Copper nanoparticles in zeolite Y

CuCl has been dispersed in the supercages of a Y-type zeolite by heating a mechanical salt/host mixture in vacuo. The occluded salt was subsequently r educed to copper metal in a hydrogen atmosphere. Virtually complete reducti on of the salt is achieved at 460 degrees C. Under the same conditions, ext raframework copper(II) ions, exchanged into zeolite NaY, are only partly re duced. The copper forms nanoaggregates of narrow size distribution inside t he zeolite pore system; the average particle diameter is 5 nm. Our data sug gest that these nanoparticles consist of several interconnected copper asse mblies of supercage (diameter 1.2 nm) size. A small fraction of the salt re mains at the outer surface of the zeolite crystallites in the inclusion ste p, and there produces larger copper metal particles upon reduction with H-2 .