A XAFS study of the local environment and reactivity of Pt- sites in functionalized UiO-67 MOFs

16th International Conference on X-ray Absorption Fine Structure

Borfecchia, E.^1 ; Øien, S.^2 ; Svelle, S.^2 ; Mino, L.^1 ; Braglia, L.^1,4 ; Agostini, G.^1,3 ; Gallo, E.^1,3 ; Lomachenko, K.A.^1,4 ; Bordiga, S.^1 ; Guda, A.A.^4 ; Soldatov, M.A.^4 ; Soldatov, A.V.^4 ; Olsbye, U.^2 ; Lillerud, K.P.^2 ; Lamberti, C.^4,5

Dept. of Chemistry, NIS and INSTM Reference Centers, University of Turin, Turin, Italy^1

InGAP Centre for Research Based Innovation, Dept. of Chemistry, University of Oslo, Oslo, Norway^2

European Synchrotron Radiation Facility (ESRF), Grenoble, France^3

Southern Federal University, Rostov-on-Don, Russia^4

Dept. of Chemistry, CrisDi Centre for Crystallography, University of Turin, Turin, Italy^5

关键词: Catalytic reactions;    Heterogenization;    Ligand exchanges;    Local environments;    Metalorganic frameworks (MOFs);    Oxidation state of Pt;    Oxidative additions;    Room temperature oxidation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012125/pdf
DOI  :  10.1088/1742-6596/712/1/012125

来源: IOP

【 摘 要 】

We synthesized UiO-67 Metal Organic Frameworks (MOFs) functionalized with bpydcPt(II)Cl2and bpydcPt(IV)Cl4complexes (bpydc = bipyridine-dicarboxylate), as attractive candidates for the heterogenization of homogeneous catalytic reactions. Pt L3-edge XAFS experiments allowed us to thoroughly characterize these materials, in the local environment of the Pt centers. XAFS studies evidenced the rich reactivity of UiO-67-Pt(II) MOFs, including reduction to bpydcPt(0) under H2flow in the 600-700 K range, room-temperature oxidation to bpydcPt(IV)Br4through oxidative addition of liquid Br2and ligand exchange between 2 Cl-and even bulky ligands such as toluene-3,4-dithiol. Preliminary XANES simulations with ADF code provide additional information on the oxidation state of Pt sites.