(188n) Low Temperature Synthesis of Calcium Ruthenate Perovskites and Pyrochlores

Over the last few decades, perovskite and pyrochlore oxides have received attention as electrochemical reaction catalysts with considerable focus on their usability as catalysts for oxygen reduction and evolution [1,2]. However, much of the reported work has investigated using Pb and Bi ruthanate pyrochlores, which do not have the surface alkalinity required to operate room temperature anion exchange membrane fuel cells on the carbonate cycle [3]. This work describes efforts to synthesize a rare family of calcium ruthenate perovskites and pyrochlores for use as catalysts in a room temperature carbonate fuel cell. Low temperature pyrolysis under an air atmosphere was used to obtain the perovskite while the pyrochlore was synthesized using a hydrothermal route. Ample investigations were conducted towards optimizing the synthesis route, including variations in temperature, starting materials, pH, time, between others. Materials were characterized using x-ray diffraction and tested for electrical conductivity, thermal stability and pH stability.

References: 1. N. Beck, B. Steiger, G. Scherer and A. Wokaun, Fuel Cells 1 (2006) 26. 2. J. Prakash, D. Tryk and E. Yeager, J. Electrochem. Soc. 146 (1999) 4145. 3. J. Vega and W. Mustain, Electrochim. Acta 55 (2010) 1638.