Electrochemical Characterization of Palladium Supported in Thermally Treated Carbon for Oxygen Reduction Reaction in Acid Media

摘要

In proton exchange membrane fuel cell (PEMFC), the low interaction between the electrocatalyst and the support has been subjected of an intensive research in last years. The low interaction arises by a decreased contact between the support and the nano sized catalyst. In this paper the palladium supported in thermally treated carbon (Pd/TTC) was synthesized via the NaBH_4 reduction of the PdCl_2 precursor at 60℃. The supporting carbon was thermally treated at 200℃, 400℃, 600℃ and 800℃. Structural characterization of the TTC was examined by Raman spectroscopy and the Pd/TTC morphology by SEM. Electrocatalyst activity for the oxygen reduction reaction was investigated by cyclic and linear voltammetry in 0.5M H_2SO_4 at 25℃. The resulted Pd/TTC at 400℃and 600℃ showed significantly higher activity following kinetics of four electrons transfer to water formation. This behavior is attributed to structural properties and superficial conditions of the supporting carbon.