01572nas a2200229   4500008004100000022001400041245012400055210006900179260007300248300001200321490000800333520073000341653001801071653002701089653002601116653001101142653000801153100002201161700001801183700001801201856012301219       2011                        eng d  a1387-181100aCharacterization of surface acid sites in tin-silicalite-1 (Sn-MFI) molecular sieve by X-ray photoelectron spectroscopy0 aCharacterization of surface acid sites in tinsilicalite1 SnMFI m  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a236-2400 v1413 a<p>The nature, strength and density of surface acid sites in Sn-MFI molecular sieves with different Sn-content were characterized by N 1s high resolution photoelectron peak of chemisorbed pyridine in combination with pyridine-IR and TPAD. Two peaks emerged at 399.5 +/- 0.2 and 401.5 +/- 0.2 eV by deconvoluting composite N is peak were assigned to chemisorbed pyridine on weak and relatively strong Lewis acid sites, respectively. The relative percentage of strong Lewis acid sites was found to increase with the decrease of framework Sn content. A close agreement was observed between the ratios of weak Lewis acid sites to strong Lewis acid sites obtained from XPS and TPAD. (C) 2010 Elsevier Inc. All rights reserved.</p>10aLewis acidity10aPyridine chemisorption10aSiO2/SnO2 molar ratio10aSn-MFI10aXPS1 aNiphadkar, P., S.1 aPatil, K., R.1 aJoshi, P., N.  uhttps://library.ncl.res.in/content/characterization-surface-acid-sites-tin-silicalite-1-sn-mfi-molecular-sieve-x-ray-0