The next generation solid acid fuel cell electrodes: stable, high performance with minimized catalyst loading

Abstract

Low electrode impedance paired with low catalyst loading in intermediate and low temperature fuel cells is extremely difficult to achieve, posing a major obstacle to commercialization. Here we demonstrate a scalable and facile route to obtain nanostructured composite solid acid fuel cell electrodes consisting of Pt decorated carbon nanotubes and CsH₂PO₄ microparticles as the electrolyte. Electrochemical impedance measurements in humidified hydrogen at 240 °C show very low 0.05 Ω cm² area normalized electrode resistance, with a Pt loading of only 0.41 mg_Pt cm⁻². This is a reduction of the Pt loading by more than one order of magnitude paired with even lower electrode impedance values compared to the current state-of-the-art in literature. Fuel-cell measurements show remarkably stable electrode performance over a 17 h period with a final degradation rate of 0.1% h⁻¹.