Empa’s Proton Highway Project Aims to Boost Green Hydrogen Production

In the latest hydrogen news, a Swiss-led research effort is taking aim at one of the trickiest challenges in green hydrogen production: moving protons rapidly and reliably through solid ceramic membranes. The initiative, informally called the Proton highway, is spearheaded by Empa—the Swiss Federal Laboratories for Materials Science and Technology—and backed by the Swiss National Science Foundation (SNSF) under its External Lead Agency program. By combining crystallographic snapshots with vibrational studies from partners in Switzerland, the U.S., and Japan, the project is mapping the atomic-scale highways and traffic jams that govern proton transport in ceramic electrolytes used in fuel cells and electrolysers. These insights could open new avenues in both hydrogen fuel cell news and clean hydrogen news, driving down costs and boosting performance.

The challenge of proton transport in ceramic membranes

Proton-conducting ceramic membranes lie at the core of protonic ceramic fuel cells (PCFCs) and protonic ceramic electrolysis cells (PCECs). At intermediate temperatures—roughly 300 °C to 600 °C—they offer a sweet spot: higher conductivity than oxide-ion ceramics and more robust operation than polymer membranes. In these systems, hydrogen-containing gases dissociate at the membrane surface, protons incorporate into the oxide lattice, and then hop between adjacent oxygen sites via the Grotthuss mechanism. But despite the promise, few materials combine high proton uptake with fast migration. When a ceramic soaks up too many protons, the added defects can distort its lattice, turning what should be an “expressway” into a rough, narrow path that slows ions to a crawl. That trade-off between capacity and mobility remains a central bottleneck in improving efficiency, reducing degradation, and cutting system costs for advanced hydrogen production methods.

The Proton highway project

Rather than tweaking individual devices, the Proton highway project opts for a more fundamental tack. Dr. Artur Braun and his team in Empa’s Laboratory for High Performance Ceramics bring over two decades of expertise in proton-conducting materials. They’ve noted that conductivity can fluctuate wildly, hinting at a dynamic interplay between protons and lattice vibrations. To tease out the most blocking features, the consortium deliberately studies a weak conductor: lanthanum–cerium oxide (LCO). While LCO can accommodate large numbers of protons, its conductivity is almost nil—like a total gridlock. This extreme example makes the traps and barriers easier to identify, guiding researchers toward structural factors that must be altered or avoided in better materials. The project page, titled “Protonen-Autobahn” in German, signals the team’s intent to pave multi-lane paths for ions rather than single-file tracks. SNSF funding also covers complementary measurements at large-scale U.S. and Japanese neutron and spectroscopy facilities, rounding out the experimental dataset.

Leveraging neutron crystallography at PSI

To get a clear picture of where protons sit in LCO and related ceramics, the team turned to the Paul Scherrer Institute (PSI) in Villigen. There, powerful neutron diffraction instruments reveal hydrogen positions that X-rays often miss. By analyzing how neutrons scatter off the lattice, researchers can map subtle shifts in oxygen octahedra and locate hydroxyl defects across various hydration levels. These high-resolution snapshots form the static foundation of the project, showing exactly where protons bind and how the lattice accommodates them—information that’s essential before you can predict how ions will move. Neutron diffraction experiments are refined with advanced crystallographic software, yielding atomic models that resolve occupancy of even light hydrogen atoms. Those detailed structures feed into computational simulations that screen candidate materials and suggest chemical modifications before synthesis.

Capturing lattice dynamics and phonon–proton coupling

Static structure is only half the story. Inelastic neutron scattering—and complementary vibrational probes at U.S. and Japanese facilities—measures the phonon spectra, showing how atoms vibrate within the lattice. These vibrations momentarily lower migration barriers, giving protons brief windows to hop freely. Braun’s earlier work showed that proton conductivity can surge when lattice distortion flattens energy landscapes—a dynamic effect you’d miss with static snapshots alone. In practice, experiments record energy loss and gain of neutrons as they scatter, revealing vibrational modes tied to specific atomic movements. Researchers correlate these modes with activation energies from conductivity tests, validating theoretical models that tie lattice vibrations to ionic pathways. That way, they can pinpoint which phonon frequencies help or hinder proton hops and adjust material chemistry accordingly.

Implications for PCFC and PCEC technologies

The insights gained could transform the design of electrolytes for fuel cells and electrolysers. Today’s protonic ceramic devices often demand high-temperature sintering, struggle under steam, or react with CO₂—issues that hamper durability and add cost. Armed with new design rules, researchers can tailor perovskite-type oxides—doped barium cerates and zirconates, plus novel lanthanum–cerium-based compositions—to hit the sweet spot between uptake, mobility, and chemical stability. That might mean membranes that achieve higher conductivity at lower temperatures, tolerate industrial gas streams, and integrate more easily into stack manufacturing. Improved membranes shrink system size, boost efficiency, and cut replacement costs in distributed power systems, chemical plants, and emerging hydrogen infrastructure. In PCFCs, water forms on the air side, enhancing fuel utilization; in PCECs, dry hydrogen can be produced at elevated pressure, directly addressing key hydrogen storage methods and compression challenges.

Collaborations and Swiss funding

The Proton highway project showcases Switzerland’s strength in energy-transition R&D. Funded by the SNSF’s External Lead Agency program, it benefits from multi-year support that bridges basic science and applied materials development. Empa leads the scientific coordination, while PSI’s neutron capabilities and international partners’ vibrational labs round out a truly global effort. This structure reflects Switzerland’s long-standing investment in physics and materials science infrastructure, as well as federal strategies to back hydrogen initiatives. The External Lead Agency scheme is designed for collaborative projects where a Swiss institution coordinates international teams, ensuring that comprehensive expertise—from crystal structure analysis to phonon dynamics—is brought to bear on hydrogen challenges.

Broader impact on green hydrogen infrastructure

While the Proton highway project stays firmly in the realm of fundamental research, its ripple effects could reach far beyond the lab. Better ceramic membranes could lower the energy needed per kilogram of green hydrogen, curb indirect greenhouse gas emissions, and unlock more efficient integration with industrial waste heat. That boosts the economic case for large-scale electrolyzers in chemical plants and refineries, while smaller units could power distributed systems or even data centers, aligning with trends in green data centers. Advanced membranes may also find use in hydrogen separation reactors and sensors, diversifying their role in a future hydrogen economy. By clarifying which materials and device architectures hold the most promise, Empa’s team is helping policy makers and investors chart a realistic path to a sustainable hydrogen future.

In an age where every efficiency gain counts, getting protons to race along intentional highways rather than stumble through bottlenecks might be one of the most critical materials challenges left in clean energy. With its blend of neutron crystallography, lattice dynamics, and Swiss-led collaboration, the Proton highway project offers a road map to turning that vision into reality.