Cationic Ag+ and Agnδ+ species are active sites in low temperature CO oxidation.
An appropriate Si/Al ratio is essential for CO oxidation over supported Ag catalyst.
Broensted acidity of zeolite correlates with the catalyst activity.
Consecutive oxidizing and reducing pretreatments promote catalytic activity.
Ag/ZSM-5 (80) catalyst displayed the highest activity in CO oxidation.