Study On Pd, Co Based Anodic Catalysts For Direct Ethanol Fuel Cells Application

Abstract:Low noble metal Pd and transition metal Co, Ni show good electrocatalytic activity and stability for oxidation of ethanol. The electrocatalysts containing Co and Pd as the main active ingredient and with addition of WC, Ti4O7, Li2O,La2O3were prepared and characterized by physical and electrochemical measurements.High activity and Homogeneous-dispersed Co nano-composite materials were prepared by liquid phase reduction methods. We studied the influence factores for catalytic activity to optimize the preparation. The result revealed that the addition of low-cost WC into Co/C composite catalytic could significantly improve the electrode performance for ethanol oxidation. The analysis of electrochemical impedance spectrum and Ethanol oxidation product enhanced the results. The results strongly prove that the addition of Ti4O7to anode catalyst enhances the activity and stability of the catalysts for ethanol oxidation.In alkaline solutions, a single metal Pd/C catalytic materials show a high electrocatalytic activity for oxidation of ethanol. It has gradually becomed electrocatalyst materials to replace the noble metal Pt for ethanol electro-oxidation. The result revealed that the addition of low-cost WC and Ti4O7into Pd/C composite catalytic could significantly improve the electrode performance for ethanol oxidation. DEFCs were assembled and constant-current discharging tests were carried out by varying the current density from10to30mA·cm-2. The discharging results showed that at the same current density, the discharge voltage of the cell using Pd-Ti4O7-WC/C as anode catalyst is higher and the curve is more smooth than that of Pd-WC/C. The results strongly prove that the addition of Ti4O7to anode catalyst enhances the activity and stability of the catalysts for ethanol oxidation.Though Pd/C catalytic materials show a high electrocatalytic activity for oxidation of ethanol in alkaline solutions.The activity stability was not well and decreased rapidly when the ethanol oxydate adsorbed on anode. The result showed that the addition of low-cost Li2O and La2O3into Pd/C composite catalytic could significantly improve the electrode performance for ethanol oxidation and enhance the poisoning resistance.The GC results showed that acetaldehyde and acetic acid increased when Li2O and La2O3added into Pd/C.The results prove that the addition of Li2O and La2O3into Pd/C catalyst enhances the activity and poisoning resistance of the catalysts for ethanol oxidation.