Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
64717 | Journal of Molecular Catalysis A: Chemical | 2016 | 13 Pages |
•V-Mo-zeolite catalysts were tested in the ammoxidation of ethylene to acetonitrile.•The prepared materials exhibited generally good activity and selectivity in the studied reaction.•Exchanging V and Mo ions with MFI-Type zeolite led to the highly active catalysts.•Larger M-Ox (MMo or V) species are significantly less active than smaller particles for ethylene ammoxidation.
This work reports on the investigation of the influence of the parent zeolite topology (MFI, MOR and USY) on the ammoxidation of ethylene to acetonitrile over vanadium and molybdenum oxide supported zeolite catalysts. The physico-chemical properties were investigated by several characterization techniques such as XRD, N2-adsorption, 27Al MAS NMR, TEM, XPS, DR UV–vis, Raman and DRIFT spectroscopies and H2-TPR. From the catalytic results, V and Mo oxide species in USY and MOR zeolites led to less active catalysts when compared to MFI structure. These results suggest that the catalytic performances depend strongly on the zeolite structure and thus, the size of the formed metal oxide particles. The catalytic activity and selectivity are controlled by the porous structure and the chemical state of V and Mo species. The extent of dispersion and reducibility of supported M-Ox (MV or Mo) species are governed by the chemical identity of the support as detected by TPR analysis and optical absorption spectroscopy. The good catalytic performance of MFI-type zeolite might be related to the high dispersion of metal oxide species and to the internal pore space which permits an effective accessibility of the reactants.
Graphical abstractCatalytic activity is highly affected by the zeolite matrix. The high dispersion of V and Mo oxide species on the exchange sites of zeolite and the high accessibility of active sites to the reactants play a key role in ethylene ammoxidation.Figure optionsDownload full-size imageDownload high-quality image (115 K)Download as PowerPoint slide