Preparation and characterization of Cr- and Fe-pillared bentonites by using CrCl3, FeCl3, Cr(acac)3 and Fe(acac)3 as precursors
- 作者：Mü ; rü ; vvet Yurdakoç ; Mehmet Akç ; ay ; Yalç ; ı ; n Tonbul ; Fatih Ok ; Kadir Yurdakoç
- 关键词：Bentonite ; Pillared bentonite ; Cr-pillared bentonite ; Fe-pillared bentonite ; Surface acidity ; Cr(acac)3 ; Fe(acac)3
- 刊名：Microporous and Mesoporous Materials
- 出版年：2008
- 期刊代码：78_13871811
- 类别：ch
- 出版时间：15 April 2008
- 卷：111
- 期：1-3
- 页码：211-218
- 文件大小：843 K
摘要
Four pillared bentonites (Cr-PILB, Cr(acac)3-PILB, Fe-PILB and Fe(acac)3-PILB were prepared and characterized by X-ray diffraction (XRD), nitrogen sorption measurements and thermogravimetric (TG) analysis. The surface acidities of the samples and their structures were also investigated in the gas phase adsorption data of pyridine by the aid of FT-IR spectroscopic techniques. The XRD data and FT-IR spectra of the samples reflected mainly the structure of bentonite. The nitrogen adsorption–desorption isotherms of the samples were Type II shaped and showed in general mesoporous structures with pore openings of 4 nm. Two steps mass losses were observed in the TGA thermograms of B, Cr-PILB and Fe-PILB, while three steps mass losses were detected in the case of Cr(acac)3-PILB and Fe(acac)3-PILB. IR study by the adsorption of pyridine on the samples showed both Lewis and Brönsted acid sites on their surfaces.