The Study Of Anode Catalyst Pd/C For Direct Formic Acid Fuel Cell

Direct formic acid fuel cell (DFAFC) has been paid more attention in the recent years due to its advantages of high theoretical open circuit potential, limited fuel crossover, and reasonable power densities at low-temperature.The highly active Pd/C catalysts and Pd-Ir/C catalysts for electrooxidation of formic acid have been prepared by a waterless polyol process and a microwave- assisted polyol process, respectively. The particle size, lattice parameter, composition, and micro-morphology of the Pd/C catalysts were determined by X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), and transmission electron microscopy (TEM), respectively. Their electrochemical performances for formic acid electrooxidation have been tested by cyclic voltammetry, chronoamperometry, and amperometric i-t curves.The results of electrochemical measurements show that the Pd/C catalyst prepared by waterless polyol process at the pH value of 10, the reducing temperature of 120℃and the reaction time of 3 hours exhibits the highest catalytic activity and stability for formic acid electrooxidation.The measurement results show that Pd/C catalyst prepared by the microwave- assisted polyol process at the pH value of 10 and a reaction time of 50 s has the best performance. It has the better electrocatalytic activity and stability for formic acid electrooxidation compared with that synthesized by conventional heating polyol process and impregnation reduction method.The Pd-Ir/C catalyst was also prepared by the microwave- assisted polyol process. The Pd-Ir/C catalyst with the suitable atomic ratio of Pd and Ir =5:1 prepared at the pH value of 10 has the better catalytic activity for the oxidation of formic acid than the Pd/C catalyst.