Characterization and electrochemical properties of chromium-substituted pyrochlore Y2Ti2−x Cr x O7−δ

• Published in: Journal of sol-gel science and technology 2015-11, Vol.76 (2), p.428-435
• Main Authors: Hao, Chia-Kan, Hung, Hao-En, Lee, Chi-Shen
• Format: Article
• Language: English
• Subjects: Atomic beam spectroscopy; Carrier density; Carrier mobility; Chromium; Electrochemical analysis; Electron microscopes; Emissions control; Inductively coupled plasma; Ion currents; Ions; Oxidation; Sol-gel processes; Solid oxide fuel cells; Spectrum analysis; Valence; X ray photoelectron spectroscopy; X ray powder diffraction; X-ray diffraction
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-015-3791-4

Pyrochlore oxides Y2Ti2−xCrxO7−δ have been investigated as electrolyte for solid oxide fuel cell. The as-prepared powder was synthesized by sol–gel method and characterized by powder X-ray diffraction, scanning electron microscope/energy-dispersive spectroscopy, inductively coupled plasma atomic emission spectroscopy, temperature-programmed reduction and AC impedance. Y2Ti2−xCrxO7−δ existed in single phase in a range of 0 < x ≤ 0.8, and the cell parameters decreased as the amount of Cr dopant increased. XPS analyses indicate that the average oxidation state of Crn+ ions decreased with the increased Cr content. Measurements of ionic conductivities induced that the optimized performance was observed at x = 0.2 with 0.01 S/cm at 700 °C due to an optimized condition of carrier concentration and carrier mobility.Graphical AbstractY2Ti2−xCrxO7−δ existed in single phase in a range of 0 < x ≤ 0.8 and the optimized performance of ionic conductivity was observed at x = 0.2 with 0.01 S/cm at 700 °C.