Multitechnique investigation of the physisorption and thermal treatment of mixed-metal clusters on carbon

Christopher Willocq; Arnaud Delcorte; Sophie Hermans; Patrick Bertrand; Michel Devillers

doi:10.1021/jp050560q

Multitechnique investigation of the physisorption and thermal treatment of mixed-metal clusters on carbon

J Phys Chem B. 2005 May 19;109(19):9482-9. doi: 10.1021/jp050560q.

Authors

Christopher Willocq¹, Arnaud Delcorte, Sophie Hermans, Patrick Bertrand, Michel Devillers

Affiliation

¹ Unité de Chimie des Matériaux Inorganiques et Organiques, Université Catholique de Louvain, Place Louis Pasteur 1/3, B-1348 Louvain-la-Neuve, Belgium.

PMID: 16852139
DOI: 10.1021/jp050560q

Abstract

The three clusters [Ru6PtC(CO)16(COD)] (1), [Ru5PtC(CO)14(COD)] (2) (COD = 1,5-cyclooctadiene), and (NEt4)2[Pd6Ru6(CO)24] (3) were physisorbed onto an active carbon support and used as molecular precursors for supported particles. The samples before and after thermal treatment at 300 degrees C were characterized by a combination of SIMS, XPS, SEM and XRD. It was found that the clusters are molecularly intact, but present in the form of agglomerates on the support at the end of the physisorption step. After thermal treatment, the ligands were lost in all cases, leaving on the surface bimetallic particles containing both starting metals (Ru-Pt in the case of 1 and 2, and Ru-Pd in the case of 3). The presence of the counterion was evidenced for 3, before, but not after, heating. Molecular clusters are thus interesting precursors for the preparation of supported bimetallic phases, and SIMS is the ideal technique to characterize them at each step of their preparation.