Like a person breaking up a cat fight, the role of catalysts in a chemical reaction is to hurry up the process – and come out of it intact. And, just as not every house in a neighborhood has someone willing to intervene in such a battle, not every part of a catalyst participates in the reaction. But what if one could convince the unengaged parts of a catalyst to get involved? Chemical reactions could occur faster or more efficiently.
Stanford University material scientists led by Jennifer Dionne have done just that by using light and advanced fabrication and characterization techniques to endow catalysts with new abilities.
In a proof-of-concept experiment, rods of palladium that were approximately 1/200th the width of a human hair served as catalysts. The researchers placed these nanorods above gold nanobars that focused and “sculpted” the light around the catalyst. This sculpted light changed the regions on the nanorods where chemical reactions – which release hydrogen – took place. This work, published Jan. 14 in Science, could be an early step toward more efficient catalysts, new forms of catalytic transformations and potentially even catalysts capable of sustaining more than one reaction at once.
“This research is an important step in realizing catalysts that are optimized from the atomic-scale to the reactor-scale,” said Dionne, associate professor of materials science and engineering who is senior author of the paper. “The aim is to understand how, with the appropriate shape and composition, we can maximize the reactive area of the catalyst and control which reactions are occurring.”
This study's co-authors include Katherine Sytwu, a 2014 EDGE fellow, and Fariah Hayee, a 2018 DARE Fellow.