Effects of Reduction Methods on the Performance of Shewanella oneidensis MR-1 Palladium/Carbon Catalyst for Oxygen Reduction Reaction

Abstract

The influence of the reduction method on the morphology and performance of the catalyst still controversial. In this study, hydrogen, Shewanella oneidensis MR-1 (MR-1), MR-1 and hydrogen coreduction are used to reduce the palladium ions adsorbed by MR-1 to obtain Pd/C H 2 , Pd/C M , and Pd/C H 2 +M catalyst, respectively. It is found that the palladium nanoparticles (Pd NPs) in Pd/C H 2 +M are the largest, while the Pd NPs in Pd/C M are the smallest. This is due to the reduction of Pd NPs in Pd/C H 2 +M under anaerobic conditions to form smaller Pd NPs that will further aggregate and grow in H 2 . In addition, Pd/C M exhibited the best catalytic performance with a mass activity of 0.31 A mg –1 , better than that of Pd/C H 2 (0.06 A mg –1 ) and Pd/C H 2 +M (0.13 A mg –1 ). This study provides a meaningful reference for the selection of reduction methods in metal catalysts.