Chemisorption of NH3 on Monomeric Vanadium Oxide Supported on Anatase TiO2: A Combined DRIFT and DFT Study

V/TiO 2 catalysts are used in various reactions, including oxidative dehydrogenation, partial oxidation of ethanol, and selective catalytic reduction of NO x with NH 3 . In this work, we investigated the effect of supported monomeric vanadium oxide (VO 3 ) on the acidity of anatase TiO 2 (101) surface by using density functional theory calculations combined with in situ diffuse reflectance infrared Fourier transform (DRIFT) experiments. The hydrogenation of TiO 2 to form hydroxyl groups on the surface was energetically more favorable in the presence of the supported monomeric vanadium oxide. Charge transfer between TiO 2 support and VO 3 was considered as an origin of −OH stabilization, which made Brønsted acid sites more abundant on the V/TiO 2 surface than on TiO 2 . Moreover, it was observed that the cationic vanadium center in VO 3 can act as much weaker Lewis acid sites than the tit…