Proton-conducting fuel cells operating on hydrogen, ammonia and hydrazine at intermediate temperatures

Abstract

Anode-supported proton-conducting fuel cell with BaZr0.1Ce0.7Y0.2O3-d (BZCY) electrolyte and Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF) cathode was fabricated. Peak power densities of ~420 and 135 mW/cm2 were achieved, respectively, at 700 and 450 °C for a cell with 35 µm thick electrolyte operating on hydrogen fuel. The endothermic nature of the ammonia decomposition reaction, however, resulted in cell temperature 30-65 °C lower than the furnace when operating on ammonia. Accounting the cooling effect, comparable power density was achieved for the cell operating on ammonia and hydrogen at high temperature. At reduced temperature, the cell demonstrated worse performance when operating on ammonia than on hydrogen due to the poor activity of the anode towards NH3 catalytic decomposition. By applying on-line catalytic decomposition products of N2H4 as the fuel, similar cell performance to that with NH3 fuel was also observed. © 2009 Professor T. Nejat Veziroglu.