کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
43177 | 45957 | 2009 | 6 صفحه PDF | دانلود رایگان |
Under microwave irradiation, 12-tungstophosphoric acid (HPW) could be successfully synthesized in situ and encapsulated in the supercage of ultra stable Y (USY) in several minutes. But the framework of USY collapsed easily in traditional hydrothermal synthesis routine. 31P MAS NMR, transmission electron microscopy (HR-TEM), N2 adsorption, inductively coupled plasma (ICP) and X-ray diffraction (XRD) characterizations found that the formed HPW molecule located separately in the supercage of USY. Temperature-programmed desorption of NH3 (NH3-TPD) showed that HPW-USY exhibited stronger acidity than that of pure USY, and adsorbed pyridine infrared (Py-IR) disclosed that the concentration of Brönsted acid sites was enhanced. This hybrid solid acid exhibited higher activity in the synthesis of 4,4′-dimethyldiphenylmethane via toluene and formaldehyde and could be utilized as a solid acid catalyst in aqueous solutions.
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Journal: Applied Catalysis A: General - Volume 352, Issues 1–2, 15 January 2009, Pages 259–264