Synthesis and characterization of Gd3+ and Sm3+ ion doped ceria electrolytes through an in-situ sulphated combustion technique

Abstract

An in-situ sulphated-combustion synthesis is reported to obtain gadolinium [Ce0.9Gd0.1O1.95] and samarium [Ce0.9Sm0.1O1.95] doped ceria electrolytes for solid oxide fuel cells (SOFCs). Nitrate precursors of cerium, gadolinium and samarium reactants were mixed homogenously with a citric acid fuel with an in-situ addition of 10 and 20 mol% ammonium sulphate [(NH4)(2)SO4]. The mixture was combusted at 500 degrees C and subsequently calcined at 700 degrees C. The influence of the sulphate addition on the morphology of ceria particles has been analyzed. It is seen that the in-situ SO42- ions highly favors the nucleation and growth of doped ceria electrolytes on a nanometer scale with an added advantage of improved crystallinity. TEM analysis indicates loosely agglomerated and nearly spherically shaped ceria nano particles with a maximum particle size of 20 nm