Lindahl Christiansen Troels, Kjær Emil T S, Kovyakh Anton, Röderen Morten L, Høj Martin, Vosch Tom, Jensen Kirsten M Ø
Department of Chemistry and Nanoscience Center, University of Copenhagen, Copenhagen, DK-2100, Denmark.
Niels Bohr Institute and Nanoscience Center, University of Copenhagen, Copenhagen, DK-2100, Denmark.
J Appl Crystallogr. 2020 Feb 1;53(Pt 1):148-158. doi: 10.1107/S1600576719016832.
Molybdenum oxides and sulfides on various low-cost high-surface-area supports are excellent catalysts for several industrially relevant reactions. The surface layer structure of these materials is, however, difficult to characterize due to small and disordered MoO domains. Here, it is shown how X-ray total scattering can be applied to gain insights into the structure through differential pair distribution function (d-PDF) analysis, where the scattering signal from the support material is subtracted to obtain structural information on the supported structure. MoO catalysts supported on alumina nanoparticles and on zeolites are investigated, and it is shown that the structure of the hydrated molybdenum oxide layer is closely related to that of disordered and polydisperse polyoxometalates. By analysing the PDFs with a large number of automatically generated cluster structures, which are constructed in an iterative manner from known polyoxometalate clusters, information is derived on the structural motifs in supported MoO .
负载于各种低成本高比表面积载体上的氧化钼和硫化钼是多种工业相关反应的优良催化剂。然而，由于钼酸盐域小且无序，这些材料的表面层结构难以表征。本文展示了如何通过差分对分布函数（d-PDF）分析应用X射线全散射来深入了解结构，即减去载体材料的散射信号以获得负载结构的结构信息。研究了负载在氧化铝纳米颗粒和沸石上的钼酸盐催化剂，结果表明水合氧化钼层的结构与无序和多分散的多金属氧酸盐密切相关。通过用大量自动生成的簇结构分析PDF，这些簇结构由已知的多金属氧酸盐簇以迭代方式构建，从而获得负载钼酸盐中结构基序的信息。
