Research On Preparation Of Novel Mesoporous Materials And Application In Environmental Catalysis

Mesoporous material SBA-15 has regular pore structure,large specific surface area and thermal stability.M-SBA-15,Au/M-SBA-15 were sybthesised by surface modification method,and these materials were applied in different catalysis rection。Ordered mesoporous silica SBA-15 with various pore sizes were synthesized using two different additives:polypropylene glycol(PPG) and polyethylene glycol (PEG).The final products were characterized by low-angle X-ray diffraction,N₂ adsorption-desorption and transmission electron microscopy.It was found that the addition of PPG could expand the pore width of SBA-15 and decrease the wall thickness.Added PEG could reduce the pore size of SBA-15 and increase the wall thickness.PPG and PEG as additive all could maintain the two-dimensional hexagonal structure(p6m).TiO₂,Al₂O₃,Nb₂O₅,Ta₂O₅,ZrO₂and Fe₂O₃ were attach to the surface of SBA-15 by gas-phase surface modification using their chloride as precursors.The samples are characterized by BET,HRTEM,XRD,UV-Vis diffuse reflection absorption spectrum.The results indicated that Ti,Al,Nb,Ta,Zr,Fe are in the channel of the SBA-15 without block it.A series of Ti-SBA-15 were prepared by vapor-solid surface modification using anhydrous titanium tetrachloride as precursor.Gold catalysts with 1%loading supported on Ti-SBA-15 were prepared by the in-situ deposition-precipitation method. The samples were characterized by TEM,XRD,BET,UV-Vis,XRF and ICP.The results indicated that TiO₂ banded on the inner surface in the channel of the SBA-15 without blocking and Au particles were limited within the mesoporous channels of Ti-SBA-15.The catalytic activity of the catalyst samples for CO oxidation was evaluated,and the results indicated that the activity of the catalysts was high in a wide range of temperature(50～500℃).The samples exhibited high low-temperature activity,high-temperature activity,high storage stability and cycle reproducibility.A series of M-SBA-15(M=Al,Zr,Fe,Ti) were prepared by vapor-solid surface modification using anhydrous titanium tetrachloride as precursor.Gold catalysts supported on M-SBA-15 were prepared by the in-situ deposition-precipitation method. The catalytic activity of the catalyst samples for CO oxidation was evaluated,and the results indicated that titanium was a good catalyst support,followed by zirconium, aluminum the worst.The supported nanosized Au/Fe₂O₃-TiO₂ were prepared and evaluated,and the results indicated that the activity of the catalysts was high in a wide range of temperature(50～500℃).The samples exhibited high low-temperature activity,high-temperature activity.