磷钨酸表面处理对燃料电池质子交换膜热稳定性的影响

Effect of Tungstophosphoric Acid Surface Treatment on the Thermal Stability of Proton Exchange Membrane for Fuel Cell

研究了磷钨酸掺杂改性后质子交换膜的热稳定性及热降解动力学,利用热重分析在氮气气氛下和升温速率分别为5℃、20℃和30℃时,采用Kissinger、Flynn-Wall-Ozawa、Friedman和Starink方法对磷钨酸改性后的非等温动力学数据进行了分析。热失重曲线显示磷钨酸改性后质子交换膜分解率达到5%和10%时,最低热降解温度分别为173.6℃和284.8℃。采用不同方法的计算结果显示,改性后膜分解反应受D2机理控制,表观活化能约为163.74 kJ/mol。改性前后膜的电导率(σ)分别为8.34×10-7S/cm及2.57×10-5S/cm。

The thermal stability and thermal degradation kinetics of proton-exchange membrane were investigated, when it was doped and modified by tungstophosphoric acid. Non-isothermal kinetic data of modified membrane were analyzed by the thermogravimetry analysis and the Kissinger,Flynn-Wall-Ozawa,Friedman and Starink method,under the conditions of nitrogen atomosphere and heating rate of 5 ℃,20 ℃ and 30 ℃. TG-DTG curves show that at the conversion rate of 5% and 10%,the lowest temperature of the thermal degradation is 173. 6 ℃ and 284. 8 ℃,respectively. The results calculated by various method indicate that the average value of apparent activation energy of modified membrane is about 163. 74 kJ/mol. The decomposition reaction of modified membrane is controlled by D2 mechanism,the conductivity of membrane before and after modified respectively is 8. 34 × 10-7S/cm and 2. 57 × 10-5S/cm.