Helping catalysts breathe: ICFO Research links bubble release to better water electrolysis
Researchers led by ICFO have shown how engineering a catalyst’s surface can improve water access and help oxygen bubbles detach—offering a promising route towards more efficient hydrogen production.
Walerian Majewski ·
Gas bubbles are an unavoidable part of water electrolysis. But when they accumulate on an electrode, they can obstruct the very reaction that produces them.
At the anode, oxygen bubbles can cover active sites and restrict water access. This becomes particularly challenging under acidic conditions and at high current densities. Researchers led by Professor F. Pelayo García de Arquer at ICFO investigated how changes to the catalyst surface could address both problems together.
The collaboration included ICN2, ICIQ, the University of Bayreuth and ALBA Synchrotron. ICFO highlighted the findings in its 22 October announcement.
The team combined ruthenium oxide with cerium oxide, creating a RuOₓ–CeOₓ catalyst. Their evidence links cerium-assisted surface oxygen vacancies with improved hydration and easier bubble detachment.
Compared with the ruthenium-oxide control, the modified catalyst showed a fourfold reduction in median bubble contact area. This describes the bubbles’ footprint on the surface, not a fourfold reduction in diameter.
The researchers also demonstrated a device-level benefit. At 1 A/cm², their PEM water electrolyser operated at 1.75 V, compared with 1.83 V for the control. A separate durability test showed stable operation for 150 hours at 200 mA/cm² and 80°C. These are laboratory results, rather than evidence of commercial stack lifetime. Scientific paper
For electrolyser developers, the study points towards a useful design principle: catalyst performance depends on how water reaches the surface and how gas leaves it, as well as the reaction itself. Improving those interactions could help reduce energy losses, although the results do not establish a specific reduction in commercial hydrogen costs.
The research was published online on 26 September 2026, ahead of ICFO’s October news release.
Scientific reference
Das, A. M., et al. “Oxygen Management in Ruthenium–Cerium Anode Facilitates Water Adsorption and Bubble Desorption for Oxygen Evolution at High Current Densities.” ACS Catalysis 16 (20), 20038–20051 (2026).
https://doi.org/10.1021/acscatal.6c04063