Mas Nmr Studies of Silanol Groups in Zeolites Zsmj Synthesized with an Ionic Template
نویسندگان
چکیده
‘H magic angle spinning nuclear magnetic resonance (MAS NMR) measurements on ZSM-5 synthesized with tetrapropylammonium ions as structure-directing template, calcined and hydrogen exchanged, indicate high concentrations of silanol groups (up to 4.6~ 10zo SiOH g-‘)_ ‘H NMR, “Na and % MAS NMR studies of zeolites ZSM-5 with different Si/Al ratios support a model which attributes the majority of these silanol groups to SiOH pairs located on the site of the removed TPA+ cations with an intra-pair distance of 0.3 I nm.
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