Silica based hybrid organic-inorganic materials for PEMFC application

Abstract

It is of key importance to develop membrane assembly electrodes (MEAs) offering high conductivity, thermal stability and suitable performance in the fuel cell. The mesoporous materials functionalized with acid groups are appropriate candidates to improve membrane's properties. The goal of this work was to assess the addition of functionalized porous silica, bearing different acid groups, on the MEA performance in a PEM type single fuel cell. Ni59Nb40Pt0.6Fe0.4 -based amorphous alloys were applied as anode electrocatalysts. The synthesis of functionalized mesoporous silica (UGM-fx) with different acid groups, namely [SO3H], [COOH] and [PO(OH)2], was carried out following a nonaqueous sol gel method. The results showed that the MEA containing silica with PO(OH)2 groups leads to an outstanding fuel cell performance compared to that of the other organic groups-based MEAs and that it outperformed a commercial Pt-based sample. This might be due to the higher proton conductivity exhibited by the phosphonic groups.