A study of CO removal on an activated Ru catalyst for polymer electrolyte fuel cell applications Original Research Article

The influence of pre-treatment of a Ru/Al2O3 catalyst on the CO preferential oxidation activity was studied for the residential polymer electrolyte fuel cell (PEFC) cogeneration system. When a Ru/Al2O3 catalyst was heated in a H2/N2 mixed gas flow as the pre-treatment, the CO oxidation activity was highly improved at a low temperature range. When an activated Ru/Al2O3 catalyst was used with the pre-treatment, CO was removed from the simulated reformed gas to less than 6 ppm at [O2]/[CO]=1.0 and to less than 0.5 ppm at [O2]/[CO]=1.5. However, CO was not removed to below 10 ppm at [O2]/[CO]=1.5 on a non-activated Ru/Al2O3 catalyst without the pre-treatment. The temperature window, where CO was removed to below 10 ppm, of the activated Ru/Al2O3 catalyst was between ca. 90 °C and ca. 140 °C at [O2]/[CO]=1.0 and between ca. 85 °C and ca. 170 °C at [O2]/[CO]=1.5, while that of the non-activated Ru catalyst was between ca. 155 °C and ca. 180 °C at [O2]/[CO]=3.0.