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Synthesis and characterization of V-MFI obtained in fluoride-containing medium

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Bibliographic Details
Title:	Synthesis and characterization of V-MFI obtained in fluoride-containing medium
Authors:	Veltri, M.¹ maria.veltri@unical.it, De Luca, P.¹ p.deluca@unical.it, B.Nagy, J.² janos.bnagy@fundp.ac.be, Nastro, A.¹ a.nastro@unical.it
Source:	Thermochimica Acta. Oct2004, Vol. 420 Issue 1/2, p145-154. 10p.
Subjects:	Fluorides, Crystallization, Zeolites, Silicate minerals
Abstract:	Crystallization fields for the formation of V-MFI were determined from gels of composition: xNa2O–yVO2–7NaF–ySO3–zSiO2–2TPABr–260H2O at 190 °C with 3.6≤x≤14.4 and 2.1≤y≤7.1 for z=12.0 and with 0.3≤y≤4.2 and 4.0≤z≤12.0 for x=3.6; TPA=tetrapropylammonium ions. The crystallization curves were analysed together with the various intermediate phases using XRD, pH of mother liquors, thermal analysis and SEM. The final samples were analysed, in addition, by multinuclear NMR. It is concluded, that V can be introduced into the MFI framework as V(IV) ions, accompanied by the presence of two SiOH defect groups per V atom introduced. The 51V-NMR signal due to V(V) can only be detected when additional vanadium-containing siliceous phases are formed. [Copyright &y& Elsevier]
	Copyright of Thermochimica Acta is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database:	Engineering Source

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