Au/PO43-/TiO2 and PO43-/Au/TiO2 catalysts for CO oxidation: effect of synthesis details on catalytic performance
- ORNL
Supported gold catalysts are active for CO oxidation, but the high-temperature deactivation is a shortcoming that may constrain their applications. Herein, we attempted to address this problem by using phosphate-doped Au/TiO{sub 2} synthesized via two routes. In route I, Au/PO{sub 4}{sup 3-}/TiO{sub 2} catalysts were prepared by treating TiO{sub 2} (Degussa P25) with diluted H{sub 3}PO{sub 4}, followed by loading gold via deposition-precipitation. In route II, PO{sub 4}{sup 3-}/Au/TiO{sub 2} catalysts were prepared by treating H{sub 2}-reduced Au/TiO{sub 2} with diluted H{sub 3}PO{sub 4}. These catalysts were systematically pretreated at 200 or 500 C before reaction testing. The overall CO conversion on 200 C-pretreated Au/PO43-/TiO2 or PO43-/Au/TiO2 was always lower than that on 200 C-pretreated Au/TiO2. However, the advantage of the phosphate addition became apparent after thermal treatment at a higher temperature. Both Au/PO43-/TiO2 and PO43-/Au/TiO2 pretreated at 500 C retained significant activities at room temperature, whereas 500 C-pretreated Au/TiO2 lost its activity. Control experiments and catalyst characterization were performed to investigate the impact of synthesis details on catalytic performance.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 931729
- Journal Information:
- Applied Catalysis A, Vol. 327, Issue 2
- Country of Publication:
- United States
- Language:
- English
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