新型HPW/SiO2复合介孔材料的合成与表征

合成了一种新型的HPW/SiO2复合介孔材料,通过XRD,TEM,UV-Vis和FTIR等表征证明,HPW均匀且稳定地包藏到介孔材料由SiO2网络组成的孔壁之中.催化结果表明,其在大分子催化反应中有较高的活性,在酯化反应中连续循环使用未发现活性组分流失,表明其在多相催化和大分子催化反应中有较好的工业应用前景.

Synthesis and Characterization of a New Mesoporous HPW/SiO2 Composite Material

A new mesosilica-encapsulated Keggin type heteropolyacid-HPW/SiO_2 was synthesized by adding HPW into a sol-gel system to form mesoporous silica involving hydrolysis of tetraethyl orthosilicate under the strong acidic synthesis conditions(pH<0). The mesosilica-impregnated -{heteropolyacid-} thus synthesized are insoluble and readily separable mesoporous composite materials with uniform mesopores and high specific surface areas. Their structures and physical-chemical properties was characterized by various methods, their catalytic activity were measured by the cracking of cumene and 1,3,5-triisopropylbenzene, and esterification reactions of acetic acid with ethanol and benzoic acid with t-butanol. The results show that the HPW is tightly encapsulated into the network of mesosilica walls and does not leach from the walls of mesosilica. The HPW/SiO_2 composite materials are the promising and new catalysts for acid-catalytic reactions, and the potential replacer of the homogenous reaction catalysts to solve the separation and recycle problems.