Calcium-doped ceria materials for anode of solid oxide fuel cells running on methane fuel

A calcium-doped ceria with nominal compositions of Ce1-xCaxO2-delta (0.00 <= x <= 0.30) has been developed as an anode component for solid oxide fuel cells running on methane fuel. Crystal phases of Ce1-xCaxO2-delta are investigated with respect to the amount of calcium dopant. The Ce1-xCaxO2-delta shows single fluorite phase when the calcium is within 15 mol.%, and higher calcium doping levels lead to the appearance of a secondary phase (CaO). Conductivities of Ce1-xCaxO2-delta ceramics are studied by a four-probe method in air and the composition of Ce0.9Ca0.1O2-delta (x = 0.10) is found exhibiting the highest conductivity among the samples investigated in this work. Electrocatalytic properties of Ce0.9Ca0.1O2-delta are evaluated based on Ni-Ce1-xCaxO2-delta anode supported single cell running on methane fuel. At 800 degrees C, the single cell with Ni-Ce0.9Ca0.1O2-delta(x = 0.10) anode exhibits an optimum maximum powder density (618 mW cm(-2)) and good performance stability during 30 h operation in methane fuel. The promising findings substantiate the good performance of Ni-Ce0.9Ca0.1O2-delta anodefor electrochemical oxidation of methane fuel. (C) 2017 Elsevier B.V. All rights reserved.