On the Pathways of N-Doped Carbon Materials Active Sites During Oxygen Reduction Reaction

Abstract

N-doped carbon materials have been considered as one of the most promising options for the replacement of platinum-based electrocatalysts towards the oxygen reduction reaction. However, what is known about this kind of catalysts and the identification of the active sites is still contradictory. Most of the scientific literature focuses on experimental characterization before ORR testing, leading to a consistent lack of knowledge about the surface chemistry at operando conditions. The development of operando techniques is, up to now, not enough to unravel with accuracy the reasons why these catalysts are as active as platinum-based electrodes and to understand the deactivation with time of use. In this work, the changes occurring in the active sites of N-doped carbon catalysts have been analysed in detail through pre- and post-ORR extended characterization of selectively N-doped carbon materials, along with sophisticated computational modelling.