Effective cleanup of CO in hydrogen by PROX over perovskite and mixed oxides

Abstract

Preferential oxidation of CO (PROX-CO) from hydrogen has been carried out over various oxides and perovskite catalysts namely CeO2, CuLaO2eCeO2, La2CuO4. Further, effect of loading of a small quantity of Pt in catalysts 0.1 wt% Pt/CeO2, 0.1 wt% Pt/La2CuO4, 0.1 wt% Pt/CuLaO2eCeO2 was examined with respect to its activity for PROX-CO. In order to improve the surface area of La2CuO4 a chitosan complex method was used for synthesis. The catalysts were characterized using XRD, SEM and BET-SA techniques. Chitosan complex method results in pervoskite with pure phase, porous structure and higher surface area of 16.3 m2/g compared to that of 3.8 m2/g obtained by co-precipitation synthesis method. La2CuO4 exhibited a considerable activity for CO oxidation with conversion of 91.7%. Whereas, 0.1 wt% Pt/CuLaO2eCeO2 catalyst exhibited CO conversion of 94.1% and selectivity of 87.1% at reaction temperature of 320 �C. The improved CO/H2 selectivity may be attributed to the promotion of water gas shift reaction at the interface of Pt-metal oxide besides the relatively higher oxidation activity of the metal oxides. The catalysts reported in this study with relatively higher CO conversion and selectivity with lower value of l ¼ 0.3 exhibit potential for effective cleanup of hydrogen gas to remove CO for fuel cell applications