title: Molybdena deposited on titania by equilibrium deposition filtration: structural evolution of oxo-molybdenum(vi) sites with temperature.
abstract: The equilibrium deposition filtration (EDF) method, an advanced catalyst synthesis route that is based on a molecular level approach, can be used for tailoring the oxometallic phase deposited on a porous oxide support. Here, the EDF method is used for synthesizing (MoOx)n/TiO2 catalysts. In situ Raman spectroscopy in the temperature range of 25-450 °C, low temperature (77 K) EPR spectroscopy and DR-UV spectroscopy are used for studying the evolution of the structural configuration of oxo-Mo(VI) species on TiO2 with increasing temperature as well as the influence of the supported (MoOx)n species on the photo-generation of electrons and holes of TiO2. This study concerns (MoOx)n/TiO2 samples in which the surface densities after calcination are 0.3, 2.6 and 3.9 Mo per nm(2), thereby covering a very wide range of submonolayer coverage. The gradual heat treatment of the catalysts results in a transformation of the initially (prior to drying) deposited species and the pertinent species evolution at the nano-level is discussed by means of a number of mechanisms including anchoring, association, cleavage and surface diffusion.
authors: Department of Chemical Engineering, University of Patras, GR-26504, Patras, Greece.
authors: George
authors: G
authors: Tsilomelekis
authors: George D
authors: GD
authors: Panagiotou
authors: Panagiota
authors: P
authors: Stathi
authors: Angelos G
authors: AG
authors: Kalampounias
authors: Kyriakos
authors: K
authors: Bourikas
authors: Christos
authors: C
authors: Kordulis
authors: Yiannis
authors: Y
authors: Deligiannakis
authors: Soghomon
authors: S
authors: Boghosian
authors: Alexis
authors: A
authors: Lycourghiotis