A bifunctional cathode enabling efficient decomposition and utilization of nitrous oxide in protonic ceramic fuel cells for power generation
image: N2O is decomposed into N2 and O2 catalyzed by the cathode Pr2Ni0.6Co0.4O4-δ composed of Pr4Ni1.8Co1.2O10-δ and Pr6O11. H2 is oxidized into H+ at the anode, and H+ pass through the electrolyte to the cathode where H+ react with oxygen to generate water and generate electricity. It has excellent electrochemical performance, with an exceptional peak power density of 949 mW•cm2 at 650oC.
Credit: Nano Research, Tsinghua University Press
In the context of “dual carbon” goals of China, fuel cells offer a promising solution of utilizing hydrogen energy from intermittent renewable sources, which are considered as compelling energy conversion technologies. Among which, protonic ceramic fuel cells (PCFCs) have been recognized as an alternative technology of providing efficient and clean electric power by using hydrogen energy with high conversion efficiency. Some high-quality and sustainable hydrogen carriers are considered, such as H2, NH3, and CH4, which can be directly utilized at elevated temperatures. Compared to oxygen-ion conducting solid oxide fuel cells (SOFCs), PCFCs are allowed to operate at a relatively lower temperature (≤650oC) owing to excellent conductivity and lower activation energy for proton transport across the electrolytes. The reduction of operation temperature can mitigate many problems such as the cost of materials, fast degradation of cell performance, and so forth. Traditionally, dry air (with oxygen as the oxidant) is fed into fuel cell cathode chambers. However, recent research has explored oxygen-containing gases like nitrous oxide (N2O) as alternative oxidants, expanding PCFC application scenarios while advancing dual-carbon environmental goals.
A team led by Associate Professor Yihang Li and Professor Weiwei Wu from Xidian University recently developed an efficient bifunctional catalyst with the nominal composition of Pr2Ni0.6Co0.4O4-δ (PNCO-214), which is self-transformed into a hybrid of Ruddlesden-Popper (R-P) structured Pr4Ni1.8Co1.2O10-δ (PNCO-4310) and Fluorite structured Pr6O11 (PO-611). The hybrid catalyst is served as the cathode for simultaneous N2O decomposition reaction (NDR) and oxygen reduction reaction (ORR) in PCFCs, achieving a N2O conversion exceeding 90% and area specific resistance (ASR) of 1.301 Ω•cm2 at 600oC. Quasi-in-situ infrared spectroscopy and electrochemical impedance spectroscopy analyses revealed that enriched oxygen vacancies in PNCO-214 facilitated the rapid adsorption and dissociation of N2O into N2 and O2, while boosting the surface exchange kinetics of protons and oxygen during ORR.
When using H2 as fuel and N2O as the oxidant, the assembled single cell for PCFCs further delivered an exceptional peak power density (PPD) of 801 mW•cm2 and total resistance of 0.245 Ω•cm2 at 600oC. Even at a reduced operating temperature of 500oC, the cell maintained excellent performance. Notably, it exhibited robust stability, operating continuously for over 130 hours at 600oC and 0.7V.
This work confirmed PNCO-214’s potential as a high-efficiency cathode catalyst and validated the feasibility of N2O as an oxidant for PCFC operations, paving the way for its application in specific industrial settings. The findings marked a significant step forward in expanding the utility of PCFCs, advancing global carbon reduction efforts.
The team published their article in Nano Research on December 23, 2025.
This work was financially supported by the National Key R&D Program of China (2024YFF0506300), National Natural Science Foundation of China (52336009), Key Research and Development Program of Shaanxi (2024CY2-GJHX-66), Guangdong Basic and Applied Basic Research Foundation (No. 2023A1515010429), Natural Science Basic Research Plan in Shaanxi Province of China (2024JC-YBQN-0475), Xidian University Specially Funded Project for Interdisciplinary Exploration (TZJH2024063), the Fundamental Research Funds for the Central Universities (QTZX23061) and the Innovation Center of Nuclear Power Technology (No. HDLCXZX-2022-ZH-013).
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.