TiO 2 Nanoparticles in Mesoporous TUD‐1: Synthesis, Characterization and Photocatalytic Performance in Propane Oxidation

A series of TiO 2 ‐TUD‐1 samples was synthesized with a variable Ti loading in the range Si/Ti=100, 20, 2.5, and 1.6, by using a one‐pot surfactant‐free procedure. The materials obtained were characterized by elemental analysis; X‐ray diffraction (XRD); N 2 sorption measurements; high‐resolution TEM (HR‐TEM); 29 Si NMR, UV‐visible and Raman spectroscopy. As a function of increasing metal loading either isolated Ti atoms, or (above a Ti loading of ∼2.5 wt‐ %) combinations of isolated Ti atoms and anatase (TiO 2 ) nanoparticles were obtained; both were incorporated in the highly porous siliceous matrix. The photocatalytic performance of these materials was tested by studying the propane oxidation process following irradiation at λ =365 nm, selectively activating the anatase nanoparticles. In comparison to commercial anatase powder, TiO 2 nanoparticles in TUD‐1 showed high photochemical selectivity towards acetone, the sample with a Si/Ti ratio of 1.6 being the most selective. Size and confinement effects are consistent with the difference in performance of the TUD‐1 materials and TiO 2 , limiting the number of electron transfers available for each propane molecule.