A procedure is described for preparing a novel model early transition metal oxide system for catalysis studies-direct sublimation of tungsten trioxide on TiO2(110). Isolated monodispersed cyclic trimers, i.e., (WO3)(3), can be formed on TiO2(110) that are thermally stable up to at least 750 K. Although not readily generalizable to monodispersed (WO3)(x) clusters other than cyclic trimers, this protocol provides an ideal nanocluster platform for carrying out model system catalysis studies over a wide temperature range. (c) 2006 Elsevier B.V. All rights reserved.