Is selective hydrogenation of molecular oxygen to H2O2 affected by strong metal–support interactions on Pd/TiO2 catalysts? A case study using commercially available TiO2

Abstract

Keywords:Palladium Direct synthesis of hydrogen peroxide Titanium dioxide Anatase SMSI (strong metalesupport interaction) a b s t r a c t In this study, titania-supported Pd catalysts were prepared and their performance evaluated upon H 2 O 2 direct synthesis. Typically, the materials contained different ratios of anatase and rutile phases, which gave rise to different surface properties of the supports, e.g., surface area, number of Lewis acidic and basic sites as well as different compositions of the phases, i.e. the amount of anatase phase and crystallite size. Two materials, Pd-A98 and Pd-A05 samples, respectively, apparently hint the existence of the so-called SMSI (strong metalesupport interaction) phenomenon giving rise to 1080 and 683 mol H2O2 $mol Pd À1 $h À1 of H 2 O 2 productivity and 22 and 14% of H 2 O 2 selectivity, respectively.However, the best material, Pd-A82, gave rise to 949 mol H 2 O 2 $mol Pd À1 $h À1 of H 2 O 2 productivity and 26% of H 2 O 2 selectivity.

Controlling the Microstructure and Properties of Titanium Dioxide for Efficient Solar Cells

“…The conduction band is formed by the 3d orbital of titanium, and the valence band is obtained by the 2p orbital of oxygen. TiO 2 is commercially available and widely used in industrial applications [11].…”

Elemi reakciók vizsgálata oxidokon hordozott ródiumon és inverz katalitikus rendszerekben

“…Salmi T és munkatársai a Pd-mal borított TiO 2(110) egykristály esetében, egy extra deszorpciós állapotot figyeltek meg 460 K-nél a tiszta Pd-os esethez képest. Ezt az állapotot, a kontroll kísérletek alapján, a Pd által megkötött, szétbontott és hordozóra átdiffundált hidrogén deszorpciójához rendelték71 . MoO 2 fémes vezető77 és a MoO 3 egy szigetelő78 .…”