VATIS UPDATE Article

Scientists at Ames Laboratory, the United States, have discovered a method for making smaller, more efficient intermetallic nanoparticles for fuel cell applications, and which also use less of the expensive pre-cious metal platinum. The researchers succeeded by overcoming some of the technical challenges present-ed in the fabrication of the platinum-zinc nanoparticles with an ordered lattice structure, which function best at the small sizes in which the chemically reactive surface area is highest in proportion to the particle volume.

“That surface-to-volume ratio is important in getting the most out of an intermetallic nanoparticle. The smaller the particle, the more surface there is, and more surface area increases the catalytic activity,” said Wenyu Huang, at Ames Laboratory. But the high temperature of the annealing process necessary to form intermetallic nanoparticles often defeats the goal of achieving a small size. High-temperature annealing can cause the particles to aggregate or clump, and produces larger sizes of particles that have less available surface and aren’t as reactive.