Structural features and catalytic performance in CO preferential oxidation of CuO-CeO sub(2) supported on multi-walled carbon nanotubes

• Published in: Catalysis science & technology 2015-02, Vol.5 (3), p.1568-1579
• Main Authors: Gao, Yuxian, Xie, Kangmin, Wang, Wendong, Mi, Shiyang, Liu, Ning, Pan, Guoqiang, Huang, Weixin
• Format: Article
• Language: English
• Subjects: CARBON BASE MATERIALS; CARBON DIOXIDE; Carbon monoxide; Catalysis; CATALYSTS; CERIUM ALLOYS (0 TO 50 CE); Copper; COPPER OXIDE; Oxidation; Streams; TUBE; X RAY SPECTROSCOPY; X-ray photoelectron spectroscopy
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c4cy01220h

Multi-walled carbon nanotube (MWCNT) supported CuO-CeO sub(2) catalysts were prepared using an impregnation method aided by an ultrasonication treatment. The structural features of the catalysts were extensively characterized by XRD, TGA, H sub(2)-TPR, XPS, TEM and Raman spectroscopy. The catalytic performance in the preferential oxidation of CO in a H sub(2)-rich stream was extensively investigated with respect to the influences of Cu/Ce ratios, the different support materials and the presence of CO sub(2) and H sub(2)O in the feed stream. In contrast to those supported on other materials, the catalytic performance was greatly enhanced for the MWCNT-supported CuO-CeO sub(2) catalysts, which was discussed in terms of the synergistic interactions between Cu-Ce mixed oxides and MWCNT. The optimized catalyst with a Cu/Ce ratio of 5/5 can achieve complete CO conversion and high selectivity toward CO sub(2) in a wider temperature range as well as favorable performance under the simulated reformatted gas mixture. The deactivation of CuO-CeO sub(2) catalysts supported on MWCNT at elevated temperatures was also discussed in relation to the temperature-dependent in situ XAFS spectra during CO-PROX reaction.