New guidelines laid down by Nebraska and Chinese researchers could steer the design of less costly, more effcient catalysts geared toward revving up the production of hydrogen as a renewable fuel.
Nebraska’s Xiao Cheng Zeng and colleagues have identified several overlooked factors critical to the performance of single-atom catalysts: individual atoms, usually metallic and anchored by surrounding molecular frameworks, that kick-start and accelerate chemical reactions.
The team folded those variables into a simple equation requiring what Zeng described as “back-of-the-envelope calculations.” That equation should allow researchers to easily predict how the choice of an atom and its surrounding material will affect catalytic performance. To date, researchers have often relied on time-consuming trial and error to find promising single-atom catalysts.
“All this (relevant) information can be easily gathered from a textbook,” said Zeng, Chancellor’s University Professor of chemistry. “Even before an experiment, you can quickly see whether it’s a good way to make the catalyst. We’re simplifying the process.”
Using its equation, the team discovered several atom-framework combinations that approximate the performance of precious-metal catalysts—platinum, gold, iridium—at mere thousandths of the cost. One swapped out a platinum atom for manganese; another replaced iridium with cobalt.
“There are two (primary) ways to reduce the price of these catalysts,” Zeng said. “One is to use as little of the metals as possible—so single-atom catalysts are the cheapest. The other direction is finding alternative metals like iron or aluminum or zinc that are very cheap.”
thumbnail courtesy of phys.org