Removal of CO in excess hydrogen over CuO/Ce 1− xMn xO 2 catalysts

Abstract

Ce 1− x Mn x O 2 mixed oxides were used as supports for preparing 7%CuO/Ce 1− x Mn x O 2 catalysts by impregnation for the preferential oxidation (PROX) of CO in excess hydrogen. Incorporating an appropriate amount of manganese into CeO 2 to form Ce 1− x Mn x O 2 solution increased the mobility of lattice oxygen and improved performance of CuO/Ce 1− x Mn x O 2 catalysts in the PROX of CO. CO oxidation proceeded at the interfacial perimeter through an interaction between CuO clusters and Ce 1− x Mn x O 2, involving not only the redox behavior of CeO 2 but also that of MnO x . The PROX reaction was not weakened as the fraction of manganese incorporated in the 7%CuO/Ce 1− x Mn x O 2 catalysts increased up to 0.3. A small amount of doped Mn 4+ and an appropriate amount of incorporated Al 2O 3 could obtain a good candidate such as 7%CuO/Ce 0.9Mn 0.1O 2-20%Al 2O 3 for a PROX unit in a polymer electrolyte membrane fuel cell system for removing CO. Its activity was comparable with, and its selectivity was much larger than, that of the noble catalyst 5%Pt/Al 2O 3.