N-Coordinated Dual-Metal Single-Site Catalyst for Low-Temperature CO Oxidation

Abstract

Catalysts for CO oxidation reaction are mainly based on oxide/hydroxide materials with multicomponent active sites. Here, we report a nonoxide/hydroxide material, atomically dispersed dual-metal single sites (Fe–Co sites) on N-doped carbon support, as a highly active catalyst for CO oxidation. It can greatly lower the temperature for complete CO conversion as low as −73 °C with a turnover frequency of 0.096 s–1. X-ray absorption near-edge structure spectra, pulse-adsorption microcalorimetry, and density functional theory 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.