New Electrochemical Approach for the Synthesis of Pd- PdO/C Electrocatalyst and Application to Formic Acid Electrooxidation

摘要

Pd-PdO/C catalyst for formic acid electrooxidation has been synthesized via electrochemical dispersion of Pd foil electrodes under pulse alternating current conditions in NaCl aqueous electrolyte. About 35 wt% of the as-prepared Pd-PdO/C speci- men is PdO as revealed by X-ray diffraction. The microstructural characteristics and catalytic activity of the synthesized Pd/C catalyst have been compared with those of a Pt/C catalyst prepared under the same conditions. Pd nanoparticles of Pd- PdO/C catalyst exhibit smaller average dimensions and nar- rower particle size distribution - 7.4?0.5 nm and 1.9?0.5 respectively for Pd and PdO particles. The process of ethanol electrooxidation on the catalyst was characterized by high overvoltage (up to 800 mV). The overvoltage of the formic acid electrochemical oxidation on Pd/C is 590 mV less than on Pt/C.