A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-Ir...A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-IrO_2-SnO_2/Ti anodes. The influences of electric current density, inlet liquid circulation flowrate, high gravity factor, sodium chloride concentration,and initial pH value on phenol degradation efficiency were investigated, with the optimal operating conditions determined. The results showed that under the optimal operating conditions covering a current density of 35 mA/cm^2, an inlet liquid circulation flowrate of 48 L/h, a high gravity factor of 20, a sodium chloride concentration of 8.5 g/L, an initial pH value of 6.5, a reaction time of 100 min, and an initial phenol concentration of 500 mg/L, the efficiency for removal of phenol reached 99.7%, which was improved by 10.4% as compared to that achieved in the normal gravity field. The tendency regarding the change in efficiency for removal of phenol, total organic carbon(TOC), and chemical oxygen demand(COD)over time was studied. The intermediates and degradation pathway of phenol were deduced by high performance liquid chromatography(HPLC).展开更多
The performance of BaC12-TiO2-SnO2 composite catalysts in oxidative coupling of methane reaction has been investigated. A series of BaC12-TiO2, BaC1E-SnO2, TiO2-SnO2, and BaC12-TiO2-SnO2 catalysts were prepared, and c...The performance of BaC12-TiO2-SnO2 composite catalysts in oxidative coupling of methane reaction has been investigated. A series of BaC12-TiO2, BaC1E-SnO2, TiO2-SnO2, and BaC12-TiO2-SnO2 catalysts were prepared, and characterized by BET, XRD, XPS, CO2-TPD and H2-TPR, respectively. The synergistic effect among BaC12, SnO2 and TiO2 compositions enhances the catalytic performance. The best C2 selectivity and ethylene yield are obtained on the catalyst with the equal molar amount of the three compositions (BaC12 : TiO2 : SnO2 molar ratio of 1 : 1 : 1). The optimal reaction conditions are as follows: 800 ℃, 44 mL.min-1 for methane, 22 mL.min-1 for oxygen and a space velocity of 5000 mL-h-1 .g-1, and the C2H4 yield over the catalyst is 20.1% with the CH4 conversion of 43.8% and C2 selectivity of 53.3%.展开更多
Nanometer RuO2-SnO2 was synthesized by the citrate-gel method using RuCl3, SnCl4 as cation sources, citric acid as complexing agent and anhydrous ethanol as solvent. The structures of the derived powders were characte...Nanometer RuO2-SnO2 was synthesized by the citrate-gel method using RuCl3, SnCl4 as cation sources, citric acid as complexing agent and anhydrous ethanol as solvent. The structures of the derived powders were characterized by thermogravimetric and differential thermal analysis, X-ray diffraction, transmission electron microscope, and Brunauer-Emmett-Teller surface area measurement. The pure, fine and amorphous powders was obtained at 160℃. The materials calcined at above 400 ℃ were composed of rutile-type oxide phases having particle sizes of fairly narrow distribution and good thermal resistant properties. By adding SnO2 to RuO2, the Ru metallic phase can be effectively controlled under a traditional temperature of preparation for dimensional stable anode.展开更多
Ru Sn binary oxide is one of the most frequently used anode coating material in electrochemical industry, but its composition distribution and microstructure are not homogeneous, so the nanoscale RuO 2 SnO 2 binary ox...Ru Sn binary oxide is one of the most frequently used anode coating material in electrochemical industry, but its composition distribution and microstructure are not homogeneous, so the nanoscale RuO 2 SnO 2 binary oxide was prepared for improvement by a sol gel technique. The morphology, microstructure, crystal structure and other properties of the new oxide were studied by EPMA, DTA,XRD,TEM, and electrochemical analysis. The results showed that the Ru Sn oxide nanomaterial has excellent electrocatalytical properties.展开更多
V2O5/WO3‐TiO2 and V2O5/WO3‐TiO2‐SiO2 catalysts were prepared by a wetness impregnation method, and both the catalysts were hydrothermally aged at 750℃ in 10 vol%H2O/air for 24 h. The catalysts were evaluated for N...V2O5/WO3‐TiO2 and V2O5/WO3‐TiO2‐SiO2 catalysts were prepared by a wetness impregnation method, and both the catalysts were hydrothermally aged at 750℃ in 10 vol%H2O/air for 24 h. The catalysts were evaluated for NOx conversion using NH3 as the reductant. Hydrothermal ageing decreased the NOx conversion of V2O5/WO3‐TiO2 catalyst severely over the entire measured tem‐perature range. Interestingly, the NH3‐SCR activity of the silica‐modified catalyst at 220–480℃ is enhanced after ageing. The catalysts were characterized by X‐ray diffraction, nitrogen adsorption, X‐ray fluorescence, Raman spectroscopy, H2 temperature‐programmed reduction, and NH3 temper‐ature‐programmed desorption. The addition of silica inhibited the phase transition from anatase to rutile titania, growth of TiO2 crystallite size and shrinkage of catalyst surface area. Consequently, the vanadia species remained highly dispersed and the hydrothermal stability of the V2O5/WO3‐TiO2 catalyst was significantly improved.展开更多
In this work we prepared several CeO2-TiO2 catalysts for the NH3-SCR reactionusing co-precipitation with assistance of microwave irradiation.The catalytic NH3-SCR activities over CeO2-TiO2 catalysts at low temperature...In this work we prepared several CeO2-TiO2 catalysts for the NH3-SCR reactionusing co-precipitation with assistance of microwave irradiation.The catalytic NH3-SCR activities over CeO2-TiO2 catalysts at low temperatures are largely enhanced by the treatment of microwave irradiation,the operation temperature window is also broadened.For better understanding the promotion mechanism,the catalyst prepared by conventional co-precipitation with and without microwave irradiation treatment was characterized with H2-TPR,NH3-TPD,XPS,XRD and BET.Microwave irradiation treatment accelerates the crystallite rate of CeO2-TiO2 catalysts,and greatly enlarges their surface area by adjusting their microstructures.The resistance to SO2 and H2O is also improved via regulating the hierarchical pore structure by the microwave irradiation.Microwave irradiation treatment can also improve the redox property and increase the acid sites over the catalyst surfaces.The result of in situ DRIFTS suggests that the microwave irradiation treatment generates more Br?nsted acid sites on CeO2-TiO2-2 h catalyst,helpful in SCR reactions.XPS results show that after microwave irradiation on the CeO2-TiO2 catalysts,the surface demonstrates an elevated concentration of chemisorbed oxygen,consequently leading to better oxidation of NO to NO2.Additionally,the molar ratio of Ce3+/Ce4+has been elevated after being treated by microwave irradiation,a vital factor in enhancing the NH3-SCR activities.展开更多
基金financially supported by the Nature Science Foundation of China (Grant No.U1610106)the Nature Science Foundation of China (Grant No.21703208)
摘要A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-IrO_2-SnO_2/Ti anodes. The influences of electric current density, inlet liquid circulation flowrate, high gravity factor, sodium chloride concentration,and initial pH value on phenol degradation efficiency were investigated, with the optimal operating conditions determined. The results showed that under the optimal operating conditions covering a current density of 35 mA/cm^2, an inlet liquid circulation flowrate of 48 L/h, a high gravity factor of 20, a sodium chloride concentration of 8.5 g/L, an initial pH value of 6.5, a reaction time of 100 min, and an initial phenol concentration of 500 mg/L, the efficiency for removal of phenol reached 99.7%, which was improved by 10.4% as compared to that achieved in the normal gravity field. The tendency regarding the change in efficiency for removal of phenol, total organic carbon(TOC), and chemical oxygen demand(COD)over time was studied. The intermediates and degradation pathway of phenol were deduced by high performance liquid chromatography(HPLC).
摘要The performance of BaC12-TiO2-SnO2 composite catalysts in oxidative coupling of methane reaction has been investigated. A series of BaC12-TiO2, BaC1E-SnO2, TiO2-SnO2, and BaC12-TiO2-SnO2 catalysts were prepared, and characterized by BET, XRD, XPS, CO2-TPD and H2-TPR, respectively. The synergistic effect among BaC12, SnO2 and TiO2 compositions enhances the catalytic performance. The best C2 selectivity and ethylene yield are obtained on the catalyst with the equal molar amount of the three compositions (BaC12 : TiO2 : SnO2 molar ratio of 1 : 1 : 1). The optimal reaction conditions are as follows: 800 ℃, 44 mL.min-1 for methane, 22 mL.min-1 for oxygen and a space velocity of 5000 mL-h-1 .g-1, and the C2H4 yield over the catalyst is 20.1% with the CH4 conversion of 43.8% and C2 selectivity of 53.3%.
基金the National Natural Science Foundation of China(No.50472002)the Science & Technical Development Foundation of Fuzhou University(No.2006-XQ-02)the Science & Technology Bureau Foundation of Fujian Province(JB05013)
摘要Nanometer RuO2-SnO2 was synthesized by the citrate-gel method using RuCl3, SnCl4 as cation sources, citric acid as complexing agent and anhydrous ethanol as solvent. The structures of the derived powders were characterized by thermogravimetric and differential thermal analysis, X-ray diffraction, transmission electron microscope, and Brunauer-Emmett-Teller surface area measurement. The pure, fine and amorphous powders was obtained at 160℃. The materials calcined at above 400 ℃ were composed of rutile-type oxide phases having particle sizes of fairly narrow distribution and good thermal resistant properties. By adding SnO2 to RuO2, the Ru metallic phase can be effectively controlled under a traditional temperature of preparation for dimensional stable anode.
摘要Ru Sn binary oxide is one of the most frequently used anode coating material in electrochemical industry, but its composition distribution and microstructure are not homogeneous, so the nanoscale RuO 2 SnO 2 binary oxide was prepared for improvement by a sol gel technique. The morphology, microstructure, crystal structure and other properties of the new oxide were studied by EPMA, DTA,XRD,TEM, and electrochemical analysis. The results showed that the Ru Sn oxide nanomaterial has excellent electrocatalytical properties.
基金supported by the National Natural Science Foundation of China (51372137)the National High Technology Research and Development Program of China (863 Program,2015AA034603)~~
摘要V2O5/WO3‐TiO2 and V2O5/WO3‐TiO2‐SiO2 catalysts were prepared by a wetness impregnation method, and both the catalysts were hydrothermally aged at 750℃ in 10 vol%H2O/air for 24 h. The catalysts were evaluated for NOx conversion using NH3 as the reductant. Hydrothermal ageing decreased the NOx conversion of V2O5/WO3‐TiO2 catalyst severely over the entire measured tem‐perature range. Interestingly, the NH3‐SCR activity of the silica‐modified catalyst at 220–480℃ is enhanced after ageing. The catalysts were characterized by X‐ray diffraction, nitrogen adsorption, X‐ray fluorescence, Raman spectroscopy, H2 temperature‐programmed reduction, and NH3 temper‐ature‐programmed desorption. The addition of silica inhibited the phase transition from anatase to rutile titania, growth of TiO2 crystallite size and shrinkage of catalyst surface area. Consequently, the vanadia species remained highly dispersed and the hydrothermal stability of the V2O5/WO3‐TiO2 catalyst was significantly improved.
基金Project supported by the National Natural Science Foundation of China(21577005)the National Key Research and Development Program of China(2016YFB0600400)
摘要In this work we prepared several CeO2-TiO2 catalysts for the NH3-SCR reactionusing co-precipitation with assistance of microwave irradiation.The catalytic NH3-SCR activities over CeO2-TiO2 catalysts at low temperatures are largely enhanced by the treatment of microwave irradiation,the operation temperature window is also broadened.For better understanding the promotion mechanism,the catalyst prepared by conventional co-precipitation with and without microwave irradiation treatment was characterized with H2-TPR,NH3-TPD,XPS,XRD and BET.Microwave irradiation treatment accelerates the crystallite rate of CeO2-TiO2 catalysts,and greatly enlarges their surface area by adjusting their microstructures.The resistance to SO2 and H2O is also improved via regulating the hierarchical pore structure by the microwave irradiation.Microwave irradiation treatment can also improve the redox property and increase the acid sites over the catalyst surfaces.The result of in situ DRIFTS suggests that the microwave irradiation treatment generates more Br?nsted acid sites on CeO2-TiO2-2 h catalyst,helpful in SCR reactions.XPS results show that after microwave irradiation on the CeO2-TiO2 catalysts,the surface demonstrates an elevated concentration of chemisorbed oxygen,consequently leading to better oxidation of NO to NO2.Additionally,the molar ratio of Ce3+/Ce4+has been elevated after being treated by microwave irradiation,a vital factor in enhancing the NH3-SCR activities.