Bimetallic clusters supported on mesoporous silica: the effects of support interactions on cluster morphology

Small bimetallic clusters supported on mesoporous silica have proved to be exceptionally active as hydrogenation catalysts [Amer. Philos. Soc. 388 (1999) 143]. Such catalysts are often extremely stable, especially when containing either copper or silver as one of their chemical constituents, forming arrays of strongly anchored discrete clusters [Angew. Chem. Int. Ed. Engl. 36 (1997) 2242, Chem. fur. J. 4 (1998) 1214]. Here, we show, using density functional theory (DFT), how different modes of anchoring can influence the morphology of the supported cluster. Together with extended X-ray absorbtion fine spectra (EXAFS) analysis, these DFT simulations have yielded the most favourable cluster-silica bonding scenario for the Ru12Cu4C2 nanoparticle catalyst. (C) 2001 Elsevier Science B.V. All rights reserved.