Anode-supported proton-conducting fuel cell with BaZr(0.1)Ce(0.7)Y(0.2)O(3-delta) (BZCY) electrolyte and Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-delta) (BSCF) cathode was fabricated. Peak power densities of similar to 420 and 135 mW/cm(2) were achieved, respectively, at 700 and 450 degrees C for a cell with 35 gm thick electrolyte operating on hydrogen fuel. The endothermic nature of the ammonia decomposition reaction, however, resulted in cell temperature 30-65 degrees 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 NH(3) catalytic decomposition. By applying on-line catalytic decomposition products of N(2)H(4) as the fuel, similar cell performance to that with NH(3) fuel was also observed. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.