Qiu Peng, Yang Xin, Wang Wanhua, Wei Tong, Lu Yanying, Lin Jie, Yuan Zhihao, Jia Lichao, Li Jian, Chen Fanglin
Department of Mechanical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States.
Center for Fuel Cell Innovation, School of Materials Science and Engineering, State Key Lab of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
ACS Appl Mater Interfaces. 2020 Mar 25;12(12):13988-13995. doi: 10.1021/acsami.0c00922. Epub 2020 Mar 15.
Solid oxide fuel cells (SOFCs) can directly operate on hydrocarbon fuels such as natural gas; however, the widely used nickel-based anodes face grand challenges such as coking, sulfur poisoning, and redox instability. We report a novel double perovskite oxide SrCoFeMoO (SCFM) that possesses excellent redox reversibility and can be used as both the cathode and the anode. When heat-treated at 900 °C in a reducing environment, double perovskite phase SCFM transforms into a composite of the Ruddlesden-Popper structured oxide SrCoFeMoO (RP-SCFM) with the Co-Fe alloy nanoparticles homogeneously distributed on the surface of RP-SCFM. At 900 °C in an oxidizing atmosphere, the composite transforms back into the double perovskite phase SCFM. The excellent oxygen reduction reaction catalytic activity and mixed ionic-electronic conductivity make SCFM an excellent cathode material for SOFCs. When SCFM is used as the anode, excellent performance and stability are achieved upon either direct oxidation of methane as a fuel or operation with sulfur-containing fuels. The excellent redox reversibility coupled with outstanding electrical and catalytic properties manifested by SCFM will enable a broad application in energy conversion applications.
固体氧化物燃料电池（SOFCs）可以直接使用天然气等碳氢化合物燃料运行；然而，广泛使用的镍基阳极面临着诸如积碳、硫中毒和氧化还原不稳定性等重大挑战。我们报道了一种新型双钙钛矿氧化物SrCoFeMoO（SCFM），它具有优异的氧化还原可逆性，可同时用作阴极和阳极。当在还原环境中于900℃进行热处理时，双钙钛矿相SCFM转变为具有Ruddlesden-Popper结构氧化物SrCoFeMoO（RP-SCFM）的复合材料，其中Co-Fe合金纳米颗粒均匀分布在RP-SCFM表面。在900℃的氧化气氛中，该复合材料又变回双钙钛矿相SCFM。优异的氧还原反应催化活性和混合离子-电子导电性使SCFM成为SOFCs的优异阴极材料。当SCFM用作阳极时，无论是将甲烷直接氧化作为燃料还是使用含硫燃料运行，都能实现优异的性能和稳定性。SCFM所表现出的优异氧化还原可逆性以及出色的电学和催化性能将使其在能量转换应用中得到广泛应用。
