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J Mater Sci: Mater Electron (2017) 28:778786 DOI 10.1007/s10854-016-5590-2
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Web End = Naon/sulfonic acid functionalized SnO2/SiO2 nanocomposite for mitigation of membrane chemical degradation in PEM fuel cells
Mohammad Taghi Taghizadeh1 Morteza Vatanparast1
Received: 20 July 2016 / Accepted: 18 August 2016 / Published online: 20 August 2016 Springer Science+Business Media New York 2016
Abstract Chemical durability of membranes plays an important role for the lifetime and commercial viability of the proton exchange membrane (PEM) fuel cells. In this study, a novel nanocomposite membrane based on Naon and sulfonated SnO2/SiO2 (SnO2/SiO2SO3H) was prepared by the solution-casting method. The design of nanocomposite membrane was based on the mitigation of membrane chemical degradation while keeping the proton conductivity as high as possible. The water uptake, ion exchange capacity, proton conductivity and thermal stability of membranes were studied. The results revealed that the proton conductivity of the Naon/SnO2/SiO2SO3H membranes is slightly lower than those of the pure Naon membrane. However, the proton conductivity of the Naon/SnO2/SiO2SO3H membrane is higher than that of the un-sulfonated Naon/SnO2 membrane. Fentons test was used as an ex situ accelerated test to evaluate the chemical durability of membranes. The results indicate that the uoride release and weight loss in Naon/SnO2/SiO2
SO3H nanocomposite membranes are less than those in the pure Naon membrane, which indicates the more chemical durability of Naon/SnO2/SiO2SO3H nanocomposite membrane. These ndings were further conrmed by ATR
FTIR spectra and SEM surface images of membranes.
1 Introduction
The polymer electrolyte membrane (PEM) fuel cell is a promising technology due to its high energy efciency, convenient operation, and environmentally friendly characteristics [1]. In the last years, considerable researches have been made to improve the lifetime of PEM fuel cells [2]. Peruorosulfonic acid (PFSA) membranes (e.g. Naon) are the most commonly used electrolyte material for PEM fuel cells [3]. Chemical degradation of membrane is reported to be a major cause of PEM fuel cells lifetime limitations [46]. It is generally accepted that the causes of the membrane chemical degradation is the attack of hydroxyl radicals that are generated from hydrogen peroxide decomposition in the fuel cell environment [710]. The existence of hydrogen peroxide had been conrmed in situ during the fuel cell operating conditions [11, 12]. Radical attack of...