Synthesis and electrochemical study of Pt-based nanoporous materials

In the present work, a variety of Pt-based bimetallic nanostructured materials including nanoporous Pt. Pt-Ru, Pt-Ir. Pt-Pd and Pt-Pb networks have been directly grown on titanium Substrates via a facile hydrothermal method. The as-fabricated electrodes were characterized by scanning electron microscopy. energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and electrochemical methods. The active surface areas of these nanoporous Pt-based alloy catalysts are increased by over 68 (Pt-Pd), 69 (Pt-Ru) and 113 (Pt-Ir) fold compared to a polycrystalline Pt electrode. All these synthesized nanoporous electrodes exhibit superb electrocatalytic performance towards electrochemical oxidation of methanol and formic acid. Among the five nanoporous Pt-based electrodes, the Pt-Ir shows the highest peak Current density at +0.50V, with 68 times of enhancement compared to the polycrystalline Pt for methanol oxidation, and with 86 times of enhancement in formic acid oxidation: whereas the catalytic activity of the nonoporous Pt-Pb electrode outperforms the other materials in formic acid oxidation at the low potential regions, delivering all enhanced Current density by 280-fold compared to the polycrystalline Pt at +0.15 V. The new approach described ill this study is Suitable for synthesizing a wide range of bi-metallic and tri-metallic nanoporous materials, desirable for electrochemical sensor design and potential application in fuel cells. (c) 2008 Elsevier Ltd. All rights reserved.