Selective low-temperature CO oxidation over Pt-Co-Ce/Al2O3 in hydrogen-rich streams

The selective low-temperature oxidation of CO was studied in hydrogen-rich streams over Pt-Co-Ce/Al2O3 catalysts, which were prepared using the incipient to wetness co-impregnation technique. The effects of reaction temperature and feed composition on CO conversion and selectivity were investigated in a flow micro-reactor system. The 100% CO conversion was achieved over 1.4 wt% Pt-1.25 wt% Co-1.25 wt% Ce/Al2O3 with significantly high selectivity at a reaction temperature of 90 °C using a feed composition of 1.0% CO, 1.0% O2, 60% H2 and He as balance at a space velocity of 24,000 cm3/(g h). Addition of 25% CO2 and 10% H2O into the feed increased the reaction temperature to 110 °C but allowed 100% CO conversion for 300 min time-on-stream. It was concluded that this catalyst may have great potential for removing CO in the hydrogen stream from a fuel processor for fuel cell applications, considering the fact that it may operate at significantly lower temperatures and O2/CO ratios compared to other alternatives reported in the literature.