Nafion/Surface Modified Ceria Hybrid Membranes for Fuel Cell Application

Abstract

Low chemical durability of proton exchange membranes is one the main factors limiting their lifetime in fuel cells. Ceria nanoparticles are the most common free radical scavengers. In this work, hybrid membranes based on Nafion-117 membrane and sulfonic or phosphoric acid functionalized ceria synthesized from various precursors were prepared by the in situ method for the first time. Ceria introduction led to a slight decrease in conductivity of hybrid membranes in contact with water. At the same time, conductivity of membranes containing sulfonic acid modified ceria exceeded that of the pristine Nafion-117 membrane at 30% relative humidity (RH). Hydrogen permeability decreased for composite membranes with ceria synthesized from cerium (III) nitrate, which correlates with their water uptake. In hydrogen-air fuel cells, membrane electrode assembly fabricated with the hybrid membrane containing ceria synthesized from cerium (IV) sulfate exhibited a peak power density of 433 mW/cm2 at a current density of 1080 mA/cm2, while operating at 60 °C and 70% RH. It was 1.5 times higher than for the pristine Nafion-117 membrane (287 mW/cm2 at a current density of 714 mA/cm2).

Recent developments of proton exchange membranes for PEMFC: A review

“…The most recommendable is the metal oxides because they can prevent membrane degradation to some extent and extends the durability of it. Number of oxides have been used to get the notable performance, one of them is the ceria (Ce) added because Ce has the ability to possess reversible redox reaction (Yurova et al, 2021). For instance, Velayutham et al performed an experiment on modifying Nafion with CeO 2 for DMFC and Baker et al developed for PEMFC; both the PEMs showed exceptional performance (Baker et al, 2014;Velayutham et al, 2017).…”

Improvement of Selectivity of RALEX-CM Membranes via Modification by Ceria with a Functionalized Surface

“…One of the promising dopants is ceria. Ceria-doped membranes are highly stable during fuel cell operation [ 32 , 33 ], effective in water purification by reverse osmosis [ 34 ] and nanofiltration, and even have antibacterial properties [ 35 ], which can favorably affect the stability and service life of membranes. The reason for the unique antioxidant and antibacterial properties of ceria is its ability to interact with highly reactive oxygen radicals (hydroxyl radicals, superoxide radicals, etc.)…”

Development of WO3–Nafion Based Membranes for Enabling Higher Water Retention at Low Humidity and Enhancing PEMFC Performance at Intermediate Temperature Operation

“…On the other hand, a wide variety of inorganic fillers have been used, especially fillers with hygroscopic properties, including metal oxides such as silicon oxide [43,44], titanium oxide [22,45], and zirconium oxide [46,47], nanostructured clay such as laponite [48] and montmorillonite [49], and carbon-based material such as graphene oxide [50,51] and carbon nanotubes [13]. Additionally, cerium oxide has been used to interact with the generated hydrogen peroxide and other reactive hydroxyl and superoxide radicals, which were generated at low temperatures to improve the Nafion's durability against these radicals and prevent Nafion degradation, and thus the power loss of the fuel cells [52]. Among the metal oxides, Tungsten oxide (WO 3 ) is stable in sulphuric acid media, and its effect on the performance of Nafion has been scarcely investigated.…”

“…used to interact with the generated hydrogen peroxide and other reactive hydroxyl and superoxide radicals, which were generated at low temperatures to improve the Nafion's durability against these radicals and prevent Nafion degradation, and thus the power loss of the fuel cells [52]. Among the metal oxides, Tungsten oxide (WO3) is stable in sulphuric acid media, and its effect on the performance of Nafion has been scarcely investigated.…”