Composition for use as an electrolyte in a protonic ceramic fuel cell and a fuel cell thereof

The present invention relates to a solid oxide fuel cell especially protonic ceramic fuel cell which can operate at intermediate temperature and fuel cell thereof. The composition comprising a formula BaCeZrYZnO or BaCeZrYPrO, wherein x=0.05, 0.1, 0.15, 0.2 or 0.25 to vary Zr and Y percentage at the B-site, and Ba=100%, Ce=70%; and Zn=5%.