Sulfur- and Coking-Tolerant Anodes for Solid Oxide Fuel Cells

Abstract

Sulfur- and Coking-tolerant Anodes for Solid Oxide Fuel Cells Zhijun Liu,1 Yucun Zhou,1 Weilin Zhang,1 Jie Hou,1 Xueyu Hu,1 Meilin Liu1, * 1 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States Solid oxide fuel cells (SOFCs) have potential to be one of the most efficient systems for direct conversion of a wide variety of chemical fuels into electricity. 1-3 However, the lack of sulfur- and coking-tolerant anodes still hinders the development of direct hydrocarbon-fueled SOFCs for efficient and cost-effective operation. The conventional Ni-based anodes may suffer from carbon deposition and sulfur poisoning when they are directly exposed to sulfur-containing hydrocarbon fuels, resulting in degradation in performance or even destruction of the anodes. 4-6 In this presentation, we will report a conventional Ni-Zr0.84Y0.16O2-δ (YSZ) anode decorated with Ce and Ba-based catalyst coatings to significantly enhance the sulfur and coking tolerance. Results suggest that the enhanced sulfur tolerance is attributed to the evenly distributed Ce-based catalyst on the inner surface of the porous Ni-YSZ anode while the enhanced coking tolerance is benefited from the Ba-based catalyst layer on the top of the anode. SOFCs with the catalysts-modified Ni-YSZ anodes show minimal degradation when hydrogen with 100 ppm H2S is used as the fuel. More importantly, stable operation is demonstrated for direct utilization of sulfur-containing liquid fuels (e.g., octane and gasoline). This work demonstrates the great potential of catalyst coatings for enhancing contaminant tolerance and durability of SOFC electrodes. Z. Wang, Y. Wang, D. Qin, Y. Gu, H. Yu, S. Tao, B. Qian and Y. Chao, J. Eur. Ceram. Soc. (2022). S. Sengodan, M. Liu, T.-H. Lim, J. Shin, M. Liu and G. Kim, J. Electrochem. Soc., 161, F668 (2014). Z. Cheng, J.-H. Wang, Y. Choi, L. Yang, M. C. Lin and M. Liu, Energy Environ. Sci., 4, 4380 (2011). T. Hays, A. M. Hussain, Y.-L. Huang, D. W. McOwen and E. D. Wachsman, ACS Appl. Energy Mater., 1, 1559 (2018). Y. Chen, B. deGlee, Y. Tang, Z. Wang, B. Zhao, Y. Wei, L. Zhang, S. Yoo, K. Pei, J. H. Kim, Y. Ding, P. Hu, F. F. Tao and M. Liu, Nat. Energy, 3, 1042 (2018). L. Yang, S. Wang, K. Blinn, M. Liu, Z. Liu, Z. Cheng and M. Liu, Science, 326, 126 (2009).