Enhancement of redox stability and electrical conductivity by doping various metals on ceria, Ce1−xMxO2−δ (M = Ni, Cu, Co, Mn, Ti, Zr). (21st September 2015)

• Record Type: Journal Article
• Authors: Myung, Jae-ha; Shin, Tae Ho; Huang, Xiubing; Carins, George; Irvine, John T.S.
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 35(2015)
• Page Start: 12003
• Page End: 12008
• Publication Date: 2015-09-21
• Subjects: Ceria -- Impedance spectroscopy -- Electrical conductivity -- Oxide anode -- Solid oxide fuel cell; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.05.029
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Various metal oxide materials have been actively investigated to improve energy efficiency as exhaust-catalyst as well as electrodes in electrochemical devices such as fuel cells, ceramic sensors, photo-catalyst etc. Ceria-based materials are of great interest due to their wide applications; such as redox or oxygen storage promoter in automotive catalyst and solid state conductor in fuel cells. Here we report redox and electrical properties for Ce1−x Mx O2−δ (M = Ni, Cu, Co, Mn, Ti, Zr) by X-ray diffraction (XRD) and simultaneous thermo-gravimetric analysis (TGA). Among various system, Ce1−x Cux O2−δ and Ce1−x Nix O2−δ indicated relatively reversible redox behavior, although Cu 2+ and Ni 2+ had limited solid solubility in CeO2 . The enhancement of oxygen carrier concentration and electrical conductivity as well as electrochemical activity in the ceria lattice by the introduction of small amounts transition metal cations have been considered in this study. Ce0.7 Cu0.3 O2−δ showed about 1015 μmol[O2 ]/g of oxygen storage capacity (OSC) with high redox stability at 700 °C. We also demonstrated that Ce0.9 Ni0.1 O2−δ was used as an anode of the YSZ electrolyte supported SOFC single cell; the maximum power density was 0.15 W/cm 2 at 850 °C with hydrogen fuel. Highlights: Metal dopants (Ni, Cu, Co, Mn, Ti, Zr) were soluble in ceria lattice without secondary phases. Metal doped ceria oxide enhanced the oxygen storage capacity and electrical conductivity. Ni doped ceria anode for solid oxide fuel cell showed 0.15 W/cm 2 at 800 °C.