The adsorption and activation of CO molecules on ZrO2 catalysts having low-coordinated surface sites

The adsorption and activation of CO molecules on microcrystalline ZrO₂ were investigated by photoluminescence (PL), UV, FT-IR, and ESR measurements. The ZrO₂ catalysts degassed at high temperatures exhibited abnormal absorption and photoluminescence associated with the presence of low-coordinated surface sites. The addition of CO molecules onto the pretreated ZrO₂ catalysts led to the formation of various CO adsorption species. Moreover, increasing the contact time gave rise to polymeric radical anion species of CO showing that UV-irradiation of the ZrO₂ catalysts in the presence of CO promoted the formation of these radical anion species of CO.