Affiliation: Instituto de Química de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador SaoCarlense, 400 CP 780, 13560-970 São Carlos, Sao Paulo, Brazil.
Nanomaterials are receiving great attention in terms of research and development over the past few years in Polymeric Electrolyte Membrane (PEM) for Fuel Cells and Electrolyzers applications. The addition of inorganic nanofillers (SiO2, ZrO,sub>2 and TiO2), clays (montmorrillonite, bentonite, etc.), heteropolyacids (including cesium salts) and carbon nanotubes to the membrane structure have demonstrated to be ways of enhancing the system performance. In H2- based PEMFC, the water retention capacity can be significantly increased, opening up the possibility of operating the system above the water boiling point under low humidity conditions without a dramatic drop in the performance. In Direct Alcohol Fuel Cell (DAFC), its application intends to address the detrimental alcohol crossover that depolarizes the cathode without inadmissibly depressing the membrane conductivity. Good results can be obtained when including SiO2 and TiO2 nanoparticles, metallic nanoparticles, zeolites and clays such as plain and sulfonated-montmorillonite. For high temperature PEMFC based on phosphoric acid-doped polybenzimdazole, the presence of the nanocomponents helps to achieve higher conductivities compared to the pristine material under severe anhydrous conditions, which is reflected in larger power density peaks. Finally, a section for the PEM electrolyzer depicts the importance of SiO2 and TiO2 nanoparticles for improving the performance of this system without the additional consumption of electricity by allowing the operation above 100 °C.