CALCINATION AND DEBORONATION OF [B]-MFI SINGLE-CRYSTALS
CALCINATION AND DEBORONATION OF [B]-MFI SINGLE-CRYSTALS
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DOI:
10.1016/0144-2449(93)90072-b
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发表时间:
1993-02-01
期刊:
影响因子:
--
通讯作者:
VANBEKKUM, H
中科院分区:
文献类型:
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作者:
DERUITER, R;KENTGENS, APM;VANBEKKUM, H
Calcination and deboronation of [B]-MFI and silanol nest reoccupation of deboronated MFI were studied by variable temperature FTi.r. spectroscopy, X-ray diffraction, and H-1, B-11, and Si-29 MAS n.m.r. spectroscopy techniques. Boron loss from the framework upon calcining [B]-MFI was minimized by using an improved calcination procedure, during which boron is kept in a stable tetrahedral/saturated coordination and boron hydrolysis and extraction as well as T-atom reorganizations are avoided. Framework boron can be extracted from the calcined boron MFI material by refluxing in aqueous hydrochloric acid (pH less-than-or-equal-to 5), leaving thermally stable (up to 400-degrees-C, N2) homogeneously distributed silanol nests, which are useful reactive sites for postsynthesis reoccupation.