Mesoporous Technische Universiteit Delft（TUD-1）-supported chromium oxide-doped titania（Cr-TiO2） was developed as a promising photocatalyst for phenol photodegradation under visible light irradiation.Low-angle X-ra...Mesoporous Technische Universiteit Delft（TUD-1）-supported chromium oxide-doped titania（Cr-TiO2） was developed as a promising photocatalyst for phenol photodegradation under visible light irradiation.Low-angle X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the amorphous and mesoporous silicate framework of TUD-1 in TUD-1-supported Cr-TiO2.The mesostructure of TUD-1 was further verified via N2 adsorption-desorption analysis,which showed a type-IV isotherm with a narrow average pore size distribution of 3.9 nm and high surface area of 490 m^2/g.Transmission electron microscopy analysis results indicated that TUD-1-supported Cr-TiO2 contained nanoparticles and porous channels.An increase in band gap energy was observed after loading Cr-TiO2 into TUD-1.Compared with that of unsupported Cr-TiO2,TUD-1-supported Cr-TiO2 showed higher photocatalytic activity for phenol degradation under visible light irradiation.The TUD-1 supported Cr-TiO2 photocatalyst with a Si/Ti molar ratio of 30 exhibited the highest photodegradation of phenol（82%） of the prepared samples.The photodegradation of phenol by the supported catalyst followed the Langmuir adsorption isotherm with first-order kinetics.展开更多
Neodymium was incorporated into the three-dimensional mesoporous siliceous material TUD-1.In order to understand the chemical and morphological structure of the prepared material,several characterization techniques we...Neodymium was incorporated into the three-dimensional mesoporous siliceous material TUD-1.In order to understand the chemical and morphological structure of the prepared material,several characterization techniques were performed.The characterization results show the formation of highly distributed isolated Nd3+ions incorporated in the silica matrix in tetrahedrally coordinated structure,moreover no aggregation of separate phase(s)was/were observed.The prepared material was investigated as an adsorbent for methyl green(MG)dye in aqueous solution as a model cationic dye.The results show higher adsorption capacity for Nd-TUD-1 by almost 24 times higher than the neat parent TUD-1 material and more than 100 times higher than bulky Nd_(2)O_(3)under neutral pH.The adsorption results were fitted perfectly with pseudo-second-order model.Moreover,the adsorption isotherms were perfectly fitted with Freundlich isotherm model which indicates the formation of a multilayer of the dye molecules onto the Nd-TUD-1 surface as a physisorption with endothermic nature.展开更多
Selective propylene epoxidation to propylene oxide(PO) with hydrogen peroxide(H_2O_2) was carried out in a catalytic semi-batch reactor.High propylene epoxidation activity(44 h^(-1)) was observed over Nb based mesopor...Selective propylene epoxidation to propylene oxide(PO) with hydrogen peroxide(H_2O_2) was carried out in a catalytic semi-batch reactor.High propylene epoxidation activity(44 h^(-1)) was observed over Nb based mesoporous silicate materials Nb-TUD-1 under mild operating conditions.The physical and chemical properties of the Nb based silicates characterized using BET,FTIR,TPD,TEM and UV–Vis revealed that the site isolation and surface acidity are crucial for PO production.Catalyst synthesis methods were investigated for their effects on PO productivity,PO selectivity and H_2O_2 utilization efficiency.It is found that Nb-TUD-1 material synthesized by the sol–gel method is more active and selective than impregnated materials for liquid phase propylene epoxidation.Surface characterization confirms that thus synthesized Nb-TUD-1 catalysts have more Lewis acidity and less Bronsted acidity compared to the catalysts by impregnation.展开更多
基金the Ministry of Higher Education,Malaysia and Universiti Teknologi Malaysia(UTM) for the financial supports through Research University Grants (Q.J130000.2426.03G35 and Q.J130000.2526.10H54)
文摘Mesoporous Technische Universiteit Delft（TUD-1）-supported chromium oxide-doped titania（Cr-TiO2） was developed as a promising photocatalyst for phenol photodegradation under visible light irradiation.Low-angle X-ray diffraction and Fourier transform infrared spectroscopy results confirmed the amorphous and mesoporous silicate framework of TUD-1 in TUD-1-supported Cr-TiO2.The mesostructure of TUD-1 was further verified via N2 adsorption-desorption analysis,which showed a type-IV isotherm with a narrow average pore size distribution of 3.9 nm and high surface area of 490 m^2/g.Transmission electron microscopy analysis results indicated that TUD-1-supported Cr-TiO2 contained nanoparticles and porous channels.An increase in band gap energy was observed after loading Cr-TiO2 into TUD-1.Compared with that of unsupported Cr-TiO2,TUD-1-supported Cr-TiO2 showed higher photocatalytic activity for phenol degradation under visible light irradiation.The TUD-1 supported Cr-TiO2 photocatalyst with a Si/Ti molar ratio of 30 exhibited the highest photodegradation of phenol（82%） of the prepared samples.The photodegradation of phenol by the supported catalyst followed the Langmuir adsorption isotherm with first-order kinetics.
文摘Neodymium was incorporated into the three-dimensional mesoporous siliceous material TUD-1.In order to understand the chemical and morphological structure of the prepared material,several characterization techniques were performed.The characterization results show the formation of highly distributed isolated Nd3+ions incorporated in the silica matrix in tetrahedrally coordinated structure,moreover no aggregation of separate phase(s)was/were observed.The prepared material was investigated as an adsorbent for methyl green(MG)dye in aqueous solution as a model cationic dye.The results show higher adsorption capacity for Nd-TUD-1 by almost 24 times higher than the neat parent TUD-1 material and more than 100 times higher than bulky Nd_(2)O_(3)under neutral pH.The adsorption results were fitted perfectly with pseudo-second-order model.Moreover,the adsorption isotherms were perfectly fitted with Freundlich isotherm model which indicates the formation of a multilayer of the dye molecules onto the Nd-TUD-1 surface as a physisorption with endothermic nature.
基金Supported by the China Postdoctoral Science Foundation(2017 M612374)the Natural Science Foundation of Shandong Province(ZR2017BB007)+5 种基金the Postdoctoral Research Funding of Shandong Province(201703016)the Qingdao Postdoctoral Research Funding(BY20170210)the Fundamental Research Funding of Qingdao(17-1-1-67-jch,17-1-1-80-jch)the Fundamental Research Funds for the Central Universities(18CX02145A,17CX02017A)the New Faculty Start-up Funding from China University of Petroleum(YJ201601058)the Natural Science Foundation of China(21606254)
文摘Selective propylene epoxidation to propylene oxide(PO) with hydrogen peroxide(H_2O_2) was carried out in a catalytic semi-batch reactor.High propylene epoxidation activity(44 h^(-1)) was observed over Nb based mesoporous silicate materials Nb-TUD-1 under mild operating conditions.The physical and chemical properties of the Nb based silicates characterized using BET,FTIR,TPD,TEM and UV–Vis revealed that the site isolation and surface acidity are crucial for PO production.Catalyst synthesis methods were investigated for their effects on PO productivity,PO selectivity and H_2O_2 utilization efficiency.It is found that Nb-TUD-1 material synthesized by the sol–gel method is more active and selective than impregnated materials for liquid phase propylene epoxidation.Surface characterization confirms that thus synthesized Nb-TUD-1 catalysts have more Lewis acidity and less Bronsted acidity compared to the catalysts by impregnation.
