Catalytic Performance Of The Organotin Graftted On SBA-15Mesoporous Molecular Sieves

Mesoporous molecular sieves SBA-15was synthesized. Triphenyltin chloride andtributyltin chloride were grafted on SBA-15mesoporous molecular sieves respectively, twokinds of organotin surface function complexes SnPh3/SBA-15（STP-SBA-15） andSnBu3/SBA-15（STB-SBA-15） were got. The structure, composition and properties of thesamples were characterized by fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TG）, X-ray diffraction（XRD）, Hammett titration, NH3chemisorption（NH3-TPD）, X-ray EDS analysis, inductively coupled plasma massspectrometry （ICP-MS）, scanning electronic microscope （SEM）, transmittance electronmicroscopy（TEM）, N2adsorption-desorption and Solid nuclear magnetic resonance （NMR）,and so on. The analytic results showed that the hexagonal p6mm mesostructure of parentsiliceous SBA-15was maintained very well in STP-SBA-15and STB-SBA-15, mesoporousordered arrangement.STP-SBA-15was analysis by FTIR, the result showed that its had the absorption peaksin3056.2cm^-1,1600cm^-1,1580.2cm^-1,1500.8cm^-1,1451.3cm^-1respectively, which werethe characteristics of benzene absorption peaks. After absorption and desorption for pyridine,STP-SBA-15had absorption peaks in1564cm^-1,1518cm^-1,1482cm^-1respectively, whichwere peculiar absorption peaks for bronsted acid and lewis acid. The TPD acid, BET surfacearea, bore diameter, pore volume of STP-SBA-15were2.3733mmol/g,508.2m2/g,5.043nm,0.685mL/g respectively. When the mole ratio of Si and Sn was2.0:1.0, reaction temperaturewas190℃, reaction time was7h, the content of catalyst was2%, the grafting percent oftriphenyltin chloride was17.08%. The analysis results of13C NMR and29Si NMR showedthat triphenyltin chloride was success drawing into mesoporous skeleton.STB-SBA-15was analysis by FTIR, the result showed that its had the absorption peaksin2950cm^-1and2890cm^-1, which were the characteristics of methyl absorption peaks. Afterabsorption and desorption for pyridine, STB-SBA-15had absorption peaks in1581cm^-1,1537cm^-1,1483cm^-1respectively, which were peculiar absorption peaks for bronsted acidand lewis acid.The TPD acid, BET surface area, bore diameter, pore volume of STB-SBA-15were2.0858mmol/g,470.6m2/g,6.521nm,0.767mL/g respectively. When the mole ratio of Siand Sn was1.0:10.0, reaction temperature was220℃, reaction time was5h, the graftingpercent of tributyltin chloride was25.70%. The analysis results of13C NMR and29Si NMRshowed that tributyltin chloride was success drawing into mesoporous skeleton.Catalytic character of STP-SBA-15and STB-SBA-15were evaluated by using acylationof toluene with acetic anhydride. The results showed that both of STP-SBA-15and STB-SBA-15had high catalytic activity in synthesis of methyl acetophenone, the conversionof acetic anhydride were72.4%and73.09%, respectively. When the catalysts were used fourtimes repeatly, the conversion of acetic anhydride were decreased to60.27%and62.23%respectively.