Synthesis and characterization of zeolite beta containing oxide clusters of antimony and vanadium

✍ Scribed by Wen Li; Lin Luo; Hiromi Yamashita; Jay A Labinger; Mark E Davis

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 184 KB
• Volume: 37
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(99)00193-6

✦ Synopsis

Individual and mixed metal oxide clusters of antimony and vanadium are synthesized within the pore space of zeolite beta and investigated by powder X-ray diffraction, N 2 physisorption, electron spin resonance spectroscopy, temperature-programmed reduction and X-ray adsorption fine structure. Vanadium species ( VO2+) are highly dispersed in zeolite beta by ion exchange of the hydrogen form with VOSO 4

. Upon calcination in air and subsequent reduction at 550°C in hydrogen, the vanadium species do not aggregate into large oxide clusters. On the contrary, intrazeolitic antimony species obtained via the impregnation of antimony acetate into zeolite beta do aggregate during calcination in air. However, if antimony acetate is impregnated into a zeolite beta containing vanadium at an Sb/V ratio near unity, mixed metal oxide clusters are formed with physicochemical properties different from either intrazeolitic vanadium or antimony or bulk SbVO 4

. At Sb/V ratios above unity, phase-separated antimony oxide is obtained in addition to the intrazeolitic mixed metal oxide clusters.