کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
62301 | 47632 | 2010 | 9 صفحه PDF | دانلود رایگان |
Bulk VPO catalysts (VPO/bulk) and VPO catalysts supported on mesoporous SBA-15 material (VPO/SBA-15) were treated sequentially in a flow of nitrogen loaded with n-butane and of synthetic air loaded with n-butane in order to reach a complete reduction and reoxidation, respectively, of the catalyst surface. The V5+ species on these VPO catalysts were quantitatively investigated by solid-state NMR spectroscopy and correlated with the catalytic activities of the corresponding materials in the selective oxidation of n-butane to maleic anhydride. By 31P{1H} cross-polarization MAS NMR experiments on the n-butane-loaded VPO/SBA-15 catalyst was evidenced that n-butane is preferentially adsorbed at surface sites of δ-VOPO4-like phases. Based on the number of P/V5+ species in δ-VOPO4-like phases as determined by MAS NMR spectroscopy, the turnover frequency of the surface sites on the VPO/SBA-15 catalyst was estimated to be about 0.2 s−1.
Assignment and quantification of active V5+ species of VPO catalysts applied for the selective oxidation of n-butane to maleic anhydride were performed by on-line UV/Vis and 31P MAS NMR spectroscopy.Figure optionsDownload high-quality image (90 K)Download as PowerPoint slide
Journal: Journal of Catalysis - Volume 272, Issue 1, 25 May 2010, Pages 131–139