Published in
American Chemical Society, Journal of Physical Chemistry C, 8(118), p. 4143-4150, 2014
DOI: 10.1021/jp410016g
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Incorporation of Mo into the Vacant T-Atom Sites of the Framework of BEA Zeolite as Mononuclear Mo Evidenced by XRD and FTIR, NMR, EPR, and DR UV-Vis Spectroscopies
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- Must obtain written permission from Editor
- Must not violate ACS ethical Guidelines
- Must obtain written permission from Editor
- Must not violate ACS ethical Guidelines
Abstract
A MoSiBEA zeolite has been prepared by a two-step postsynthesis procedure that consists of first creating the vacant T-atom sites with associated silanol groups by treatment of TEABEA zeolite with nitric acid and then incorporating Mo ions into the vacant T-atom sites by solid-state ion exchange at 773 K using molybdenum(II) acetate. The incorporation of Mo ions into the vacant T-atom sites of the framework of SiBEA zeolite as isolated mononuclear Mo(VI) species was evidenced by the combined use of XRD and FTIR, NMR, and diffuse reflectance UV−visible spectros-copies. The consumption of OH groups was monitored by FTIR spectroscopy. The reducibility of Mo was investigated by TPR and EPR spectroscopy. The size of very small well-dispersed Mo(0) nanoparticles formed upon treatment of MoSiBEA between 298 and 1240 K in hydrogen stream (5% H 2 /Ar) was measured by TEM.