Scientists develop new catalyst to help store solar energy

American and Chinese scientists have synthesized a new, dual-atom catalyst to serve as a platform for artificial photosynthesis, a move that may help harvest and store solar energy more efficiently.


In a study reported on Monday in the Proceedings of the National Academy of Science, scientists displayed an iridium catalyst with only two active metal centers, which can directly harvest solar energy and store the energy in chemical bonds, similar to how photosynthesis is performed but with higher efficiencies and lower cost.

Dunwei Wang, Boston College Associate Professor of Chemistry and the paper's lead author, said, "It addresses the critical challenge that solar energy is intermittent," using the "atomically dispersed catalyst" featuring two atoms.

Researchers synthesized an iridium dinuclear heterogeneous catalyst in a facile photochemical way. They reported that the catalyst showed outstanding stability and high activity toward water oxidation, an essential process in natural and artificial photosynthesis.

According to researchers, challenges are that most active heterogeneous catalysts are often poorly defined in their atomic structures, which makes it difficult to evaluate the detailed mechanisms at the molecular level.

Heterogeneous catalysts, widely used in large-scale industrial chemical transformations, involve the form of catalysis where the phase of the catalyst differs from that of the reactants.

Wang said they managed to determine the smallest active and most durable heterogeneous catalyst unit for water oxidation, previously known only to be done for homogeneous catalysts, whose durability was poor.

They also performed X-ray experiments to determine the structure of the iridium catalyst at Lawrence Berkeley National Laboratory.

Wang said the team was surprised by the simplicity and durability of the catalyst, combined with the high activity toward the desired reaction of water oxidation.

Scientists from the University of California, Irvin; Yale, Tufts, and China's Tsinghua and Nanjing Universities also participated the research.
 (chinamedia)
 6/3/18