Peidong Yang and colleagues, Lawrence Berkeley National Laboratory, California, USA, have created bilayered nanocrystals of a metal-metal oxide that can perform multiple, sequential catalytic reactions selectively and in tandem.
The team used the Lamgmuir-Blodgett assembly technique to deposit nanocube monolayers of platinum and cerium oxide onto a silica substrate. The nanocube layers were less than 10 nm thick and were stacked to create two distinct metal–metal oxide interfaces — CeO2–Pt and Pt–SiO2. The cerium oxide-platinum interface catalyzed methanol decomposition to produce CO and H2. These then underwent ethylene hydroformylation at the platinum-silica interface resulting in the production of propanal. This tandem catalysis approach should be relevant to photoelectrochemical reactions, such as solar water splitting or artificial photosynthesis, where sequential, multiple reaction steps are necessary.