Reactive adsorption of CO from low CO concentrations streams on the surface of Pd/CeO2 catalysts

Abstract

Abstract Reformate gas mixtures introduced into PEM fuel cells may contain traces of CO which can irreversibly poison electrocatalysts. A means to eliminate such traces of CO from reformate mixtures via reactive adsorption onto solid catalysts is described. The reactive adsorption/desorption characteristics of CO were investigated over Pd/CeO2 catalysts with respect of Pd loading and adsorption temperature employing in situ FTIR and transient MS techniques. Results showed that CO adsorption is enhanced with increasing Pd content or decreasing adsorption temperature. Production of CO2 during CO-TPD occurs in a bifuntional manner with the participation of both the metallic phase and the support. Although the adsorption of CO is limited upon interaction of 0.25%Pd/CeO2 catalyst with a reformate mixture, results demonstrate that elimination of residual CO, present in the exit of methanation (or oxidation) reactor, is feasible via successive cycles of CO adsorption and oxidation at 40\u202f°C.