Study of the Surface Structure of V2O5/γ-Al2O3 Catalysts by LEIS

Abstract

MASTERStudy of the surface structure of V2O5/-Al2O3 catalysts by LEIS Jacobs, J. Award date: 1991Disclaimer This document contains a student thesis (bachelor's or master's), as authored by a student at Eindhoven University of Technology. Student theses are made available in the TU/e repository upon obtaining the required degree. The grade received is not published on the document as presented in the repository. The required complexity or quality of research of student theses may vary by program, and the required minimum study period may vary in duration. General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. ABSTRACTWithin the scope of the catalytic research of the Schuit lnstitute of Catalysis at the Eindhoven Univarsity of Technology, the surface structure of V20s/y-AI20 3 catalysts has been investigated by low energy ion scattering (LEIS). LEIS is a unique surface analysis technique because its information depth is limited to the topmost atomie layer.Supported vanadium oxides are widely used as oxidation catalysts. This investigation is performed in cooperation with the Delft Univarsity of Technology. The scientists from Delft are interestad in the use of Pd/V 2 0 5 /y-AI 2 0 3 catalysts in the heterogeneaus Wacker oxidation.The LEIS experiments on the V 2 0 5 /y-AI 2 0 3 catalysts have been used to study the surface structure of these catalysts as a tunetion of V 2 0 5 loading. At low loadings ( < 7 wt%) the vanadium species are found to be optimally dispersedover the support, while at medium loadings ( < 11 wt%) multilayered structures are formed. In this thesis a three-dimensional model is presented for the surface structure of V 2 0 5 /y-AI 2 0 3 catalysts. SAMENVATTINGIn het kader van het katalytisch onderzoek van het Schuit Katalyse Instituut aan de Technische Universiteit Eindhoven is de oppervlakte struktuur van V 2 0 5 /y-AI 2 0 3 katalysatoren met behulp van lage ionen verstrooiing (LEIS) onderzocht. LEIS is een unieke oppervlakte analyse techniek omdat de informatie diepte beperkt blijft tot de bovenste atoomlaag.Gedragen vanadium oxides worden veel gebruikt als oxidatie katalysator. Dit onderzoek is in samenwerking met de Technische Universiteit Delft gedaan. De wetenschappers uit Delft zijn geïnteresseerd in het gebruik van Pd/V 2 0 5 /y-AI 2 0 3 katalysatoren in de heterogene Wacker oxidatie.Met de LEIS experimenten van V 2 0 5 /y-AI 2 0 3 katalysatoren...