The escalating levels of environmental pollution, driven by industrial activities and urban expansion, pose a signifi cant 

threat to global health and ecological balance. In response to this pressing challenge, the oxidation of pollutants has 

emerged as a crucial strategy for environmental remediation. This process involves transforming harmful substances 

into less toxic or benign products, often through reactions with oxidizing agents. Catalytic oxidation, in particular, off ers 

a promising approach, enabling effi cient and selective pollutant removal under relatively mild conditions. Developing 

eff ective catalysts is therefore paramount in the pursuit of cleaner air. This review critically examines various Ag-based 

catalytic systems, including supported Ag catalysts, Ag-doped oxides, bimetallic systems (e.g., Au-Ag), silver nanoclusters 

and single-atom catalysts for CO oxidation activity. Key strategies to enhance catalytic performance—such as tuning silver 

dispersion, modifying oxidation states, and employing diverse supports like silica, SBA-15, and activated carbon—are 

highlighted. The eff ect of pre-treatment conditions and the nature of oxygen species (surface vs. subsurface) are the critical

factors that aff ect the CO oxidation activity. Mechanistic insights reveal that both Langmuir-Hinshelwood and EleyRideal

pathways are operative, depending on catalyst composition, silver species (Ag +

 or Ag 0

 ), and reaction conditions. 

Additionally, the review underscores the structure-sensitive nature of the reaction and the critical role of coordinatively 

unsaturated Ag atoms.