Carbon corrosion mechanism on nitrogen-doped carbon support — A density functional theory study. (6th April 2021)

• Record Type: Journal Article
• Authors: Li, Yunqi; Li, Jing; Wang, Yang-Gang; Chen, Xiran; Liu, Mingtao; Zheng, Zhong; Peng, Xihong
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 24(2021)
• Page Start: 13273
• Page End: 13282
• Publication Date: 2021-04-06
• Subjects: Carbon corrosion mechanism -- Nitrogen-doped carbon -- Proton exchange membrane fuel cell -- Degradation -- Density functional theory; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.01.148
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this work, density functional theory (DFT) calculations were used to investigate the mechanism of carbon corrosion on nitrogen-doped carbon support. Free energy diagrams were generated based on three proposed reaction pathways to evaluate corrosion mechanisms. The most energetically preferred mechanism on nitrogen-doped carbon was determined. The results show that the step of water dissociation to form # OH was the rate-determining step for gra-G-1N (graphene doped with graphitic N) and pyrr-G-1N (graphene doped with pyrrolic N). As for graphene doped with pyridinic N, the step of C # OC # O formation was critical. It was found that the control of nitrogen concentration was necessary for precisely designing optimized carbon materials. Abundance of nitrogen moieties aggravated the carbon corrosion. When the high potential was applied, specific types of graphitic N and pyridinic N were found to be favorable carbon modifications to improve carbon corrosion resistance. Moreover, the solvent effect was also investigated. The results provide theoretical insights and design guidelines to improve corrosion resistance in carbon support through material modification by inhibiting the adsorption of surface oxides (OH, O, and OOH). Graphical abstract: Image 1