The Still Elusive Role of Lightweight Doping in Carbon‐Based Electrocatalysts for the Selective Oxygen Reduction Reaction to Hydrogen Peroxide

Abstract

AbstractThe two‐electron electrocatalytic oxygen reduction reaction (ORR) to hydrogen peroxide (H2O2) is a valuable alternative to the more conventional and energy‐intensive anthraquinone process. From a circularity viewpoint, metal‐free catalysts constitute a sustainable alternative for the process. In particular, lightweight hetero‐doped C‐materials are cost‐effective and easily scalable samples that replace ‐ more and more frequently – the use of critical raw elements in the preparation of highly performing (electro)catalysts. Anyhow, their large‐scale exploitation in industrial processes still suffers from technical limits of samples upscale and reproducibility other than a still moderate comprehension of their action mechanism in the process. This concept article offers a comprehensive and exhaustive “journey” through the most representative lightweight hetero‐doped C‐based electrocatalysts and their performance in the 2e− ORR process. It provides an interpretation of phenomena at the triple‐phase interface of solid catalyst, liquid electrolyte and gaseous oxygen based on the doping‐driven generation of ideal electronic microenvironments at the catalyst surface.