CO oxidation over Au supported on Mn–ZSM5 and Mn–MOR

• Gold nanoparticles were introduced by deposition–precipitation on Mn–zeolites.
• Manganese exchanged in zeolites promotes the activity of gold-based catalysts.
• A reductive treatment of bimetallic catalysts enhances the catalytic activity.
• Au/Mn–mordenite catalysts showed the highest activity in CO oxidation.

Active gold catalysts for CO oxidation were obtained by the deposition–precipitation of gold on ZSM-5 and mordenite, both of them ion-exchanged with manganese. A strong promotion of Mn upon the activity of bimetallic Au/Mn catalysts was observed when compared with the monometallic Au–zeolites. In turn, when an in-situ reduction of the bimetallic catalysts was performed, a further increase in activity was observed. Characterizations suggested that smaller gold nanoparticles were stabilized in the bimetallic solids and that the reduction process caused a rearrangement of Au and Mn species on the catalyst surface.