NMR signatures of the active sites in Sn-β zeolite

Abstract

Dynamic nuclear polarization surface enhanced NMR (DNP-SENS), Mössbauer spectroscopy, and computational chemistry were combined to obtain structural information on the active-site speciation in Sn-β zeolite. This approach unambiguously shows the presence of framework Sn(IV)-active sites in an octahedral environment, which probably correspond to so-called open and closed sites, respectively (namely, tin bound to three or four siloxy groups of the zeolite framework).

Keywords: DNP SENS; Mössbauer spectroscopy; active sites; solid-state NMR spectroscopy; zeolites.