IIT-Guwahati develops low-cost nickel catalyst to make hydrogen from water

Researchers at the Indian Institute of Technology-Guwahati have developed a low-cost catalyst to produce hydrogen from water, a step that can support the country’s National Green Hydrogen Mission and accelerate the shift to sustainable energy sources, according to a statement.

Hydrogen is considered an important part of the global move to clean energy because, when used to produce energy, it generates only water as a byproduct, unlike petroleum-based fuels that release pollutants. It is also used in fuel cells and serves as a raw material in several industrial processes, including the production of fertilisers.

At present, 90-95 per cent of hydrogen is produced from fossil fuels. ‘Grey’ and ‘blue’ hydrogen are produced from natural gas, while ‘brown’ and ‘black’ hydrogen are produced from coal. The production of these forms of hydrogen releases greenhouse gases, which negates the environmental benefits of using hydrogen.

The statement said water is the cleanest source of hydrogen, but producing hydrogen from water through electrolysis requires efficient catalysts. Researchers around the world are studying different materials for this purpose, but the most effective catalysts now available are made from rare and expensive noble metals, limiting their large-scale use.

To address this, the IIT-Guwahati team used a nickel salt, which is inexpensive and widely available, as one of the components of the water-splitting catalyst. Since nickel salt alone is not efficient enough for hydrogen production and lacks stability, the researchers combined it with an anthracene-based organic molecule.

Explaining the work, Akshai Kumar, associate professor in the Department of Chemistry at IIT-Guwahati and the lead researcher, said, "We synthesised the coordination polymer (CP) based catalyst where the anthracene units are interlinked via the nickel nodes in a simple process at room temperature, aided by ultrasonic waves." He added, "In these materials, metal atoms are connected by organic molecules, forming an extended network. The structure provides a high density of active sites for the hydrogen evolution reaction and allows for efficient electron transport through the material."

The findings have been published in the ‘Journal of Materials Chemistry A’ in a paper co-authored by Kumar in collaboration with Kalishankar Bhattacharyya, assistant professor in the Department of Chemistry, and research scholars Niharika Tanwar, Jumana Ishrat and Khadimul Islam, all from IIT-Guwahati.

Providing theoretical insights into the work, Bhattacharyya said, "The results reveal a significant synergic effect in the combination of nickel and the anthracene-based framework, with each component enhancing the performance of the other." The catalyst was also found to be stable during long-term operation.

The researchers found that nearly 88 per cent of the electrical energy was used to split water, with low wastage seen as essential for developing practical systems for large-scale hydrogen production. The team also carried out chemical analysis and modelling studies to understand why the catalyst performed well, and found that the nickel atoms formed a three-dimensional network with the anthracene moiety, the statement added.

The study, according to the statement, presents a low-cost approach to hydrogen production from water by combining nickel salt with an anthracene-based framework, while also showing stability in long-term operation and efficient use of electrical energy.