Catalysts accelerate chemical reactions, but the widely used metal platinum is scarce and expensive. Researchers at Eindhoven University of Technology (TU/e), together with Chinese, Singaporean and Japanese researchers, have now developed an alternative with a 20x higher activity: a catalyst with hollow nanocages of an alloy of nickel and platinum.

TU/e researcher Emiel Hensen wants to use this new catalyst to develop a refrigerator-size electrolyzer of about 10 megawatts in the future. The results have been published in the journal Science.

By 2050, the Dutch government aims to getalmost all of the national energy requirements from sustainable sources, such as the sun or the wind. Because these energy sources are not available at all times, it is important to be able to store the generated energy. Given their low energy density, batteries are not suitable for storing very large amounts of energy. A better solution is chemical bonds, with hydrogen as the most obvious choice of gas. Using water, an electrolyzer converts (an excess of) electrical energy into hydrogen, which can be stored. At a later stage, a fuel cell does the opposite, converting the stored hydrogen back into electrical energy. Both technologies require a catalyst to drive the process.

The catalyst that helps with these conversions is – due to its high activity – mostly made of platinum. But platinum is very expensive and relatively scarce; a problem if we want to use electrolyzers and fuel cells on a large scale. TU/e catalysis professor, Emiel Hensen: “Fellow researchers from China therefore developed an alloy of platinum and nickel, which reduces costs and increases activity.” An effective catalyst has a high activity; it converts more water molecules into hydrogen every second. Hensen continues: “At TU/e, we investigated the influence of nickel on the key reaction steps and to this end we developed a computer model based on images from an electron microscope. With quantum chemical calculations we were able to predict the activity of the new alloy, and we could understand why this new catalyst is so effective.”

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Source: “Storing energy in hydrogen 20 times more effective using platinum-nickel catalyst”, Eindhoven University of Technology