A comparative study of CO oxidation on Cu-doped C3N monolayer with N and C vacancies

Abstract

In this study, we employ density functional theory based on first-principles calculations to investigate the CO oxidation performance of a Cu-doped C3N monolayer with N and C vacancies, which is a promising low-temperature and high-activity catalyst. We find that Cu dopants are more stably anchored at both the N and C vacancies of the C3N monolayer. To comprehensively understand the effect of N and C vacancies on CO oxidation, we investigate both the Eley–Rideal and Langmuir–Hinshelwood (LH) mechanisms. Our results indicate that the LH mechanism exhibits much lower barriers for the rate-limiting step of CO oxidation, suggesting its excellent performance in this process. Moreover, the charge state of Cu atoms and the asymmetric atomic interface at the C vacancy lead to a lower rate-limiting barrier for CO oxidation compared to that at the N vacancy (0.5 vs 0.71 eV). This study represents a promising strategy to enhance the activity and selectivity of CO oxidation by controlling the asymmetric atomic interface of single-atom catalysts.