from first principles PP-I-1

PP-III-93Direct Synthesis of Hydrogen Peroxide on Model Pd SurfacesRossi U. 1 , Artiglia L. 2 , Granozzi G. 2 , Canu P. 11 Dipartimento di Ingegneria Industriale, via Marzolo 9, 35131 Padova, Italy2 Dipartimento di Scienze Chimiche, via Marzolo 1, 35131 Padova, Italypaolo.canu@unipd.itWe experimentally demonstrated that model catalysts in the form of ideal Pd surfaces, eithersingle (100) or poly crystalline, are active in H 2 O 2 direct synthesis at 15 °C and pressure inexcess of 20 bars, in methanol. Activity scaled on the available surface is much larger thansome of the best powder catalyst suggested so far (Pd-Au on sulphated zirconia).The surface with a long range order, i.e. single crystal Pd (100), was far more active that thecorresponding polycristalline surface, suggesting an actual correlation between structure andreactivity, extremely relevant for performances.Prereduction treatments and corresponding X-ray photoelectron spectrocopy of the surfacesconfirmed the presence of surface oxidized specie, which structure appear to be related to theunderlying Pd texture.These results, well validated, open new perspectives for an effective catalyst design, takingsurface science speculations, based on either ultra high vacuum experiments in the gas phaseand DFT calculations, closer to an experimental validation. This contribution goes wellbeyond the investigation of the H 2 O 2 direct synthesis mechanism.252