Synthesis Of Mesoprous Materials With Special Morphology And Its Application In Catalysis

Mesoporous material is a type of important materials, it has great application prospectivein catalysis, adsorption, drug delivery, etc, due to its characters, such as regular pores, highsurface area, and adjustable pore size etc. The preparation and application of mesoporousmaterial have been an attractive topic since this type of materials was first synthesized andreported in1992. Synthesis of mesoporous materials with special morphology and structurehave becoming a hot topic recently because the special morphology and structure is oftenimportant to the mesoporous materials. In the aspect of catalysis application of mesoporousmaterial, it is an important solution to synthesis high performance heterogeneous catalyststhough introducing hetero elements into framework of the mesoporous material, or supportingactive components on the mesoporous silica.In this paper, using triblock copolymer P123as main template, a series of mesoporoussilica with different morphologies were synthesized though adding assistant templates,co-solvents, or polyelectrolytes, etc. The materials were characterized by SEM, XRD, N2adsorption-desorption etc., and the influences of synthesis conditions on the structure ofmesoporous materials were also studied. Spherical SBA-15particles were synthesized byadding glycol as co-solvent; and with the increasing the adding amount of glycol, thespherical particles grew smaller, while the pore size was larger. When the polyethylene glycolwas added as assistant template, the pore size increased while the morphologies changed little.Wormlike mesoporous silica was synthesized by adding polyelectrolyte, while shuttle-likemesoporous silica was synthesized after adding ethanediamine.Mesoprous silica nanoparticles (MSN) were synthesized by using CTAB as template.Using the synthesized MSN as support, a series of MSN supported binary metal catalystswere prepared by a simple impregnation-hydrogenation method. The catalysts werecharacterized by XRD, TEM, XPS, H2-TPR. The Pd/MSN catalyst prepared with MSN assupport showed significantly improved performance towards the hydrogenation of phenol,compared with the Pd/C commercial catlyst, furthermore, it was found that the addition of Rucould further enhance the activity of the catalyst, the PdRu/MSN shows5times higher mass activity than the mono-Pd/MSN catalyst under mild reaction condition (50℃,1.0MPa H2).A series of PtnIr1-n/MSN catalyst with MSN as support were also prepared andinvestigated, it was found that the catalyst with the molar ratio of Pt/Ir of4showed bestactivity. Also, PtIr/MSN catalyst showed much higher activity than the mono-Pt/MSN catalystor the mono-Ir/MSN catalyst.