N-coordinated Dual-metal Single Site Catalyst for Low-temperature CO oxidation

Catalysts for CO oxidation reaction are mainly based on oxide/hydroxide materials with multicomponent active sites. Here, we report a non-oxide/hydroxide material, atomically dispersed dual-metal single sites (Fe-Co sites) on N-doped car-bon support, as a highly active catalyst for CO oxidation. It can greatly lower the temperature for complete CO conversion as low as -73oC with a turnover frequency (TOF) of 0.096 s-1. X-ray absorption near-edge structure (XANES) spectra, pulse-adsorption microcalorimetry and density functional theory (DFT) studies show that the Fe-Co sites synergistically catalyze CO oxidation facilely following the Langmuir-Hinshelwood (L-H) mechanism with CO preferentially adsorbing at the Co sites and O2 adsorbing at the Fe sites. These results for the first time reveal that the dual-metal single site on N-doped carbon can efficiency catalyze low-temperature CO oxidation reaction without the involvement of supports, such as oxygen vacancies and surface hydroxyl groups.