Anodic Oxidation of Butan-1-ol on Reduced Graphene Oxide-Supported Pd-Ag Nanoalloy for Fuel Cell Application

Abstract

Reduced graphene oxide (RGO)-supported bimetallic Pd x Ag y alloy nanoparticles of various compositions were synthesized by one-pot coreduction of respective precursors with hydrazine for use in the anode catalysis of oxidation of butan-1-ol in alkali. The as-synthesized catalyst materials were characterized by microscopic, spectroscopic, and diffraction techniques. Cyclic voltammetry (CV), chronoamperometry, and polarization studies infer that a few Pd x Ag y materials exhibit an enhanced and synergistic catalytic activity in reference to Pd and Ag nanomaterials. Among the various RGO composites of Pd x Ag y alloy on graphite support, the one containing the Pd 70 Ag 30 @RGO composite is the best in catalytic activity. The cycle life of the catalyst is found to be very high, and PdO and Ag 2 O are found to be generated in the catalyst material with little change in the catalytic capability during the 100th cycle of CV operation. The addition of Ag upto 30 atom % in the Pd x Ag y alloy causes greater formation of butyraldehyde and butyl butanoate among the various products. Larger atom % of Pd helps to form sodium butyrate and sodium carbonate, as evident from the ex situ Fourier transform infrared and high-performance liquid chromatography study of the product mixtures and the separate CV studies of the intermediate products. A suitable mechanism is also proposed to fit the findings.