Low-temperature CO preferential oxidation in H2-rich stream over iron modified Pd-Cu/ hydroxyapatite catalyst

The effect of FeCl3 addition on the catalytic property of Pd-Cu/hydroxyapatite (Pd-Cu/ HAP) for low-temperature CO preferential oxidation (CO-PROX) under H2-rich condition has been investigated. It can be found that CO conversion of Pd-Cu/HAP rapidly decreases from 56% to 21% within 2 hat 30 degrees C in the presence of water, however, the Pd-Cu-Fe/HAP with the Fe/Cu atomic ratio of 1:1 presents a stable CO conversion of 40% and CO2 selectivity of 100% under the same reaction conditions. The characterization results display that the addition of FeCl3 to Pd-Cu/HAP causes the formation of Fe2O3 species, and the strong interaction presents between Fe2O3 species and Pd-Cu/HAP. Thus, the Pd0 species generated during CO-PROX over Pd-Cu-Fe/HAP can be more easily oxidized than that over Pd-Cu/HAP, which could avoid H2 adsorption on Pd0 species and maintain CO adsorption and activation. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. <comment>Superscript/Subscript Available</comment