Researchers are uncovering innovative methods to enhance the hydrogen evolution reaction, making it more effective and efficient.
Optimizing the processes that generate hydrogen (H2) as a clean energy source is vital in the battle against climate change. A team from Tohoku University and the Tokyo University of Science has made strides in boosting the catalytic efficiency of this reaction. They developed a synthesis technique that enables control over the surface architecture of tiny metal particles measuring around 1 nanometer in diameter.
The findings were published in the Journal of the American Chemical Society on October 25, 2024.
Hydrogen serves as an eco-friendly substitute for traditional energy sources like fossil fuels. One popular method to derive hydrogen from water is through the hydrogen evolution reaction (HER), which uses electric current and typically requires an electrocatalyst to reduce the activation energy, thus making the process more efficient. However, a major drawback is that it often necessitates expensive rare metals such as platinum.
To make hydrogen fuels a more affordable and feasible option, researchers explored the use of less costly metals. They engineered a metal nanocluster (NC) that combines gold (Au) and platinum (Pt) for this purpose. Since gold is significantly more abundant and cheaper than platinum, this combination helps to decrease hydrogen production costs.
This study focused on AuPt nanoclusters (NCs) featuring two innovative geometrical and electronic configurations. “In comparison to traditional AuPt NCs, these new structures had smaller ligands, which was expected to enhance access to the active site and boost catalytic efficiency,” explains Professor Yuichi Negishi from Tohoku University. “We have been investigating ways to enhance these reactions for some time, and our previous work indicated that the length of the ligand significantly influences HER performance.”
Upon evaluating their newly synthesized AuPt NCs, the researchers found that these new catalysts exhibited 3.5 to 4.9 times greater catalytic activity for the HER than conventional AuPt alloy catalysts.
This research has unveiled a technique to accurately manage the surface structure of ultra-fine metal aggregates. It may also open doors for alternative catalytic uses, including carbon dioxide reduction, carbon monoxide oxidation, alcohol oxidation, and oxygen reduction reactions. This breakthrough could lead to the development of novel functional materials, bringing us closer to a future powered by clean hydrogen rather than gasoline.
