Platinum particles supported on mesoporous carbons: fabrication and electrocatalytic performance in methanol-tolerant oxygen-reduction reactions.

Abstract

In this report, we describe the preparation and electrochemical characterization of a Pt electrocatalyst, which was synthesized from hexachloroplatinic acid, using the incipient wetness impregnation method. This carbon mesoporous materials (Pt-CMMs) electrocatalyst was used for catalyzing the oxidation of methanol and its oxygen-reduction reaction. The electrocatalytic oxidation of methanol was studied using linear-sweep voltammograms (LSV), polarization and chronoamperometric measurements. Phase characterizations and morphological analyses were performed using 3D excitation-emission fluorescent matrix (EEFM) spectroscopy, UV-Vis absorption measurements, and X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM) techniques; the ESEM system was equipped with an energy-dispersive spectrometer (EDS). The oxidation capacity measured using a LSV might explain the high activity exhibited by the Pt-CMM electrocatalysts in methanol-tolerant oxygen reduction, and the results demonstrated that the potential and current density of the main reaction peak of the Pt-CMMs electrocatalyst changed during the reaction. Moreover, EEFM spectroscopy and XRD were determined to be appropriate and effective methods for characterizing Pt clusters that enhance their intrinsic emission from Pt-CMMs electrocatalysts in electrocatalytic-treatment systems. Furthermore, the ESEM-EDS results showed that fresh Pt nanoparticles were highly dispersed on CMMs and featured a 20 nm diameter and a narrow particle-size distribution.