Vanadium-titanium-based catalysts are the most widely used industrial materials for NO_x removal from coal-fired power plants. Owing to their relatively poor low-temperature deNO_x activity, low thermal stability, ins...Vanadium-titanium-based catalysts are the most widely used industrial materials for NO_x removal from coal-fired power plants. Owing to their relatively poor low-temperature deNO_x activity, low thermal stability, insufficient Hg^0 oxidation activity, SO_2 oxidation, ammonia slip, and other disadvantages,modifications to traditional vanadium-titanium-based selective catalytic reduction（SCR）catalysts have been attempted by many researchers to promote their relevant performance. This article reviewed the research progress of modified vanadium-titanium-based SCR catalysts from seven aspects, namely,（1） improving low-temperature deNO_x efficiency,（2） enhancing thermal stability,（3） improving Hg^0 oxidation efficiency,（4） oxidizing slip ammonia,（5） reducing SO_2 oxidation,（6） increasing alkali resistance, and（7） others. Their catalytic performance and the influence mechanisms have been discussed in detail. These catalysts were also divided into different categories according to their modified components such as noble metals（e.g., silver, ruthenium）, transition metals（e.g., manganese, iron, copper, zirconium, etc.）, rare earth metals（e.g., cerium, praseodymium）,and other metal chlorides（e.g., calcium chloride, copper chloride） and non-metals（fluorine,sulfur, silicon, nitrogen, etc.）. The advantages and disadvantages of these catalysts were summarized.Based on previous studies and the author＇s point of view, doping the appropriate modified components is beneficial to further improve the overall performance of vanadium-titanium-based SCR catalysts. This has enormous development potential and is a promising way to realize the control of multiple pollutants on the basis of the existing flue gas treatment system.展开更多
La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for...La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for the first time for the photocatalytic removal of Hg~0 from a simulated flue gas under UV light irradiation.The results showed that the sample containing 6 wt.%La_(2)O_(3)and calcined at 500°C has the highest dispersion of the active sites,which was promoted by the strong interaction with the support(i.e.,the formation of Bi-O-La species).Since they are fully accessible on the surface,the material also exhibits excellent optical properties while the heterojunction formed in La_(2)O_(3)/Bi_(2)O_(3)promotes the separation and migration of photoelectron-hole pairs and thus Hg~0 oxidation efficiency is enhanced.The effects of the various factors(e.g.,the reaction temperature and composition of the simulated flue gas(i.e.,O_(2),NO,H_(2)O,and SO_(2)))on the efficiency of the Hg~0 photocatalytic oxidation were investigated.The results demonstrated that O_(2)and SO_(2)enhanced the efficiency of the reaction while the reaction temperature,NO,and H_(2)O had an inhibitory effect.展开更多
Antibody targeted delivery is an effective strategy to improve the diagnostic imaging outcome of nanoscale imaging agents in the focal areas. Dual targeting micelles encapsulating superparamagnetic iron oxide were pre...Antibody targeted delivery is an effective strategy to improve the diagnostic imaging outcome of nanoscale imaging agents in the focal areas. Dual targeting micelles encapsulating superparamagnetic iron oxide were prepared from the amphiphilic block copolymer poly（ethylene glycol）-poly（e-caprolactone） （PEG-b-PCL） with different targeting ligands cRGD and scFv-ErbB single chain antibody conjugated to the distal ends of PEG block. The breast cancer animal model was established by subcutaneous injecting the BT474 cells into the BALB/c-nu female nude mice and then employed to assess the potential of the dual ligand targeted magnetic micelles as a novel MRI contrast agent on a 1.5 T clinical MR/scanner. The T2 signal intensity of the tumor in animals receiving the dual ligand targeted magnetic micelles via tail vein decreased more significantly than the single ligand targeted and nontargeted magnetic micelles. These results indicate that the dual ligand targeted magnetic micelles, cRGD/scFv-ErbB-PEG-PCL-SPION, have great potential to act as a new type of effective nanoscale MRI contrast agent for early diagnosis of breast cancer.展开更多
In this study,a series of CuCl_(2)-modified MnO_(x)-CeO_(x)nanorods were synthesized for the oxidation of Hg^(0).The addition of CuCl_(2)resulted in an enhancement in the catalyst’s Hg^(0)oxidation ability,and Hg^(0)...In this study,a series of CuCl_(2)-modified MnO_(x)-CeO_(x)nanorods were synthesized for the oxidation of Hg^(0).The addition of CuCl_(2)resulted in an enhancement in the catalyst’s Hg^(0)oxidation ability,and Hg^(0)oxidation efficiency reached>97%from 150 to 250°C.In the MnO_(x)-CeO_(x)catalysts,Mn^(4+)played the role of the active species for Hg^(0)oxidization,but in the CuCl_(2)-doped catalysts Cl−also contributed to Hg^(0)oxidation,conferring the superior performance of these samples.The introduction of SO_(2) led to a decrease in the availability of Mn^(4+),and the Hg^(0)oxidation efficiency of MnO_(x)-CeO_(x)decreased from about 100%to about 78%.By contrast,CuCl_(2)-promoted samples maintained a Hg^(0)oxidation efficiency of about 100%during the SO_(2) deactivation cycle due to the high reactivity of Cl−.展开更多
Corrosion of iron-containing metals under sulfate-reducing conditions is an economically important problem.Microbial strains now known as Desulfovibrio vulgaris served as the model microbes in many of the foundational...Corrosion of iron-containing metals under sulfate-reducing conditions is an economically important problem.Microbial strains now known as Desulfovibrio vulgaris served as the model microbes in many of the foundational studies that developed existing models for the corrosion of iron-containing metals under sulfate-reducing conditions.Proposed mechanisms for corrosion by D.vulgaris include:(1)H2 consumption to accelerate the oxidation of Fe0 coupled to the reduction of protons to H2;(2)production of sulfide that combines with ferrous iron to form iron sulfide coatings that promote H2 production;(3)moribund cells release hydrogenases that catalyze Fe0 oxidation with the production of H2;(4)direct electron transfer from Fe0 to cells;and(5)flavins serving as an electron shuttle for electron transfer between Fe0 and cells.The demonstrated possibility of conducting transcriptomic and proteomic analysis of cells growing on metal surfaces suggests that similar studies on D.vulgaris corrosion biofilms can aid in identifying proteins that play an important role in corrosion.Tools for making targeted gene deletions in D.vulgaris are available for functional genetic studies.These approaches,coupled with instrumentation for the detection of low concentrations of H2,and proven techniques for evaluating putative electron shuttle function,are expected to make it possible to determine which of the proposed mechanisms for D.vulgaris corrosion are most important.展开更多
In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEC or EC） in a microbial fuel cell （MFC） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2....In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEC or EC） in a microbial fuel cell （MFC） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2. We examined the destruction of methylene blue （MB） and tetracycline. Fe^0/TiO2 was prepared using a chemical reduction-deposition method and coated onto an SS wire mesh （500 mesh） using a sol technique. The anode generates electricity using microbes （bio-anode）. Connected via wire and ohmic resistance, the system requires a short reaction time and operates at a low cost by effectively remowng 94% MB （initial concentration 20 mg·L^-1） and 83% TOC/TOCo under visible light illumination （50 W; 1.99 mW·cm^-2 for 120 rain, MFC-PEC）. The removal was similar even without light irradiation （MFC-EC）. The EEo of the MFC-PEC system was approximately 0.675 kWh·m^-3. order-l whereas that of the MFC-EC system was zero. The system was able to remove 70% COD in tetracycline solution （initial tetracycline concentration 100 mg·L^-1） after 120 min of visible light illumination; without light, the removal was 15% lower. The destruction of MB and tetracycline in both traditional photocatalysis and photoelectrocatalysis systems was notably low. The electron spinresonance spectroscopy （ESR） study demonstrated that. OH was formed under visible light, and. 02 was formed without light. The bio-electricity-activated O2 and ROS （reactive oxidizing species） generation by Fe^0/TiO2 effectively degraded the pollutants. This cathodic degradation improved the electricity generation by accepting and consuming more electrons from the bio-anode.展开更多
基金supported by the Science and Technology Plan Project of Hebei Province of China(16273703D)the Fundamental Research Funds for the Central Universities(2015ZD24,2017XS123)~~
文摘Vanadium-titanium-based catalysts are the most widely used industrial materials for NO_x removal from coal-fired power plants. Owing to their relatively poor low-temperature deNO_x activity, low thermal stability, insufficient Hg^0 oxidation activity, SO_2 oxidation, ammonia slip, and other disadvantages,modifications to traditional vanadium-titanium-based selective catalytic reduction（SCR）catalysts have been attempted by many researchers to promote their relevant performance. This article reviewed the research progress of modified vanadium-titanium-based SCR catalysts from seven aspects, namely,（1） improving low-temperature deNO_x efficiency,（2） enhancing thermal stability,（3） improving Hg^0 oxidation efficiency,（4） oxidizing slip ammonia,（5） reducing SO_2 oxidation,（6） increasing alkali resistance, and（7） others. Their catalytic performance and the influence mechanisms have been discussed in detail. These catalysts were also divided into different categories according to their modified components such as noble metals（e.g., silver, ruthenium）, transition metals（e.g., manganese, iron, copper, zirconium, etc.）, rare earth metals（e.g., cerium, praseodymium）,and other metal chlorides（e.g., calcium chloride, copper chloride） and non-metals（fluorine,sulfur, silicon, nitrogen, etc.）. The advantages and disadvantages of these catalysts were summarized.Based on previous studies and the author＇s point of view, doping the appropriate modified components is beneficial to further improve the overall performance of vanadium-titanium-based SCR catalysts. This has enormous development potential and is a promising way to realize the control of multiple pollutants on the basis of the existing flue gas treatment system.
基金supported by the National Key Research and Development Program of China(Nos.2017YFC0210500 and 2018YFC0213400)the National Natural Science Foundation of China(Nos.52070090 and 51868030)。
文摘La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for the first time for the photocatalytic removal of Hg~0 from a simulated flue gas under UV light irradiation.The results showed that the sample containing 6 wt.%La_(2)O_(3)and calcined at 500°C has the highest dispersion of the active sites,which was promoted by the strong interaction with the support(i.e.,the formation of Bi-O-La species).Since they are fully accessible on the surface,the material also exhibits excellent optical properties while the heterojunction formed in La_(2)O_(3)/Bi_(2)O_(3)promotes the separation and migration of photoelectron-hole pairs and thus Hg~0 oxidation efficiency is enhanced.The effects of the various factors(e.g.,the reaction temperature and composition of the simulated flue gas(i.e.,O_(2),NO,H_(2)O,and SO_(2)))on the efficiency of the Hg~0 photocatalytic oxidation were investigated.The results demonstrated that O_(2)and SO_(2)enhanced the efficiency of the reaction while the reaction temperature,NO,and H_(2)O had an inhibitory effect.
基金supported by the 863 Programs of China(No.2009AA03Z310)National Natural Science Foundation of China(Nos.21174166,30973419)+5 种基金the Ph.D.Programs Foundation of Ministry of Education of China(No.20100171110011)the Postdoctoral Foundation(No.201003370)Natural Science Foundation(Nos.9351027501000003,S2011020003140)S&T Programs of Guangdong Province(Nos.2010B031500011,2009B030803003,2009B030801107,2012B031800135)SYSU Projects for Promotion of Key and Emerging Interdisciplinary Researches(10ykjc18)Young Teachers(11lgpy44)
文摘Antibody targeted delivery is an effective strategy to improve the diagnostic imaging outcome of nanoscale imaging agents in the focal areas. Dual targeting micelles encapsulating superparamagnetic iron oxide were prepared from the amphiphilic block copolymer poly（ethylene glycol）-poly（e-caprolactone） （PEG-b-PCL） with different targeting ligands cRGD and scFv-ErbB single chain antibody conjugated to the distal ends of PEG block. The breast cancer animal model was established by subcutaneous injecting the BT474 cells into the BALB/c-nu female nude mice and then employed to assess the potential of the dual ligand targeted magnetic micelles as a novel MRI contrast agent on a 1.5 T clinical MR/scanner. The T2 signal intensity of the tumor in animals receiving the dual ligand targeted magnetic micelles via tail vein decreased more significantly than the single ligand targeted and nontargeted magnetic micelles. These results indicate that the dual ligand targeted magnetic micelles, cRGD/scFv-ErbB-PEG-PCL-SPION, have great potential to act as a new type of effective nanoscale MRI contrast agent for early diagnosis of breast cancer.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ22E060003)the General Research Projects of Zhejiang Provincial Department of Education in 2023(No.Y202353660)the Public Welfare Science and Technology Project of Ningbo City(No.202002N3105),China.
文摘In this study,a series of CuCl_(2)-modified MnO_(x)-CeO_(x)nanorods were synthesized for the oxidation of Hg^(0).The addition of CuCl_(2)resulted in an enhancement in the catalyst’s Hg^(0)oxidation ability,and Hg^(0)oxidation efficiency reached>97%from 150 to 250°C.In the MnO_(x)-CeO_(x)catalysts,Mn^(4+)played the role of the active species for Hg^(0)oxidization,but in the CuCl_(2)-doped catalysts Cl−also contributed to Hg^(0)oxidation,conferring the superior performance of these samples.The introduction of SO_(2) led to a decrease in the availability of Mn^(4+),and the Hg^(0)oxidation efficiency of MnO_(x)-CeO_(x)decreased from about 100%to about 78%.By contrast,CuCl_(2)-promoted samples maintained a Hg^(0)oxidation efficiency of about 100%during the SO_(2) deactivation cycle due to the high reactivity of Cl−.
文摘Corrosion of iron-containing metals under sulfate-reducing conditions is an economically important problem.Microbial strains now known as Desulfovibrio vulgaris served as the model microbes in many of the foundational studies that developed existing models for the corrosion of iron-containing metals under sulfate-reducing conditions.Proposed mechanisms for corrosion by D.vulgaris include:(1)H2 consumption to accelerate the oxidation of Fe0 coupled to the reduction of protons to H2;(2)production of sulfide that combines with ferrous iron to form iron sulfide coatings that promote H2 production;(3)moribund cells release hydrogenases that catalyze Fe0 oxidation with the production of H2;(4)direct electron transfer from Fe0 to cells;and(5)flavins serving as an electron shuttle for electron transfer between Fe0 and cells.The demonstrated possibility of conducting transcriptomic and proteomic analysis of cells growing on metal surfaces suggests that similar studies on D.vulgaris corrosion biofilms can aid in identifying proteins that play an important role in corrosion.Tools for making targeted gene deletions in D.vulgaris are available for functional genetic studies.These approaches,coupled with instrumentation for the detection of low concentrations of H2,and proven techniques for evaluating putative electron shuttle function,are expected to make it possible to determine which of the proposed mechanisms for D.vulgaris corrosion are most important.
文摘In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEC or EC） in a microbial fuel cell （MFC） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2. We examined the destruction of methylene blue （MB） and tetracycline. Fe^0/TiO2 was prepared using a chemical reduction-deposition method and coated onto an SS wire mesh （500 mesh） using a sol technique. The anode generates electricity using microbes （bio-anode）. Connected via wire and ohmic resistance, the system requires a short reaction time and operates at a low cost by effectively remowng 94% MB （initial concentration 20 mg·L^-1） and 83% TOC/TOCo under visible light illumination （50 W; 1.99 mW·cm^-2 for 120 rain, MFC-PEC）. The removal was similar even without light irradiation （MFC-EC）. The EEo of the MFC-PEC system was approximately 0.675 kWh·m^-3. order-l whereas that of the MFC-EC system was zero. The system was able to remove 70% COD in tetracycline solution （initial tetracycline concentration 100 mg·L^-1） after 120 min of visible light illumination; without light, the removal was 15% lower. The destruction of MB and tetracycline in both traditional photocatalysis and photoelectrocatalysis systems was notably low. The electron spinresonance spectroscopy （ESR） study demonstrated that. OH was formed under visible light, and. 02 was formed without light. The bio-electricity-activated O2 and ROS （reactive oxidizing species） generation by Fe^0/TiO2 effectively degraded the pollutants. This cathodic degradation improved the electricity generation by accepting and consuming more electrons from the bio-anode.
