Investigation of a Carbon-Supported Pt Electrode for Oxygen Reduction Reaction in 0.1M KOH Aqueous Solution

Abstract

The carbon-supported Pt nanoclusters (20 wt% metal) electrodes have been tested as oxygen reduction catalysts in 0.1M KOH solutions. The novel non-conventional microporous-mesoporous carbide derived carbon powder, synthesized from molybdenum carbide (Mo2C) at 750°C using the high-temperature chlorination method, has been used as an electrocatalyst support for oxygen electroreduction. For comparison, the corresponding parameters for commercially available VulcanXC72 and (20 wt%) Pt-VulcanXC72 have been obtained. Results of the X-ray diffraction analysis show that the Pt nanoclusters have been deposited mainly as the face-centered cubic (fcc) crystals at both carbon supports. The Pt particles were distributed uniformly on the porous carbon supports, and the average particle size of the Pt nanoclusters at (20 wt%) Pt-C(Mo2C) and at (20 wt%) Pt-VulcanXC72 were 42 and 57 Å, respectively. The (20 wt%) Pt-C(Mo2C) catalyst demonstrated higher activity (calculated effective electrochemical surface area Aeff = 0.485 cm2) with high specific surface area SBET = 1600 m2 g−1 toward the oxygen electroreduction reaction at room temperature compared with that for the (20 wt%) Pt-VulcanXC72 (Aeff = 0.320 cm2) with SBET = 180 m2 g−1. The four-electron oxygen reduction mechanism has been established for both, i.e., the (20 wt%) Pt-C(Mo2C) and (20 wt%) Pt-VulcanXC72 catalysts based electrodes.