A mechanochemical redox reaction between KMnO4 and CoCl2 was developed to obtain a CoxMn1-xOy catalyst with a specific surface area of 479 m^2 g^-1,which was higher than that obtained using a co-precipitation(CP)metho...A mechanochemical redox reaction between KMnO4 and CoCl2 was developed to obtain a CoxMn1-xOy catalyst with a specific surface area of 479 m^2 g^-1,which was higher than that obtained using a co-precipitation(CP)method(34 m2 g^-1),sol-gel(SG)method(72 m^2 g^-1),or solution redox process(131 m^2 g^-1).During catalytic combustion,this CoxMn1-xOy catalyst exhibited better activity(T100 for propylene=~200℃)than the control catalysts obtained using the SG(325℃)or CP(450℃)methods.The mechanical action,mainly in the form of kinetic energy and frictional heating,may generate a high degree of interstitial porosity,while the redox reaction could contribute to good dispersion of cobalt and manganese species.Moreover,the as-prepared CoxMn1-xOy catalyst worked well in the presence of water vapor(H2O 4.2%,>60 h)or SO2(100 ppm)and at high temperature(400℃,>60 h).The structure MnO2·(CoOOH)2.93 was suggested for the current CoxMn1-xOy catalyst.This catalyst could be extended to the total oxidation of other typical hydrocarbons(T90=150°C for ethanol,T90=225°C for acetone,T90=250℃for toluene,T90=120℃for CO,and T90=540℃for CH4).Scale-up of the synthesis of CoxMn1-xOy catalyst(1 kg)can be achieved via ball milling,which may provide a potential strategy for real world catalysis.展开更多
High yields of CoFe204, NiFe204 and CdFe204 hierarchical porous ball-in-ball hollow spheres have been achieved using hydrothermal synthesis followed by calcination. The mechanism of formation is shown to involve an in...High yields of CoFe204, NiFe204 and CdFe204 hierarchical porous ball-in-ball hollow spheres have been achieved using hydrothermal synthesis followed by calcination. The mechanism of formation is shown to involve an in situ carbonaceous-template process. Hierarchical porous CoFe2O4 hollow spheres with different numbers of shells can be obtained by altering the synthesis conditions. The electrochemical properties of the resulting CoFe2O4 electrodes have been compared, using different binders. The as-obtained CoFe2O4 and NiFe2O4 have relatively high reversible discharge capacity and good rate retention performance which make them promising materials for use as anode materials in lithium ion batteries.展开更多
The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the re...The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the resultant potential applications for the degradation of volatile organic compounds(VOCs). The structure-activity relationships have been well-studied and used to facilitate design of the structure and composition of highly active catalysts. Recently, non-noble metal oxides with porous structures have been used as catalysts for deep oxidation of VOCs, such as aromatic hydrocarbons, aliphatic compounds, aldehydes, and alcohols, with comparable activities to their noble metal counterparts. This review summarizes the growing literature regarding the use of porous metal oxides for the catalytic removal of VOCs, with emphasis on design of the composition and structure and typical synthetic technologies.展开更多
文摘A mechanochemical redox reaction between KMnO4 and CoCl2 was developed to obtain a CoxMn1-xOy catalyst with a specific surface area of 479 m^2 g^-1,which was higher than that obtained using a co-precipitation(CP)method(34 m2 g^-1),sol-gel(SG)method(72 m^2 g^-1),or solution redox process(131 m^2 g^-1).During catalytic combustion,this CoxMn1-xOy catalyst exhibited better activity(T100 for propylene=~200℃)than the control catalysts obtained using the SG(325℃)or CP(450℃)methods.The mechanical action,mainly in the form of kinetic energy and frictional heating,may generate a high degree of interstitial porosity,while the redox reaction could contribute to good dispersion of cobalt and manganese species.Moreover,the as-prepared CoxMn1-xOy catalyst worked well in the presence of water vapor(H2O 4.2%,>60 h)or SO2(100 ppm)and at high temperature(400℃,>60 h).The structure MnO2·(CoOOH)2.93 was suggested for the current CoxMn1-xOy catalyst.This catalyst could be extended to the total oxidation of other typical hydrocarbons(T90=150°C for ethanol,T90=225°C for acetone,T90=250℃for toluene,T90=120℃for CO,and T90=540℃for CH4).Scale-up of the synthesis of CoxMn1-xOy catalyst(1 kg)can be achieved via ball milling,which may provide a potential strategy for real world catalysis.
文摘High yields of CoFe204, NiFe204 and CdFe204 hierarchical porous ball-in-ball hollow spheres have been achieved using hydrothermal synthesis followed by calcination. The mechanism of formation is shown to involve an in situ carbonaceous-template process. Hierarchical porous CoFe2O4 hollow spheres with different numbers of shells can be obtained by altering the synthesis conditions. The electrochemical properties of the resulting CoFe2O4 electrodes have been compared, using different binders. The as-obtained CoFe2O4 and NiFe2O4 have relatively high reversible discharge capacity and good rate retention performance which make them promising materials for use as anode materials in lithium ion batteries.
基金supported by the National High Technology Research and Development Program of China(2012AA062702)the strategic project of the Chinese Academy of Sciences(XDB05050000)
文摘The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the resultant potential applications for the degradation of volatile organic compounds(VOCs). The structure-activity relationships have been well-studied and used to facilitate design of the structure and composition of highly active catalysts. Recently, non-noble metal oxides with porous structures have been used as catalysts for deep oxidation of VOCs, such as aromatic hydrocarbons, aliphatic compounds, aldehydes, and alcohols, with comparable activities to their noble metal counterparts. This review summarizes the growing literature regarding the use of porous metal oxides for the catalytic removal of VOCs, with emphasis on design of the composition and structure and typical synthetic technologies.
