School of Materials Science and Engineering, Center for Innovative Fuel Cell and Battery Technologies, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA.
Nat Commun. 2011 Jun 21;2:357. doi: 10.1038/ncomms1359.
The existing Ni-yttria-stabilized zirconia anodes in solid oxide fuel cells (SOFCs) perform poorly in carbon-containing fuels because of coking and deactivation at desired operating temperatures. Here we report a new anode with nanostructured barium oxide/nickel (BaO/Ni) interfaces for low-cost SOFCs, demonstrating high power density and stability in C(3)H(8), CO and gasified carbon fuels at 750°C. Synchrotron-based X-ray analyses and microscopy reveal that nanosized BaO islands grow on the Ni surface, creating numerous nanostructured BaO/Ni interfaces that readily adsorb water and facilitate water-mediated carbon removal reactions. Density functional theory calculations predict that the dissociated OH from H(2)O on BaO reacts with C on Ni near the BaO/Ni interface to produce CO and H species, which are then electrochemically oxidized at the triple-phase boundaries of the anode. This anode offers potential for ushering in a new generation of SOFCs for efficient, low-emission conversion of readily available fuels to electricity.
在固体氧化物燃料电池(SOFC)中,现有的掺镍氧化钇稳定氧化锆(Ni-YSZ)阳极在含碳燃料中的性能较差,因为在所需的工作温度下会发生结焦和失活。在这里,我们报道了一种用于低成本 SOFC 的具有纳米结构氧化钡/镍(BaO/Ni)界面的新型阳极,该阳极在 750°C 的 C(3)H(8)、CO 和气化碳燃料中表现出高功率密度和稳定性。基于同步加速器的 X 射线分析和显微镜揭示,纳米尺寸的 BaO 岛在 Ni 表面生长,形成了许多纳米结构的 BaO/Ni 界面,这些界面易于吸附水并促进水介导的碳去除反应。密度泛函理论计算预测,H(2)O 在 BaO 上离解的 OH 与 Ni 上靠近 BaO/Ni 界面的 C 反应,生成 CO 和 H 物种,然后在阳极的三相边界处进行电化学氧化。这种阳极有望为高效、低排放的燃料转化为电能带来新一代 SOFC。