The Effect of Reducing Agent for Synthesizing Palladium Nanoparticle on Carbon Nanotube Support and Its Superior Catalytic Activity towards Methanol Oxidation Reaction

Abstract

In this report, we have synthesized carbon nanotube supported palladium nanoparticles (CNT-Pd) by using different reducing agents such as sodium borohydride (SBH), hydrazine monohydrate (HY) and ascorbic acid (AA) for the methanol oxidation reaction (MOR) in alkaline media. The elemental and morphological properties of all catalysts are verified by HRTEM, XPS, and XRD. From the HRTEM images, it is found that CNT-Pd reduced by sodium borohydride CNT-Pd (SBH) exhibited a narrow size distribution of Pd nanoparticles (PdNPs) with an average size of 3.15 nm. The role of the reducing agents (SBH, HY, and AA) is investigated by applying them as anode catalysts for the methanol oxidation reaction (MOR) and it is found that the reducing agent remarkably affected the electrochemical activities. CNT-Pd (SBH) catalysts show the superior catalytic activity and durability towards MOR among all catalysts, which may be due to the Pd NPs in CNT-Pd (SBH) having a perfect crystal structure with a narrow size distribution.