IIT-Guwahati Researchers Create Affordable Catalyst to Split Water for Hydrogen

Researchers at the Indian Institute of Technology-Guwahati have developed a nickel-based catalyst that shows strong performance in producing hydrogen from water, offering a potential lower-cost alternative to catalysts based on expensive noble metals.

The catalyst, a three-dimensional coordination polymer called 3D-CPM-a, combines nickel nitrate with a tetraalkynylated anthracene framework. In laboratory tests, it required an overpotential of just 94 ± 14 millivolts at a current density of 100 mA/cm² for the hydrogen evolution reaction at 90°C. By comparison, nickel nitrate alone required 202 mV and the anthracene material 412 mV under the same conditions.

The catalyst also recorded a Faradaic efficiency of about 88%, meaning most of the electrons supplied to the reaction contributed to hydrogen formation. It had an electrochemically active surface area of about 2,300 cm², supporting its high catalytic activity.

Durability is another important result. After 15 hours of operation at 100 mA/cm² and 90°C, the catalyst maintained an overpotential of about 89 mV, indicating good electrochemical stability during the test period. However, this remains a laboratory-scale durability result and does not establish years-long industrial operating life.

The use of nickel, which is substantially less costly and more abundant than platinum and other noble metals, could reduce catalyst-material expenses. However, the researchers have not reported a commercial production cost for the catalyst or a resulting cost per kilogram of hydrogen. Therefore, it is too early to conclude that the technology will make green hydrogen cheaper at an industrial scale.

The catalyst was synthesised at room temperature using ultrasonic treatment, a relatively simple process. The findings were published in the Journal of Materials Chemistry A and could contribute to the development of non-noble-metal electrolyzers for India's green hydrogen ambitions.