). In this work, we theoretically and experimentally discovered that atomically dispersed Lewis acid sites (octahedral M–O species, M = aluminum (Al), gallium (Ga)) regulate the electronic structure of adjacent carbon catalyst sites. Density functional theory calculation predicts that the octahedral M–O with strong Lewis acidity regulates the electronic distribution of the adjacent carbon site and thus optimizes the adsorption and desorption strength of reaction intermediate (*OOH). Experimentally, the optimal catalyst (oxygen-rich carbon with atomically dispersed Al, denoted as O-C(Al)) with the strongest Lewis acidity exhibited excellent onset potential (0.822 and 0.526 V versus reversible hydrogen electrode at 0.1 mA cm ⁻² H ₂O ₂ current in alkaline and neutral media, respectively) and high H ₂O ₂ selectivity over a wide voltage range. This study provides a highly efficient and low-cost electrocatalyst for electrochemical H ₂O ₂ production.

Abstract

H ₂O ₂ production via oxygen reduction offers a renewable approach to obtain an often-used oxidant. Here, authors show the incorporation of Lewis acid sites into carbon-based materials to improve H ₂O ₂ electrosynthesis.