A comprehensive comparison of oxygen and nitrogen functionalities in carbon and their implications for the oxygen reduction reaction

Carbon materials have widespread use in catalysis mainly due to their abundance, high conductivity, large surface area, and facile functionalization through heteroatom-doping. However, both, the stability against corrosion and the catalytic performance caused by the exposure to high potentials present in rel-evant electrocatalytic reactions such as the oxygen reduction reaction (ORR) is recurrently underesti-mated. We demonstrate that importance of oxygen and nitrogen binding motives to tailor the oxygen reduction activity, selectivity and stability against corrosion. Spectroscopic results revealed that the exposure to high oxidative potentials causes i) oxidation of N-groups and decrease in N content; and ii) enrichment of CAO (hydroxyl and ethers), C@O (quinones), and COOH functional groups and, together, dramatically impact the ORR activity and selectivity. We present guidelines how the activity, selectivity and stability can be precisely tuned. The developed guidelines highlight the potential of tailoring the oxy-gen and nitrogen containing functional groups on carbon catalysts for future catalytic applications.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Carbon materials are widely used in catalysis due to their abundance, conductivity, large surface area, and ease of functionalization. However, the importance of oxygen and nitrogen binding motives in tailoring the oxygen reduction activity, selectivity, and stability against corrosion is often underestimated. Guidelines have been developed to precisely tune the activity, selectivity, and stability by adjusting the functional groups containing oxygen and nitrogen on carbon catalysts.