NEWS
Norman, Okla. – Hydrogen fuel holds significant promise for clean energy. It burns without producing carbon emissions and it can store energy from wind and solar power for later use. But building the devices that make and use clean hydrogen reliably is a challenge. A University of Oklahoma researcher has published two high-impact studies that take on that challenge and make progress on a problem that has slowed the technology for years.
Hanping Ding, a professor in the Gallogly College of Engineering, led both studies, which focus on protonic ceramic cells, or PCCs, and the same weak point within them. PCCs are an emerging clean energy technology capable of working in two modes: converting water into hydrogen fuel or generating electricity from hydrogen. This two-way capability makes them useful for storing energy from solar and wind. However, the oxygen electrode in a PCC degrades over time due to exposure to high heat and steam.
“We’re demonstrating that redesigning and controlling the interface engineering is not a minor factor,” Ding said. “It is a dominant factor that can determine the future commercialization of this technology.”
Angewandte Chemie International Edition
The study published in Angewandte Chemie International Edition introduces a new way to design the electrode structure itself so that it holds up better over time. The electrode is built on a sponge-like structured triple conducting perovskite material that lets gases and charged particles move through it easily.
“We also discovered a new mechanism — what we call vacancy–redox coupling — that plays a critical role in stabilizing the system during operation,” said Ding.
Through this breakthrough, missing oxygen atoms (“vacancies”) and changes in metal atom charge (“redox”) are tightly linked at the material’s interface. This lets the material continuously adjust its structure and defects as it operates.
In lab tests, the results were strong. The new electrode delivers high power output and efficient hydrogen production. It also kept a high Faradaic efficiency (over 92%), meaning most of the electrical energy was effectively converted into useful chemical products. Under harsh, steam-rich conditions, the new electrode showed minimal signs of degradation over more than 200 hours of operation.
Advanced Energy Materials
The second study, published in Advanced Energy Materials, focuses on a different weakness of the oxygen electrode: the seam between the oxygen electrode and the layer beneath it, the electrolyte.
In most devices today, the electrode and the electrolyte are pressed together. They touch at scattered points, like two pieces of gravel pushed against each other, so the current flows between a handful of spots rather than spreading evenly. Those spots overheat, wear out faster and eventually cause the device to fail.
“What excited me most about this work is that we addressed one of the most critical bottlenecks in protonic ceramic cells—the interface itself, which often controls both performance and long-term durability. By engineering an interlayer, we were able to strengthen the electrode–electrolyte connection and achieve stable reversible operation under steam-rich conditions,” said Shuanglin Zheng, a graduate student and lead author on both publications.
Ding’s team used a technique called pulsed laser deposition — a process developed by OU researcher Thirumalai Venkatesan — to add an ultra-thin layer of material at the seam before the electrode goes on, filling in the gaps and creating a smooth, continuous connection across the surface. With that change, the bond between the electrode and electrolyte became about three times stronger, making it far more resistant to the stress of repeated heating and cooling. Power output increased, and in hydrogen production mode, the device ran for roughly 1,000 hours under pressurized steam while maintaining efficiency above 92 percent.
Together, the studies establish a new design approach for advanced energy materials. The breakthroughs provide a strong foundation for the practical commercialization of PCCs and related hydrogen technologies for clean hydrogen production and energy conversion.
About the research
“Vacancy–Redox Coupling at Interface-Engineered Heterostructures Enhances Reversible Energy Conversion in Protonic Ceramic Cells” is published in Angewandte Chemie International Edition at doi.org/10.1002/anie.7079252. Researchers from the University of Utah and Curtin University (Australia) were also part of the work.
“Interfacial Nanostructuring Enables Integrated, Low-Polarization Reversible Protonic Ceramic Cells” is published in Advanced Energy Materials at doi.org/10.1002/aenm.70850.
About the University of Oklahoma
Founded in 1890, the University of Oklahoma is a public research university located in Norman, Oklahoma. As the state’s flagship university, OU serves the educational, cultural, economic and health care needs of the state, region and nation. For more information about the university, visit www.ou.edu.
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