Metal clusters and nanoparticles assembled in zeolites: an example of stable materials with controllable particle size

An ion-exchangeable zeolite (mordenite) is used to control the formation of nanoparticles and clusters within the solid matrix by the hydrogen reduction of metal ions (Ag+, Cu2+, and Ni2+). SiO2/Al2O3 molar ratio in mordenite appears to be an efficient tool to manage the reducibility of the metal ions. Few-atomic silver clusters in line with the larger silver nanoparticles were observed with DRS for the reduced Ag+-exchanged mordenites. Cu2+-exchanged ones produce the copper nanoparticles with different optical appearance, and Ni2+-exchanged mordenites are reduced up to complicated species with no explicit assignment of metal particles under the conditions studied. (C) 2002 Elsevier Science B.V. All rights reserved.