Papers by Keyword: Samarium Doped Ceria SDC

Abstract: In this work ion conductivity and FC application were studied for the new type composite material based on SDC (samarium doped ceria) and Li2SO4. Significant conductivity enhancement was achieved, e.g. 10-2 – 0.4 Scm-1 for the SDC-Li2SO4 compared to 10-4 -10-2 Scm-1 for the SDC between 400 and 650°C. Some ion conductivity mechanisms were proposed correspondingly. Using the SDC-Li2SO4 composite materials as the electrolytes, we achieved high performances, 200-540 mWcm-2, for intermediate temperature (450-650°C) solid oxide FC (ITSOFC) applications. Sulfates, typically Li2SO4, have an excellent chemical stability in sulfur containing atmosphere. The sulfate-ceria (SDC-Li2SO4) composite materials can thus meet the demands to develop the sulfur tolerant and H2S FC technologies, which was also demonstrated successfully with significant importance for both fundamental and applied research.

Abstract: Steady generation of electricity (360 mW cm-2 at 1173 K) with dry methane fuel was successfully performed in solid oxide fuel cells (SOFC) by Pd-Ni bimetallic catalyst on porous composite anode prepared from La0.8Sr0.2CrO3 (LSCr) and Ce0.8Sm0.2O1.9 (SDC) (50:50 wt%). The amounts of carbon deposition were quite small under the open and closed circuit conditions. Synergy of Pd and Ni electrocatalysts was observed on the LSCr-SDC anode for the oxidation of dry methane. A small amount of carbon deposition over the anode during the open circuit conditions could be easily and quickly removed by gasification with steam. Data of detailed kinetic studies and electrochemical analysis strongly suggest that (i) methane decompose to hydrogen and carbon over the Pd-Ni catalyst, (ii) hydrogen is electrochemically oxidized with O2- to water, and (iii) carbon is quickly reformed with water to hydrogen and carbon oxides.