Making uncommon nanocatalyst shapes

Abstract

A simple vapor-phase process converts common metal precursors to unusually shaped, catalytically active metal nanocrystals that are difficult to produce via other methods. The procedure, which was used for making single-metal and bimetallic nanocrystals, may provide a low-cost route to catalysts for fuel cells and other applications (Science 2019, DOI: 10.1126/science.aax5843). The catalytic activity of one face of a crystal may be different from that of other faces, a result of each face’s unique geometry and electronic properties. Thermodynamics favors the most stable faces. But because those may not be the most catalytically active ones, chemists often rely on organic capping ligands to stabilize specific faces and guide crystals to grow in a desired shape. The ligands, however, can block active sites and must be removed, complicating the process and sometimes adversely altering the crystals. Northwestern University’s Liliang Huang, Chad A. Mirkin, and coworkers have come up with a way