Tuning the metal-support interaction in the thermal-resistant Au–CeO(2) catalysts for CO oxidation: influence of a mild N(2) pretreatment

Pretreatment is very important for altering the catalytic properties of the supported noble metal catalysts in many heterogeneous reactions. In this study, a simple and mild pretreatment with N(2) has been reported to re-activate the Au–CeO(2) catalysts that were prepared by a deposition–precipitation method followed by calcination at 600 °C. Upon N(2) pretreatment at 200 °C, the metal-support interaction between Au nanoparticles (NPs) and CeO(2) was observed with the evidence of particular coverage of Au nanoparticles by CeO(2), electronic interactions and changes in CO adsorption ability. As a result, the CO oxidation activity of the pretreated Au–CeO(2) catalysts largely improved compared with those without any pretreatment and even with those subjected to H(2) and O(2) pretreatments. N(2) pretreatment also makes the Au NPs more resistant to sintering at high temperature. Furthermore, this mild pretreatment strategy can provide a potential approach to improve the thermal stability of other supported noble metal catalysts.