Catalytic Properties of High-Density Monodispersive Metal Nanostructures

Abstract

We report on ultra-high catalytic activity of high-density monodispersive Cu and Ni nanostructures fabricated by newly developed laser electrodispersion technique. In these structures the particle sizes are 5 nm for Cu and 2.5 nm for Ni (relative size dispersion is less than 20%). Due to fast cooling during particle formation Cu and Ni grains have amorphous structure. The catalytic activity of Cu-based structures were studied in chlorohydrocarbons transformations reactions, while Ni structures were tested in the reaction of 1-nonene hydrogenation. The measured catalytic activity vs. particle surface density dependencies exhibit a maximum corresponding to densely packed one-layer granulated films. About an order of magnitude increase in the catalytic activity is observed when increasing the dielectric permittivity of the reactant solution. It is suggested that the observed high catalytic activity is due to thermally activated interparticle electron tunneling, which results in the appearance of negatively and positively charged particles in densely packed granulated films.