Deactivation of nanosize gold supported on zirconia in CO oxidation

Abstract An Au/ZrO 2 catalyst containing nanosize gold was investigated with respect to its activity in CO oxidation. The high initial activity observed at temperatures down to 230 K was followed by a gradual decrease. Two main reasons for the catalyst deactivation were found: (i) adsorption of CO and its accumulation as carbonates, this deactivation being reversible and after heating the catalyst surface being restored by CO 2 evolution, (ii) agglomeration of Au particles, which causes irreversible however weak deactivation. IR, XPS and TPD data were provided in support of a probable model of CO oxidation and deactivation on Au/ZrO 2 catalyst.