Structural changes in NiO-Ce0.8Sm0.2O2−x anode under reducing atmosphere

Abstract One step formation of NiO-Ce 0.8 Sm 0.2 O 2−x is realized by auto-combustion method. Subsequently the powders are reduced by hydrogen at 500, 700 and 900 °C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the reduction of NiO to Ni at mentioned temperatures. X-ray photoelectron spectroscopy (XPS) results show higher selectivity reaction of NiO to Ni at elevated temperature in hydrogen stream which may trigger the reduction of Ce 4+ to Ce 3+ . Reduction of oxygen lattice as well as increment of Ce 3+ in Ce oxide structure in a reducing atmosphere demonstrate formation of higher oxygen vacancies concentration at lower temperatures.