Tandem Catalysis in Nanocrystal Interfaces
Materials Sciences Division researchers Peidong Yang and Gabor Somorjai have designed layered nanocrystals that allow multiple, sequential catalytic reactions to be carried out selectively and in tandem. This achievement holds intriguing possibilities for industrial catalysis and promising green energy technologies such as artificial photosynthesis.
Catalysts are chemical triggers for manufacturing processes ranging from petroleum refining to making margarine, and are used to speed up rates of chemical reactions. Transition metals in particular are workhorse catalysts, but in recent years, nanoscale metal and metal oxide catalysts have surged in importance as their interfaces can be optimized for specific applications.
Yang and his team introduced tandem catalysis through a multiple interface design, in which alternating layers of platinum and cerium oxide nanocubes are deposited on a silicon dioxide substrate. These layers are each less than 10 nanometers thick and stacked to create two distinct metal--metal oxide interfaces – platinum-silicon dioxide and cerium oxide-platinum.
This technique is valuable for applications in which multiple sequential reactions are required to produce chemicals in a highly active and selective manner, such as artificial photosynthesis---the effort to capture energy from the sun and transform it into electricity or chemical fuels.