Effect of Oxygen Vacancy on CO−NO−O2 Reaction over Yttria-Stabilized Zirconia-Supported Copper Oxide Catalyst

• Published in: Industrial & engineering chemistry research 1997-05, Vol.36 (5), p.1544-1551
• Main Authors: Chien, Chin-Cheng, Shi, Jing-Zhen, Huang, Ta-Jen
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheric pollution; Exact sciences and technology; General processes of purification and dust removal; Pollution; Prevention and purification methods
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie9602724

The effect of oxygen vacancy on the enhancement of activity of CO−NO−O2 reaction over yttria-stabilized zirconia (YSZ)-supported CuO catalyst was investigated in the present study. The catalysts were prepared by the impregnation method, and their characteristics were studied by temperature-programmed reduction. The catalyst was placed in a flow reactor for performing the temperature-programmed reaction, and the effluent gas was analyzed by an on-line NO x analyzer, consisting of a chemiluminescence unit and two gas chromatographs in series. The present results indicate that copper oxide supported by YSZ exhibits a higher catalytic activity than that supported by α-Al2O3, for the CO−NO−O2 reaction. The enhanced activity is inferred to result from the formation of interfacial Cu2O and the oxygen-ion transfer. Additionally, the probable effect of oxygen vacancy in promoting the CO−O2 or CO−NO2 reaction has been elucidated by a mechanism involving oxygen-ion transfer via surface oxygen vacancies of YSZ, which are located at the interface between CuO and YSZ. It was found that the CuO/YSZ catalyst is a promising substitute for the conventional Rh/alumina catalyst.