Hybrid membranes for formic acid fuel cells

最早的燃料电池市场出现在便携式领域，因为小型燃料电池具有比电池更高的固有能量密度。Tekion致力于便携式电源应用能源系统的商业化。然而，他们的微型燃料电池的改进是保持竞争优势的关键。该项目的目的是改进Tekion FormiraTM燃料电池，该电池依赖于甲酸燃料电池。为了实现这一目标，酸甲酸通过膜的渗透必须减少至少20%。本项目首次对甲酸燃料电池用Nafion膜进行了改进，并提出了Nafion混合膜的发展方向。我们的策略是将Nafion离聚体与无机双功能填料（吸湿性和质子导体）混合，在不妨碍离子电导率的情况下防止或减少甲酸的交叉。将使用两种双功能填料：水合氧化钌、RuO2。xH2O是一种混合电子-质子导体，质子传输活化能比Nafion低四倍；改性Faujasite沸石是一种高表面积分子筛，将被酸稳定（脱铝）并与含有磺酸基的有机基团官能化，以提高它们的质子导电性。不同配置的混合Nafion / RuO2。采用溶剂铸造法制备xH2O和Nafion /改性Faujasite沸石。将优化制备工艺，以降低甲酸交叉，同时保持不过度影响膜阻力。

The earliest market for fuel cells is seen in the portable sector because small fuel cells have an inherent higher energy density than batteries. Tekion is engaged in the commercialization of an energy system for portable power applications. However, improvement of their micro fuel cell is crucial to maintain their competitive edge. It is the aim of this project to improve the Tekion FormiraTM fuel cell which relies on a formic acid fuel cell. To achieve this objective, acid formic permeation through the membrane has to be reduced by at least 20%. This project addresses for the first time the improvement of Nafion membranes for formic acid fuel cells and the development of Nafion hybrid membranes is proposed. Our strategy rely on mixing the Nafion ionomer with inorganic bi-functional fillers (both hygroscopic and proton conductors) that will prevent or diminish formic acid cross-over without hampering the ionic conductivity. Two types of bi-functional fillers will be used: hydrous ruthenium oxide, RuO2.xH2O, a mixed electronic-protonic conductor with four times lower activation energy for proton transport than Nafion, and modified Faujasite zeolites, a high surface area molecular sieve, that will be acid stabilised (dealuminated) and functionalised with organic moieties containing sulfonic acid groups to improve their proton conductivity. Different configurations of mixed Nafion / RuO2.xH2O and Nafion / modified Faujasite zeolites will be prepared by solvent casting. The preparation procedure will be optimized to lower formic acid cross-over while maintaining without unduly affecting the membrane resistance.