Synthesis and Characterization of Pd over Novel TiO2 Mixtures: Insights on Metal-Support Interactions

MATIAS GASTÓN RINAUDO; ANA MARIA BELTRÁN; MARÍA ASUNSIÓN FERNÁNDEZ; CADUS, LUIS E.; MARIA R. MORALES

Switzerland

Conferencia; 1st International Electronic Conference on Catalysis Sciences; 2020

Palladium nanoparticles were supported on unusual mixtures of anatase, TiO2 (II) andrutile titania phases by wet impregnation, obtaining catalysts with metal contents of ca. 0.25 wt%labeled Pd/Ti5, Pd/Ti45 and Pd/Ti120. Crystalline structures were confirmed by X-Ray Diffraction.Pd particle sizes in the range 4?20 nm were observed by Scanning-Transmission ElectronMicroscopy. External surface areas (SBET) in the range 10?17 m2 g−1 were higher enough to achieve a good distribution of palladium over titanium oxide outer surface, as evidenced by Energydispersive X-ray Spectroscopy elemental profiles. Pd0 /Pdδ+ atomic ratio measured by X-RayPhotoelectron Spectroscopy showed a decrease from Pd/Ti5 to Pd/Ti120, in line with the decreasein anatase phase present in the catalysts. This behavior suggested that palladium tended to formmore TiPdxO structures in Pd/Ti5 whilst PdOx structures were more likely to be present on supportswith greater amounts of TiO2 (II) and rutile, due to the distinct metal-support interactions. Anincrease in reducibility and oxygen mobility from Pd/Ti5 to Pd/Ti120 was observed by TemperatureProgrammed Measurements and associated to the different high-energy ball milled supports.Catalysts with improved properties reported herein could exhibit an excellent performance inoxidation reactions, e.g. glycerol selective oxidation