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以河南某地的钠基蒙脱土为原料,用模板剂前驱法合成了一类新型的多孔Si层柱蒙脱土材料(Si-MMT).通过粉末X射线衍射(XRD)、N2吸附-脱附分析、程序升温氨脱附(NH3-TPD)2、7Al和29Si的魔角旋转核磁共振(29Si MAS NMR和27Al MAS NMR)、吡啶吸附红外光谱法、水热老化法等测试手段,研究了材料水热稳定性和酸性.结果表明:Si-MMT的水热稳定性可维持在600℃,比表面积和比孔容分别为523 m2/g和0.29 cm3/g;与原土相比,Si-MMT层柱蒙脱土多孔材料的总酸量增加了将近1倍;合成材料同时存在B酸和L酸,L酸主要来源于层柱,B酸则主要来源于焙烧过程有机物分解释放质子和黏土中四面体存在Al的同晶取代Si.
A new type of porous Si-layer column montmorillonite (Si-MMT) was synthesized by the templating agent method using Na-montmorillonite in Henan as a raw material. Desorption analysis, magic angle rotation nuclear magnetic resonance (29Si MAS NMR and 27Al MAS NMR) of 2,7Al and 29Si by temperature-programmed ammonia desorption (NH3-TPD), pyridine adsorption infrared spectroscopy, hydrothermal aging test and so on, The hydrothermal stability and acidity of the materials were investigated.The results show that the hydrothermal stability of Si-MMT can be maintained at 600 ℃, the specific surface area and specific pore volume are 523 m2 / g and 0.29 cm3 / g, respectively. The total acidity of Si-MMT layer montmorillonite porous materials increased by almost 1 time. The synthesis materials also contain B acid and L acid. The L acid mainly comes from the column. The B acid mainly comes from decomposition of organic matter during roasting to release protons And the presence of Si tetrahedral Al in the crystal to replace Si.