POM-LDHs with the composition of MAI-XW11ZO39(M=Zn, Mg; X=P, Si; Z=Mn2+, Fe2+, Co2+, Ni2+, Cu2+) were synthesized, and their catalytic properties for oxidation of cyclohexene in the presence of dioxygen were studied. ...POM-LDHs with the composition of MAI-XW11ZO39(M=Zn, Mg; X=P, Si; Z=Mn2+, Fe2+, Co2+, Ni2+, Cu2+) were synthesized, and their catalytic properties for oxidation of cyclohexene in the presence of dioxygen were studied. The results obtained show that the oxidation of cyclohexene gives mainly α-H oxidation products, and the reaction activities greatly depend on the nature of the substituted transition metals in the POM pillars, i. e.,with different Z ions, the activity is in the order: Co2+～Cu2+～Mn2+》Ni2+～Fe2+. In addition, the central atom in the POM pillars has some effects on the oxidation of cyclohexene.The activity increases when P is used instead of Si. No obvious difference between the activities of ZnAl and MgAl layers were observed.展开更多
A series of novel photocatalysts, H3PW12O40-Y-TiO2 nanocomposites with different H3PW12O40 loading levels （10%-40%） were prepared by impregnation method. And the Y-TiO2 support, doped with yttrium, was synthesized v...A series of novel photocatalysts, H3PW12O40-Y-TiO2 nanocomposites with different H3PW12O40 loading levels （10%-40%） were prepared by impregnation method. And the Y-TiO2 support, doped with yttrium, was synthesized via sol-gel technique. The prepared catalysts were characterized by Fourier transform infrared spectroscopy （FT-IR）, powder X-ray diffraction （XRD）, nitrogen adsorption-desorption analysis and scanning electron microscopy （SEM）. The processes allowed obtaining Keggin structure and crystallized anatase with large BET surface area as well as uniform distribution. The effects of H3PW12O40 loadings, catalyst dose, initial pH and concentration of dye solution on the degradation kinetics of methyl orange under UV light （λ≥365 nm） were discussed. Kinetics studies showed that the photocatalytic degradation of methyl orange fitted the apparent first-order reaction. Methyl orange was totally degraded in 21 min under optimum conditions： 20% loading, 0.03 g dose and pH 1.0. The catalyst was stable and easily to be separated from reaction system for recovery.展开更多
The investigation photocatalytic degradation of three azo dyes solution(Acid Mordant Navy Blue RRN,Acid Mordant Black PV,Acid Mordant Brown RH) under UV light irradiation using the polyoxometalates as catalyst was rep...The investigation photocatalytic degradation of three azo dyes solution(Acid Mordant Navy Blue RRN,Acid Mordant Black PV,Acid Mordant Brown RH) under UV light irradiation using the polyoxometalates as catalyst was reported in this article.The research results showed that the photocatalytic activity of Keggin catalyst is higher than that of Dawson,and the catalyst α-H4SiW12O40 had the best efficiency to the photocatalytic decoloration of RRN.In 350 mg·L-1(30 mL) RRN solution,the optimum reaction condition was as follow:the amount of catalyst α-H4SiW12O40 is 75 μmol·L-1,V(methanol)=3.0 mL,pH=3.0.Under the above condition,the decolorization rate of RRN at 40 minutes comes up to 98.66%.展开更多
Extractive oxidation, wherein aromatic sulfur- containing compounds are extracted and subsequently oxidized to their corresponding sulfones, has proven to be one of the most effective desulfurization methods for produ...Extractive oxidation, wherein aromatic sulfur- containing compounds are extracted and subsequently oxidized to their corresponding sulfones, has proven to be one of the most effective desulfurization methods for producing ultra-low sulfur content fuels. As non-volatile and highly designable solvents, ionic liquids （ILs） have attracted considerable attention for the oxidative desulfur- ization of fuels. In this review, we systematically discuss the utility of ILs in catalytic and extractive oxidation, including their role as extractant, catalyst, or both. We also discuss the challenges facing the use of ILs in this regard, including their relatively high cost and excessive viscosity, as well as their efficiency and stability as catalyst.展开更多
Proteolytic degradation of amyloid-β （Aβ） aggregates and clearance of Aβ- induced reactive oxygen species （ROS） have received significant attention for the treatment of Alzheimer＇s disease （AD）. However, it ...Proteolytic degradation of amyloid-β （Aβ） aggregates and clearance of Aβ- induced reactive oxygen species （ROS） have received significant attention for the treatment of Alzheimer＇s disease （AD）. However, it is difficult, and often unfeasible, to directly upregulate or transport intraceUular native enzymes. More importantly, penetration of the blood-brain barrier （BBB） has presented a major impediment. Herein, we report on the rational design of a polyoxometalate- based nanozyme with both protease-like activity for depleting A~ aggregates, and superoxide dismutase （SOD）-like activity for scavenging A[3-mediated ROS. Furthermore, this nanozyme acts as a metal chelator to remove Cu from Cu-induced Aβ oligomers. More intriguingly, the nanozyme can cross the BBB and exhibits low toxicity. This work provides new insights into the design and synthesis of inorganic nanozymes as multifunctional therapeutic agents in the treatment of AD.展开更多
With the increasing concerns to energy shortage and environmental problems in modern society,the development of cheap,clean,and sustainable energy alternatives has been attracting tremendous attention globally.Among v...With the increasing concerns to energy shortage and environmental problems in modern society,the development of cheap,clean,and sustainable energy alternatives has been attracting tremendous attention globally.Among various strategies of renewable energy exploration,solar-driven water splitting into its compositional elements H2 and O2 is an ideal approach to convert and store renewable solar energy into chemical bonds.In recent few decades,as an emerging new type of catalysts,polyoxometalates(POMs)have been widely utilized for water splitting due to their versatile synthetic methodology and highly tunable physicochemical and photochemical properties.This critical review addresses the research advances of light-driven hydrogen evolution using polyoxometalate-based catalysts,including plenary POMs,transition-metal-substituted POMs,POM@MOF composites,and POM-semiconductor hybrids,under UV,near UV and visible light irradiation.In addition,the catalytic mechanism for each reaction system has been thoroughly discussed and summarized.Finally,a comprehensive outlook of this research area is also prospected.展开更多
文摘POM-LDHs with the composition of MAI-XW11ZO39(M=Zn, Mg; X=P, Si; Z=Mn2+, Fe2+, Co2+, Ni2+, Cu2+) were synthesized, and their catalytic properties for oxidation of cyclohexene in the presence of dioxygen were studied. The results obtained show that the oxidation of cyclohexene gives mainly α-H oxidation products, and the reaction activities greatly depend on the nature of the substituted transition metals in the POM pillars, i. e.,with different Z ions, the activity is in the order: Co2+～Cu2+～Mn2+》Ni2+～Fe2+. In addition, the central atom in the POM pillars has some effects on the oxidation of cyclohexene.The activity increases when P is used instead of Si. No obvious difference between the activities of ZnAl and MgAl layers were observed.
基金Project supported by Institution of Chemical Materials, China Academy of Engineering Physics
文摘A series of novel photocatalysts, H3PW12O40-Y-TiO2 nanocomposites with different H3PW12O40 loading levels （10%-40%） were prepared by impregnation method. And the Y-TiO2 support, doped with yttrium, was synthesized via sol-gel technique. The prepared catalysts were characterized by Fourier transform infrared spectroscopy （FT-IR）, powder X-ray diffraction （XRD）, nitrogen adsorption-desorption analysis and scanning electron microscopy （SEM）. The processes allowed obtaining Keggin structure and crystallized anatase with large BET surface area as well as uniform distribution. The effects of H3PW12O40 loadings, catalyst dose, initial pH and concentration of dye solution on the degradation kinetics of methyl orange under UV light （λ≥365 nm） were discussed. Kinetics studies showed that the photocatalytic degradation of methyl orange fitted the apparent first-order reaction. Methyl orange was totally degraded in 21 min under optimum conditions： 20% loading, 0.03 g dose and pH 1.0. The catalyst was stable and easily to be separated from reaction system for recovery.
文摘The investigation photocatalytic degradation of three azo dyes solution(Acid Mordant Navy Blue RRN,Acid Mordant Black PV,Acid Mordant Brown RH) under UV light irradiation using the polyoxometalates as catalyst was reported in this article.The research results showed that the photocatalytic activity of Keggin catalyst is higher than that of Dawson,and the catalyst α-H4SiW12O40 had the best efficiency to the photocatalytic decoloration of RRN.In 350 mg·L-1(30 mL) RRN solution,the optimum reaction condition was as follow:the amount of catalyst α-H4SiW12O40 is 75 μmol·L-1,V(methanol)=3.0 mL,pH=3.0.Under the above condition,the decolorization rate of RRN at 40 minutes comes up to 98.66%.
文摘Extractive oxidation, wherein aromatic sulfur- containing compounds are extracted and subsequently oxidized to their corresponding sulfones, has proven to be one of the most effective desulfurization methods for producing ultra-low sulfur content fuels. As non-volatile and highly designable solvents, ionic liquids （ILs） have attracted considerable attention for the oxidative desulfur- ization of fuels. In this review, we systematically discuss the utility of ILs in catalytic and extractive oxidation, including their role as extractant, catalyst, or both. We also discuss the challenges facing the use of ILs in this regard, including their relatively high cost and excessive viscosity, as well as their efficiency and stability as catalyst.
基金Financial support was provided by the National Basic Research Program of China （973 Project） （Nos. 2011CB936004 and 2012CB720602） and the National Natural Science Foundation of China （Nos. 21210002, 21431007, 21402183, and 21533008）.
文摘Proteolytic degradation of amyloid-β （Aβ） aggregates and clearance of Aβ- induced reactive oxygen species （ROS） have received significant attention for the treatment of Alzheimer＇s disease （AD）. However, it is difficult, and often unfeasible, to directly upregulate or transport intraceUular native enzymes. More importantly, penetration of the blood-brain barrier （BBB） has presented a major impediment. Herein, we report on the rational design of a polyoxometalate- based nanozyme with both protease-like activity for depleting A~ aggregates, and superoxide dismutase （SOD）-like activity for scavenging A[3-mediated ROS. Furthermore, this nanozyme acts as a metal chelator to remove Cu from Cu-induced Aβ oligomers. More intriguingly, the nanozyme can cross the BBB and exhibits low toxicity. This work provides new insights into the design and synthesis of inorganic nanozymes as multifunctional therapeutic agents in the treatment of AD.
文摘With the increasing concerns to energy shortage and environmental problems in modern society,the development of cheap,clean,and sustainable energy alternatives has been attracting tremendous attention globally.Among various strategies of renewable energy exploration,solar-driven water splitting into its compositional elements H2 and O2 is an ideal approach to convert and store renewable solar energy into chemical bonds.In recent few decades,as an emerging new type of catalysts,polyoxometalates(POMs)have been widely utilized for water splitting due to their versatile synthetic methodology and highly tunable physicochemical and photochemical properties.This critical review addresses the research advances of light-driven hydrogen evolution using polyoxometalate-based catalysts,including plenary POMs,transition-metal-substituted POMs,POM@MOF composites,and POM-semiconductor hybrids,under UV,near UV and visible light irradiation.In addition,the catalytic mechanism for each reaction system has been thoroughly discussed and summarized.Finally,a comprehensive outlook of this research area is also prospected.
