Palladium and palladium–copper alloy nano particles as superior catalyst for electrochemical oxidation of methanol for fuel cell applications. (15th October 2016)

• Record Type: Journal Article
• Authors: Chowdhury, Sreya Roy; Mukherjee, Parthasarathi; Bhattachrya, Swapan kumar
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 38(2016)
• Page Start: 17072
• Page End: 17083
• Publication Date: 2016-10-15
• Subjects: Alloy nanoparticle -- Hydrothermal process -- Methanol oxidation -- Fuel cell -- Synergic electro catalytic effect -- Mechanistic pathway; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.05.239
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Monometallic Pd, Cu and bimetallic Pd98 Cu2, Pd94 Cu6, Pd86 Cu14 alloy nano particles with small average particle diameter (6–10 nm) are synthesised by facile single pot hydrothermal reduction with hydrazine solution at 75 °C in absence of any special capping agent. Synthesized nano-materials are characterized by X-ray, electron diffraction, different microscopic and electro-analytical studies. Graphite supported bimetallic Pdx Cu100-x alloy unlike mixed nano particles show synergistic and enhanced electro catalytic activity towards oxidation of methanol in alkali. The maximum specific peak current of 987 mA mg −1 and equilibrium exchange current of 5 × 10 −6 mA mg −1 of Pd obtained for Pd94 Cu6 alloy in the present work are much better than the corresponding values reported for Pdx Cu100-x composite and alloy materials. Cyclic voltammograms of possible intermediates like formaldehyde as well as sodium formate and ex-situ FTIR and chromatographic studies of reaction products reveal that Cu accelerates formation of formate rather than carbonate elucidating the plausible mechanism of the reaction. Highlights: Pd and Pdx Cu100-x nanocatalysts are synthesised by simple hydrothermal method without using any capping agent. The maximum specific peak current, 987 mA mg −1 for MOR is obtained for Pd94 Cu6 alloy. Increased electrochemical surface area of PdCu alloy enhances catalytically active sites which help MOR. By analysing the products of MOR reaction plausible mechanism of the reaction is proposed. Decrease in %d-band character of Pd in alloying with Cu helps methanol adsorption and formate formation causing synergic effect.