Synthesis And Performance Improvement Of Pd-based Anode Electrocatalyst In Alkaline Direct Methanol Fuel Cell

Direct methanol fuel cell(DMFC)is an electrochemical device that can directly convert the chemical energy stored in methanol into electrical energy.It has the characteristics of high energy conversion efficiency,abundant fuel sources,convenient transportation and storage,and low cost,and has broad application prospects.However,so far,it still faces some challenges that hinder its commercialization,including the high cost of catalysts,the poisoning effect of methanol oxidation intermediates,the slow methanol oxidation kinetics process,and methanol permeation.In order to improve the activity and anti-poisoning ability of the catalyst,a series of Pd-based nano electrocatalysts were prepared with carbon materials as the carrier and ethylene glycol as the reducing agent for electrooxidation of methanol in alkaline media.By introducing transition metal components(such as Ni and Cu)into the Pd-based catalyst,the dispersion of palladium nanoparticles on the surface of the carbon support can be improved,which is related to the oxide/hydrated oxide formed by the transition metal on the surface of the support.At the same time,X-ray photoelectron spectroscopy shows that the transition metal components have a synergistic effect on Pd nanoparticles,which helps to improve the methanol oxidation performance of Pd-based catalysts.Combining carbon carriers with different morphology and structural characteristics(such as carbon nanotubes,activated carbon black,graphene nanosheets,etc.)to construct a composite carbon carrier can effectively improve the spatial structure of the carbon carrier and increase the surface utilization of the carbon carrier The catalyst nano metal particles can be effectively dispersed,thereby increasing its electrochemical active surface area and improving methanol electrooxidation activity.Combining the synergistic effect of transition metal components and the structural effect of the composite carbon support,PdNi/CNTs-GNPs and PdCu/CNTs-GNPs catalysts were prepared,and the methanol electrooxidation performance was further improved.Studies have shown that the synergistic effect of the transition metal components and the spatial structure effect of the carbon support are of great significance to the improvement of the methanol oxidation performance of Pd-based catalysts.