Synthesis and conductivity of Ba(Ce,Zr,Y)O3−δ electrolytes for PCFCs by new nitrate-free combustion method

A new acetate–H2O2 combustion method was developed to synthesize BaCe0.8−xZrxY0.2O3−δ (x = 0, 0.1, 0.4, 0.6 and 0.8) electrolyte membranes for proton ceramic fuel cells (PCFCs). The new method offers a cost effective, simple and environmentally friendly preparation route, which avoids the emission of NOx gases that are typical of traditional nitrate precursor routes. The route should also be applicable for the synthesis of other multi-element ceramic-oxide materials. Phase purity, compositional accuracy and powder morphology were investigated by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) respectively. The novel combustion route produces powders with a fine crystallite size of 10–20 nm as synthesized, and 30–60 nm calcined. The presence of an intermediate peroxy (–OOH) bond has been identified by FT-IR and is suggested to aid the combustion reaction by harnessing the required oxidant in the form of labile peroxide complexes. The proton conductivities of the formed BaCe0.8−xZrxY0.2O3−δ electrolytes were measured in the temperature range of 100–900 °C under wet N2 atmosphere and shown to correspond with literature data.