A series of TiO 2-MoO 3 nano-composite photocatalysts were prepared by supercritical fluid dry method(SCFD) and an impregnation technique with TiCl 4 and (NH 4) 6Mo 7O 24 ·4H 2O as the starting materia...A series of TiO 2-MoO 3 nano-composite photocatalysts were prepared by supercritical fluid dry method(SCFD) and an impregnation technique with TiCl 4 and (NH 4) 6Mo 7O 24 ·4H 2O as the starting materials. The catalysts were characterized by the means of XRD, TEM and UV-Vis. Methyl orange was used as model compound for the evaluation of their catalytic activities. The results indicated that the photo-catalyst prepared by SCFD had the advantages of small size(12.84 nm), narrow distribution and good dispersivity. The presence of small amount of Mo in composite catalyst gives rise to the red shift of its absorbance wavelength, decrease of its energy gap and increase of the utility of visible light. Furthermore, higher surface acidity of the photo-catalyst was obtained as the result of the addition of MoO 3. Compared with pure TiO 2, the catalytic activity of the TiO 2-MoO 3 nano-composite photo-catalyst was improved significantly. As the doping concentration of the composite catalysts was controlled at 0.6%(molar percentage), 100% degradation of methyl orange was achieved with in 1.2 h irradiation time.展开更多
In this paper a new solid superacid catalyst SO 2- 4 MoO 3 TiO 2 was prepared.The activity of the catalyst in esterification of acetic acid and iso amyl alcohol was measured and compared with that of SO 2- 4 TiO 2 and...In this paper a new solid superacid catalyst SO 2- 4 MoO 3 TiO 2 was prepared.The activity of the catalyst in esterification of acetic acid and iso amyl alcohol was measured and compared with that of SO 2- 4 TiO 2 and MoO 3 TiO 2.The results showed that SO 2- 4 MoO 3 TiO 2 had better catalytic performance than SO 2- 4 TiO 2 and MoO 3 TiO 2.There was evident coordination between MoO 3 and SO 2- 4 when they coexisted on TiO 2.展开更多
Supported loaded semiconductors （MoO3,ZnO）-TiO2/SiO2 were pre pared by an isovolumetric impregnation method from TiO2/SiO2 pre pared by chemical modification reaction. The chemisorption property and photon a bsorpti...Supported loaded semiconductors （MoO3,ZnO）-TiO2/SiO2 were pre pared by an isovolumetric impregnation method from TiO2/SiO2 pre pared by chemical modification reaction. The chemisorption property and photon a bsorption ability of MoO3-TiO2/SiO2 and ZnO-TiO2/SiO 2 were investigated by BET, UV-Vis DRS, IR and TPD-MS techniques. The gas -phase photocatalytic reaction of CH4 with H2O was performed at 150 ℃ in a fixed-bed annular reactor. The results show that the conversion of met hane and the selectivity of methanol reach to 5.1% and 87.3% respectively over MoO3-TiO2/SiO2, and MoO3-TiO2/SiO2 ex hibits higher photocatalytic acivity than ZnO-TiO2/SiO2.展开更多
文摘A series of TiO 2-MoO 3 nano-composite photocatalysts were prepared by supercritical fluid dry method(SCFD) and an impregnation technique with TiCl 4 and (NH 4) 6Mo 7O 24 ·4H 2O as the starting materials. The catalysts were characterized by the means of XRD, TEM and UV-Vis. Methyl orange was used as model compound for the evaluation of their catalytic activities. The results indicated that the photo-catalyst prepared by SCFD had the advantages of small size(12.84 nm), narrow distribution and good dispersivity. The presence of small amount of Mo in composite catalyst gives rise to the red shift of its absorbance wavelength, decrease of its energy gap and increase of the utility of visible light. Furthermore, higher surface acidity of the photo-catalyst was obtained as the result of the addition of MoO 3. Compared with pure TiO 2, the catalytic activity of the TiO 2-MoO 3 nano-composite photo-catalyst was improved significantly. As the doping concentration of the composite catalysts was controlled at 0.6%(molar percentage), 100% degradation of methyl orange was achieved with in 1.2 h irradiation time.
文摘In this paper a new solid superacid catalyst SO 2- 4 MoO 3 TiO 2 was prepared.The activity of the catalyst in esterification of acetic acid and iso amyl alcohol was measured and compared with that of SO 2- 4 TiO 2 and MoO 3 TiO 2.The results showed that SO 2- 4 MoO 3 TiO 2 had better catalytic performance than SO 2- 4 TiO 2 and MoO 3 TiO 2.There was evident coordination between MoO 3 and SO 2- 4 when they coexisted on TiO 2.
文摘Supported loaded semiconductors （MoO3,ZnO）-TiO2/SiO2 were pre pared by an isovolumetric impregnation method from TiO2/SiO2 pre pared by chemical modification reaction. The chemisorption property and photon a bsorption ability of MoO3-TiO2/SiO2 and ZnO-TiO2/SiO 2 were investigated by BET, UV-Vis DRS, IR and TPD-MS techniques. The gas -phase photocatalytic reaction of CH4 with H2O was performed at 150 ℃ in a fixed-bed annular reactor. The results show that the conversion of met hane and the selectivity of methanol reach to 5.1% and 87.3% respectively over MoO3-TiO2/SiO2, and MoO3-TiO2/SiO2 ex hibits higher photocatalytic acivity than ZnO-TiO2/SiO2.
