In situ assembled cobalt free PSFNRu nanocomposites as bi functional electrodes for direct ammonia symmetric solid oxide fuel cells

Symmetric solid oxide fuel cells (SSOFCs) have emerged as promising energy conversion devices due to their low fabrication cost and outstanding durability. Ammonia (NH₃), a carbon‑free hydrogen carrier with high energy density and ease of storage, serves as an ideal fuel for such systems. In this study, a bifunctional electrode material, Pr_0.32Sr_0.48Fe_0.75Ni_0.2Ru_0.05O_3-δ (PSFNRu), is synthesized by doping 5 mol% Ru into the parent perovskite Pr_0.32Sr_0.48Fe_0.8Ni_0.2O_3-δ (PSFN). The resulting PSFNRu exhibits abundant oxygen vacancies and enables the in‑situ exsolution of alloy nanoparticles (ANPs) under reducing conditions, which act as additional active sites to enhance electrochemical performance. The PSFNRu‑based SSOFC delivers peak power densities of 736 mW cm^-2 with H₂ and 547 mW cm^-2 with NH₃ at 800 ℃, significantly outperforming its undoped counterpart. Furthermore, the cell maintains stable performance for over 172 h at 700  ℃ under NH₃ fuel, confirming excellent operational durability. These findings underscore the potential of PSFNRu as a high‑performance symmetric electrode for direct ammonia SSOFCs (DA‑SSOFCs).

Recently, a research team led by Professor Chao Su from Jiangsu University of Science and Technology, in collaboration with Nanjing Tech University and the Beijing Academy of Science and Technology and other institutions, has successfully developed a novel cobalt-free bifunctional electrode material—PSFNRu nanocomposites, which has been applied for the first time in DA-SSOFCs

The findings have been accepted and published online by the journal Nano Research on May 13.

The significance of this research lies in its potential to address critical challenges in clean energy conversion. Solid oxide fuel cells (SOFCs) are known for their high efficiency and low environmental impact. However, their performance has been limited by the low catalytic activity and poor durability of conventional electrode materials when operating with ammonia, a hydrogen-rich and carbon free fuel. The newly developed PSFNRu nanocomposite, created by doping 5 mol% Ru into a traditional perovskite-based material (PSFN), significantly enhances catalytic activity in key reactions, said Shanshan Jiang, lecturer at the School of Energy and Power Engineering, Jiangsu University of Science and Technology and one of the lead authors of the paper.

Experimental results demonstrated that PSFNRu electrodes can in-situ exsolve FeNiRu alloy nanoparticles under reducing atmosphere. These nanoparticles increase the number of active sites and accelerate electrochemical reactions, including the oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), and ammonia decomposition reaction (NDR). When tested in a symmetrical fuel cell configuration at 800 °C, the PSFNRu‑based cell achieved a peak power density of 547 mW cm^-2 using ammonia as fuel, and maintained excellent stability over 172 h with minimal voltage degradation.

Zhixian Liang, the first author of the paper, emphasized that this work marks a critical advancement in the development of DA‑SSOFCs technology. By combining elemental doping with in‑situ exsolution of nanoparticles, the team successfully engineered a high‑performance, durable, and cobalt‑free symmetric electrode material suitable for ammonia‑fueled solid oxide fuel cell operation. Compared with conventional nickel‑based electrodes, the PSFNRu nanocomposite not only avoids severe nanoparticle agglomeration at lower temperatures but also eliminates the need for cobalt. This approach enhances overall performance while significantly reducing material costs, offering improved resource sustainability.

The research team hopes that this material will help advance the development of direct ammonia SOFCs (DA‑SOFCs) and accelerate their path toward commercialization. “This achievement holds significant technical value and provides strategic guidance for the future of clean energy conversion, further reinforcing the feasibility of ammonia as a sustainable fuel.” said Chao Su.

Moving forward, the research team plans to scale up the production of PSFNRu materials and integrate them into larger DA‑SSOFC stacks. They are also exploring compatibility with different electrolyte materials and evaluating the cells in real world operational environments. The ultimate goal is to accelerate the commercialization of ammonia‑fueled SOFCs, particularly for distributed power generation, maritime transport, and off‑grid applications. Potential applications of this technology extend to hydrogen infrastructure as well. Because ammonia is easier to store and transport than hydrogen, DA‑SOFCs offer a practical and energy efficient pathway for clean power generation in regions lacking hydrogen distribution networks.

Other contributors to the study include Zihao Xie from the School of Energy and Power Engineering at Jiangsu University of Science and Technology; Yongning Yi and Wei Wang from the College of Chemical Engineering at Nanjing Tech University; Jingjing Jiang from the Beijing Academy of Science and Technology; Huangang Shi from the School of Environmental Engineering at Nanjing Institute of Technology; and Lei Ge from the School of Engineering at the University of Southern Queensland.

This work is granted by the National Natural Science Foundation of China (Nos. 22309067 and 22279057) and Financial Program of BJAST (Grant No. 25CA002).

About the Authors

First author biography

Zhixian Liang is a graduate student at the School of Energy and Power Engineering, Jiangsu University of Science and Technology, China. His research focuses on the development of electrode materials for SOFCs, including anode materials for DA‑SOFCs and cathode materials for protonic ceramic fuel cells (PCFC). To date, he has published five research articles as first author or co‑author in journals such as Nano Res., Ceram. Int., Int. J. Hydrogen Energy.

Corresponding author biography

Shanshan Jiang, Jiangsu University of Science and Technology. She has been engaged in research on the field of solid oxide fuel cells. As first/corresponding author, she has published over 30+ SCI papers in internationally renowned journal such as Nano Research, Journal of Materials Chemistry A, ChemSusChem, Journal of Power Sources, and International Journal of Hydrogen Energy, covering topics like material design, electrochemical performance optimization, and device applications. Includes 1 ESI Highly Cited Paper and 2 authorized invention patents. She has also participated in several scientific research projects funded by the National Natural Science Foundation of China, the Ministry of Industry and Information Technology, and the Natural Science Foundation of Jiangsu Province.

Jingjing Jiang, Beijing Academy of Science and Technology, Institute of Analytical Testing. Her research primarily focuses on the synthesis, characterization, and catalytic performance of metal-organic frameworks (MOFs) and their derived inorganic nanomaterials, including single-atom materials. Starting from the morphology, composition, and pore structure of MOFs and their derivatives, she designs and develops novel inorganic materials while investigating their formation mechanisms. Her work also explores the structure-activity relationships of nanomaterials and single-atom materials in various applications, including CO₂ adsorption and storage, electrochemical CO₂ reduction, water electrolysis, and fuel cells. She has published over 30 high-impact papers in prestigious international journals such as J. Am. Chem. Soc., PNAS, Small, Nano Research, Acta Physico-Chimica Sinica, Nanoscale, Crystal Growth & Design, and Chinese Journal of Chemistry. She has led four national and provincial-level research projects and participated in three others, in addition to holding one authorized patent.

Chao Su is a Distinguished Professor of Jiangsu Province and was listed among the world’s top 2% scientists by Stanford University in 2022. She received the Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) in 2018 and was a recipient of the Young Scientist Award at the 19th International Conference on Solid State Ionics in 2013. Her research interests include solid oxide fuel cells, advanced low‑temperature electrochemical catalysis, and zinc‑air batteries. To date, she has published over 80 papers in internationally renowned journals such as Chemical Society Reviews, Advanced Energy Materials, and Chemical Engineering Journal, including 8 highly cited papers. Her work has been cited more than 4,400 times with an h‑index of 34. She has led and participated in numerous national and provincial research projects and holds 3 authorized invention patents. She currently serves as a guest editor for Asia‑Pacific Journal of Chemical Engineering and Catalysts.

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.