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利用低角度X射线衍射、红外光谱、喇曼光谱及孔结构分析,研究了用铁盐水解法制备的铁层柱蒙脱石的结构与性质。所制得的铁层柱蒙脱石以介孔型层离结构为主,微孔型柱撑结构为辅。前者为蒙脱石片层与铁离子水解产生的聚合羟基铁簇合物堆垛而成的卡房状结构,与d值为6.4±1.0nm的X射线衍射宽峰相对应;微孔型柱撑结构则与d值约1.5nm的(001)衍射峰相对应。所合成的系列铁层柱蒙脱石中最大的比表面积和孔容分别为215.7m2/g和0.291mL/g。500℃热处理后,仍保存铁层柱蒙脱石的介孔结构。铁层柱蒙脱石富含阴离子(NO3-),并作为平衡铁水解聚合物正电荷的反离子而稳定存在,可为磷钨酸离子[PW12O40]3-所交换。铁层柱蒙脱石的新型结构和特殊性质在催化剂、载体与吸附剂等领域具新的应用前景。
The structure and properties of iron-layer montmorillonite prepared by iron salt hydrolysis were studied by low-angle X-ray diffraction, infrared spectroscopy, Raman spectroscopy and pore structure analysis. The obtained iron pillared montmorillonite is mainly composed of mesoporous delaminated structure, supplemented by microporous pillared structure. The former is a cathartic structure composed of montmorillonite lamellae and polymerized hydroxy iron clusters produced by hydrolysis of ferric ions, corresponding to a broad X-ray diffraction peak with a d value of 6.4 ± 1.0 nm; a microporous column The bracing structure corresponds to the (001) diffraction peak with a d value of about 1.5 nm. The largest specific surface area and pore volume of the synthesized iron-layered montmorillonite were 215.7 m2 / g and 0.291 mL / g, respectively. After heat treatment at 500 ℃, the mesoporous structure of iron-layer montmorillonite is still preserved. Iron-layer montmorillonite is rich in anions (NO3-) and is stable as a counter-ion for the equilibrium of the positive charge of the hydrolyzed polymer. It can be exchanged for phosphotungstic acid ion [PW12O40] 3-. The new structure and special properties of iron-layer montmorillonite have new application prospects in the fields of catalysts, supports and adsorbents.