Nanoparticles (NPs) are used as catalysts in a range of reactions, from refining chemicals to producing polymers and biofuels. How well nanoparticles catalysts perform depends on which crystal face is exposed. Attempts to control the shape and exposed face of NPs have failed because the structures are unstable and will revert back to their equilibrium shape.

Laurence Marks and co-workers, Northwestern University, Illinois, USA, have found that they can control the shape of Pt NPs by controlling the particle’s support structure. The team used SrTiO₃ nanocuboids as the support which allowed the growth of NPs with a strong cube-on-cube epitaxy. This was shown to be a thermodyamically stable shape which exposed different surfaces of the NPs compared with NPs on polycrystalline supports.

These results demonstrate that epitaxy — the relationship between the position of the atoms in the nanoparticle and the position of the atoms on the substrate — is more important to design than previously thought.

• Oriented Catalytic Platinum Nanoparticles on High Surface Area Strontium Titanate Nanocuboids
  J. A. Enterkin, K. R. Poeppelmeier, L. D. Marks,
  Nano Lett. 2011.
  DOI: 10.1021/nl104263j