Research progress on high temperature activity and high humidity stability of CO oxidation catalysts

Carbon monoxide (CO), a harmful and poisonous air contaminant, frequently occurs in industrial environments, mining operations, and vehicle emissions. It presents a significant threat to human health and safety, especially in restricted areas such as mines, where CO levels may escalate to dangerous extents. Catalytic oxidation, which converts CO into harmless carbon dioxide (CO2), serves as an effective method for its removal. This process involves complex heterogeneous catalysis, with principal mechanisms including Langmuir–Hinshelwood (L-H), Eley-Rideal (E-R), and Mars-Van Krevelen (MvK) models. Research on CO oxidation catalysts spans various materials, such as precious metals, transition metals, composite oxides, carbon-based materials, molecular sieves, and metal–organic frameworks. However, in harsh environments such as mines, catalysts face challenges related to activity and stability, influenced by high temperatures, high humidity, and elevated CO concentrations. To enhance catalyst efficiency under these harsh conditions, strategies including alloying, support loading, surface modification and structural regulation have been developed. This review aims to summarize the latest progress on CO oxidation catalysts, the underlying reaction mechanisms, and optimization strategies, providing insights into efficient and economical methods for CO removal in hazardous environments.