Promotion of Pt/γ-Al2O3 by Ce for preferential oxidation of CO in H2

Hydrogen for fuel cells can be produced by reforming hydrocarbons. The H-2-rich reformate typically contains about 1 mol% CO which will poison the anode of polymer electrolyte fuel cells. The CO concentration can be reduced by preferential oxidation (PROX) using near-stoichiometric amounts of O-2. The conversion of CO should be over 99% while minimizing oxidation of H-2. Supported Pt catalysts with and without promotion by Ce were compared for the catalytic oxidation of CO by O-2 in a H-2 stream. With unsupported Pt catalysts, selectivity (to CO2 as opposed to H2O) was highest at low temperatures and low O-2/CO ratios, however conversion was low. Addition of Ce significantly improved CO conversion under these conditions.