直接甲酸燃料电池炭载Pd阳极催化剂的稳定性

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

用X射线衍射和电化学方法研究了在甲酸溶液中浸泡一段时间后的Pd/C催化剂的结构和电催化性能,发现在甲酸溶液中浸泡15 d后,Pd/C催化剂中Pd粒子的相对结晶度由1.73增加到3.34,平均粒径由4.4 nm降低到1.8 nm,对甲酸氧化的电催化活性和稳定性降低,甲酸氧化的峰电流密度由9.3 mA/cm2降低到6.7 mA/cm2.这可能是由Pd/C催化剂中的Pd在甲酸中会有一定的溶解和Pd/C催化剂能催化分解甲酸引起的.

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/cm2 to 6.7 mA/cm2. 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.