Electroactivity of titanium-supported nanoporous Pd–Pt catalysts towards formic acid oxidation

详细信息	查看全文 | 推荐本文 |

• 作者：Qingfeng Yi ; Wu Huang ; Xiaoping Liu ; Guorong Xu ; Zhihua Zhou ; Aicheng Chen
• 关键词：Nanoporous palladium ; Bimetallic Pt– ; Pd ; Formic acid oxidation ; Titanium substrate
• 刊名：Journal of Electroanalytical Chemistry
• 出版年：2008
• 期刊代码：27_00220728
• 类别：ph
• 出版时间：15 July 2008
• 卷：619-620
• 期：Complete
• 页码：197-205
• 文件大小：1884 K

摘要

Titanium-supported nanoporous network Pd/Ti (nanoPd/Ti) and bimetallic Pt–Pd/Ti (Pt₆₂Pd₃₈/Ti and Pt₅₀Pd₅₀/Ti) prepared by the hydrothermal process using formaldehyde as the reduction agent, were examined as electrocatalysts for the electrooxidation of formic acid. The electrocatalytic activities of the catalysts with high surface areas were evaluated in sulfuric acid solution containing 0.5 M formic acid using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectra (EIS). The three catalysts exhibited significantly high current densities of formic acid oxidation compared to the pure Pt or Pd catalyst. Formic acid oxidation on the nanoPd/Ti commences at a much lower potential than the Pt₆₂Pd₃₈/Ti and Pt₅₀Pd₅₀/Ti. These results are consistent with the analysis for the EIS of the catalysts. The EIS of nanoPd/Ti showed low charge-transfer resistances at low anodic potentials while low electrochemical impedances were observed at high potentials for the bimetallic Pt₆₂Pd₃₈/Ti and Pt₅₀Pd₅₀/Ti catalysts. It is suggested that the electrooxidation of formic acid on the nanoPd/Ti mainly follows the “direct pathway” while it follows the “indirect CO pathway” on the bimetallic Pt–Pd/Ti catalysts.