Pr2NiO4-Ag composite as cathode for low temperature solid oxide fuel cells: Effects of silver loading methods and amounts

Abstract

Active cathode materials for low temperature solid oxide fuel cells (SOFC) below 600 °C are urgently required due to the sluggish oxygen reduction reaction (ORR) kinetics at reduced temperature. In this work, a detailed experimental fabrication and characterization of silver modified Pr2NiO4 composite material for low temperature SOFC cathode catalyst with superior ionic conducting ceria-carbonate composite electrolyte was carried out. Pr2NiO4 was prepared by a co-precipitation method with NaOH as precipitant, and it was composited with silver to improve the electrode activity toward ORR through three various methods of impregnation, solid-state mixing and freeze-drying, respectively. Effects of Ag loading on the electrochemical activity were systematically investigated. It was found that composite materials originated from impregnation method presented the optimal material microstructure, and 15% Ag loaded composite gave the lowest area specific resistance of 0.45 Ω cm2 at 600 °C, which is reduced by around 300% compared with previous work, indicating that impregnated Pr2NiO4-15Ag composite is a promising cathode catalyst for low temperature SOFC with ceria-carbonate composite electrolyte.