Researchers at the Indian Institute of Technology (IIT) Madras have developed an indigenous and cost-effective alkaline seawater electrolyser capable of producing green hydrogen without the use of rare and expensive metals. The innovation could help reduce dependence on fossil fuels while addressing the challenge of freshwater scarcity in large-scale hydrogen production, reports Hans India.
Conventional electrolysers rely on costly noble metals like ruthenium and iridium and use large volumes of freshwater. Since nine litres of water are needed to produce one kilogram of green hydrogen, India would require around 50 billion litres of fresh water annually to meet its target of producing five million tonnes. The new technology instead uses alkaline seawater and affordable transition metal-based catalysts that resist corrosion and efficiently produce both hydrogen and oxygen.
Explaining the breakthrough, Professor S. Ramaprabhu of the Physics Department at IIT Madras said the electrolyser uses bimetal catalysts that are more effective in promoting oxygen evolution reactions while suppressing the unwanted formation of hypochlorite when seawater is used. “By replacing freshwater with alkaline seawater and employing cost-effective catalysts, we can make hydrogen production both affordable and sustainable,” he said.
The team has successfully scaled up the technology from a single cell to a nine-cell stack, capable of producing up to 50 litres of hydrogen per hour when powered by commercial solar photovoltaic systems.
India has set an ambitious goal under the Ministry of New and Renewable Energy to become a global hub for green hydrogen by 2030. According to Prof. Ramaprabhu, widespread adoption of indigenous hydrogen production technologies will have multiple benefits. “Green hydrogen can power fuel-cell vehicles, provide clean energy, and be used in industries like steel, chemicals, and fertilisers. Producing green ammonia from hydrogen will cut reliance on fossil fuels and significantly lower carbon emissions,” he noted.
