Selective CO-Oxidation over Ru-Based Catalysts in H2-Rich Gas for Fuel Cell Applications

Ru-based catalysts supported on A zeolites and alumina were synthesised, characterised (XRD, SEM-EDS, TPR) and tested under realistic conditions for the preferential oxidation of CO (CO-PROX) from the hydrogen-rich gas streams produced by fossil fuels reforming. Comparative tests with a commercial catalyst were also carried out with special attention to the detection of possible side reactions (i.e. methanation and return water gas shift). The 0.5%Ru–Al₂O₃ catalyst resulted the most active, the most selective and the least prone to side reactions; methanation, in particular, was found to occur only when the catalyst is oxidised because of occasional exposure to O₂-rich streams.