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

Abstract

Abstract A calcium-doped ceria with nominal compositions of Ce 1-x Ca x O 2-δ (0.00 ≤ x ≤ 0.30) has been developed as an anode component for solid oxide fuel cells running on methane fuel. Crystal phases of Ce 1-x Ca x O 2-δ are investigated with respect to the amount of calcium dopant. The Ce 1-x Ca x O 2-δ 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 Ce 1-x Ca x O 2-δ ceramics are studied by a four-probe method in air and the composition of Ce 0.9 Ca 0.1 O 2-δ (x = 0.10) is found exhibiting the highest conductivity among the samples investigated in this work. Electrocatalytic properties of Ce 0.9 Ca 0.1 O 2-δ are evaluated based on Ni-Ce 1-x Ca x O 2-δ anode supported single cell running on methane fuel. At 800 °C, the single cell with Ni-Ce 0.9 Ca 0.1 O 2-δ (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-Ce 0.9 Ca 0.1 O 2-δ anode for electrochemical oxidation of methane fuel.