Stability of Carbon Supported Pd/C Catalyst in Direct Formic Acid Fuel Cell

In order to understand the reason for the poor electrocatalytic stability of the Pd/C catalyst for formic acid oxidation, the changes in the structure and the electrocatalytic performance of the Pd/C catalyst after dipping in the formic acid solution for a certain time were investigated using X-ray diffraction spectroscopy and electrochemical methods. It is found that the relative crystallinity of the Pd particles of Pd/C catalyst increases from 1. 73 to 3. 34 and the average size decreases from 4.4 nm to 1. 8 nm after dipping in formic acid solution for 15 d. The electrocatalytic activity and stability of the Pd/C catalyst for formic acid oxidation decrease. The peak current density of formic acid oxidation decreases from 9. 3 mA/cm(2) to 6. 7 mA/cm(2). It may. be due to the certain dissolution of Pd in the Pd/C catalyst and the catalytic decomposition of formic acid at the Pd/C catalyst. This result may supply a new approach for exploring the reason for the poor electrocatalytic stability of the Pd/C catalyst for the formic acid oxidation.