Because of their high efficiency, catalysts with only a few atoms hold great promise in the field of water treatment. In a new study, researchers want to improve the performance of these materials (Cleaning water with just a few atoms) and make them more usable.
The results of the study, led by Professor Jaehong Kim, are published in the Proceedings of the National Academy of Sciences.
In recent decades, nanoscale catalysts have attracted great interest in the field of water treatment. Nanoscale devices have many unique and valuable features to offer. Recently, researchers have explored the possibility of single-atom catalysts. Although smaller than nanomaterials, these catalysts can provide greater efficiency.
Kim, Henry P. Becton Sr. Professor of Chemical and Environmental Engineering said, “We didn’t have this ability before, but now we are loading metals atom by atom, atom by atom, onto the substrate. “And that’s good, because you can use whole atoms.”
Efficiency is key because the materials used in manufacturing can be expensive. For example, palladium (currently worth about $2,000 an ounce) is a commonly used metal for metallurgists. A quick comparison shows why single atom catalysts have attracted so much interest. At the nanoscale, 50 nanometers of palladium costs about $37 to cover an area of about 250 square meters. Just over 2% of its atoms are exposed to the surface. In one atomic form, on the other hand, palladium costs only 17 cents to cover an area of more than 50 square feet. And you can’t beat it for efficiency, with 100% atomic surface exposure.
A limitation of single atom catalysts is that certain conditions can reduce their catalytic efficiency. To solve this problem, researchers have now begun to create materials that make people have small groups of atoms, called ensembles. Instead of three thousand components of nanomaterial, these clusters have only three or four. “But they exhibit properties like single atoms because they are small groups, and all atoms are exposed to the surface,” Kim said.
Because this invention is still new, researchers are still looking for the best way to control the characteristics of this assembly structure and improve their performance. For example, an isolated atom can be enhanced by adding certain elements around the metal. Kim and his research team investigated whether atomic structures could be manipulated in the same way. Their article is the first to explore the possibility of doing so.
Kim developed a system with a catalyst that uses many palladium atoms, designed to reduce the carcinogenic bromate in water. They introduced the non-metals sulfur, nitrogen and boron into the tentacles of the atom.
The overall results show an improvement in the catalytic performance of the system. That’s a promising sign, Kim said, especially since water treatment should be as affordable as possible.
“Finally, we hope to have an effective device with a catalyst to destroy water pollutants, because it will be cheaper and more efficient than planned other resources,” he said.
