Corrosion-proof catalyst powers seawater electrolysis 

Oceans have long inspired humanity with their vastness and power. Beyond this beauty lies an untapped potential: seawater as a source of clean, renewable energy. In theory, electrolysis can be used to split seawater into oxygen and hydrogen, providing a sustainable alternative to fossil fuels and a means of energy storage, while also preserving pure water for other pressing needs.  

Harnessing this resource, however, is far from simple. The corrosive nature of seawater—a dilute solution of salts, including sodium chloride—reduces the efficiency of most catalysts that work well with pure water. The chemical reactions that produce oxygen from water and chlorine from chloride ions compete for active sites on the catalyst, reducing its efficiency, and hence hydrogen production.  

Even worse, once formed, chlorine eats away at the catalyst, creating pits and cracks that ruin its surface, reducing the number of active sites. This corrosion has long stood in the way of scaling up seawater electrolysis. 

“Anti-corrosive anodes are crucial for efficient seawater electrolysis. This newly developed material represents a significant advancement and shows great promise for such reactions.” 

Ahsan Ul Haq Qurashi

Now, researchers at Khalifa University have engineered a material capable of withstanding saline’s corrosive effects while speeding up splitting water into hydrogen and oxygen. 

At first glance, the cerium-doped strontium cobalt oxide (Ce-SrCoO_x) looks like an ordinary fine powder, no different from many others in a laboratory. But closer inspection reveals an intricate design that allows it to survive the harshest conditions. 

Introducing cerium, a rare-earth metal, into strontium cobalt oxide transforms the material at both the surface and structural levels. On the surface, some of the cerium oxidizes, forming a layer that acts as a shield, blocking corrosive chlorine while still allowing water molecules to reach the catalyst. Beneath this protective layer, the cerium alters the atomic structure of the material, creating tiny, controlled defects—microscopic holes in the crystal structure where water molecules can break apart more efficiently. 

In simulated seawater, the Ce-SrCoO_x catalyst showed outstanding resistance to corrosion and exceptional efficiency in producing oxygen, indicating its effectiveness in water splitting—key for hydrogen production. Even after 45 hours of continuous use, the material maintained its performance with minimal wear. Further tests with local seawater from the United Arab Emirates, which is rich in impurities, proved the catalyst’s durability, signaling a step towards practical, large-scale seawater electrolysis. 

“Anti-corrosive anodes are crucial for efficient seawater electrolysis. This newly developed material represents a significant advancement and shows great promise,” says Ahsan Qurashi, who led the research at KU. 

Reference

Uddin, M.M., Pirzada, B.M., Rasool, F., Anjum, D., Price, G. & Qurashi, A. Surficial reconstruction in bimetallic oxide SrCoOx through Ce-doping for improved corrosion resistance during electrocatalytic oxygen evolution reaction in simulated alkaline saline water. Nano Res. Energy, 4 (e9120162), 2025. | Article