Highly active calcium chloride（CaCl2） doped Zn-Co^Ⅲdouble metal-cyanide（Ca-DMC） catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield（54 kg polymer/g catalyst） at relative low temperatur...Highly active calcium chloride（CaCl2） doped Zn-Co^Ⅲdouble metal-cyanide（Ca-DMC） catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield（54 kg polymer/g catalyst） at relative low temperature（80-115℃） toward ringopening polymerization（ROP） of propylene oxide（PO） than did DMC catalysts without modification.展开更多
We present a one-pot colloidal synthesis method for producing monodisperse multi-metal(Co,Mn,and Fe)spinel nanocrystals(NCs),including nanocubes,nano-octahedra,and concave nanocubes.This study explores the mechanism o...We present a one-pot colloidal synthesis method for producing monodisperse multi-metal(Co,Mn,and Fe)spinel nanocrystals(NCs),including nanocubes,nano-octahedra,and concave nanocubes.This study explores the mechanism of morphology control,showcasing the pivotal roles of metal precursors and capping ligands in determining the exposed crystal planes on the NC surface.The cubic spinel NCs,terminated with exclusive{100}-facets,demonstrate superior electrocatalytic activity for the oxygen reduction reaction(ORR)in alkaline media compared to their octahedral and concave cubic counterparts.Specifically,at 0.85 V,(CoMn)Fe_(2)O_(4) spinel oxide nanocubes achieve a high mass activity of 23.9 A/g and exhibit excellent stability,highlighting the promising ORR performance associated with{100}-facets of multi-metal spinel oxides over other low-index and high-index facets.Motivated by exploring the correlation between ORR performance and surface atom arrangement(active sites),surface element composition,as well as other factors,this study introduces a prospective approach for shapecontrolled synthesis of advanced spinel oxide NCs.It underscores the significance of catalyst shape control and suggests potential applications as nonprecious metal ORR electrocatalysts.展开更多
The extraction process of gold and silver from the gold clay ore containing arsenic and manganese was investigated.With the conventional technique,the leaching rates of gold and silver are 78.23%and 49.02%,respectivel...The extraction process of gold and silver from the gold clay ore containing arsenic and manganese was investigated.With the conventional technique,the leaching rates of gold and silver are 78.23%and 49.02%,respectively.To eliminate the negative effects of arsenic and manganese on cyanidation and increase the gold and silver leaching rates,a novel catalyst was added.The content of the catalyst used in the process was 8 g per 500 g org sample,the sample size was 60μm and the pH value was kept between 10 and 11.Leaching with the catalyst for 3-5 h under certain conditions,the gold leaching rate increased to over 90%and the silver leaching rate increased to 80%-90%.The catalyst can effectively liberate gold and silver from the enclosure of arsenic and manganese and the industrial experiment has great significance to the development and utilization of the gold clay ore containing arsenic and manganese.展开更多
The effects of organic ethers such as diethyl ether, ethylene glycol diethyl ether and diethyl glycol diethyl ether on the structure of double metal cyanide complex catalyst and the structural changes of such catalyst...The effects of organic ethers such as diethyl ether, ethylene glycol diethyl ether and diethyl glycol diethyl ether on the structure of double metal cyanide complex catalyst and the structural changes of such catalyst in the process of propylene oxide polymerization were investigated by EXAFS. The results show that Co in all DMC catalysts is still coordinated by six cyanogens, while Zn is coordinated by O atom in organic complex. The more numerous the number of the ether bond, the higher the coordination numbers of O to Zn ion, the more active the catalyst we make. Five or six O atoms coordinated Zn ion may be the real active center in the process of propylene oxide polymerization.展开更多
基金the financial supports of the National Science Foundation of the People's Republic of China(No.20704034)Provincial Natural Science Foundation of Zhejiang(No.Y4090047)
文摘Highly active calcium chloride（CaCl2） doped Zn-Co^Ⅲdouble metal-cyanide（Ca-DMC） catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield（54 kg polymer/g catalyst） at relative low temperature（80-115℃） toward ringopening polymerization（ROP） of propylene oxide（PO） than did DMC catalysts without modification.
基金National Science Foundation,Division of Materials Research,Grant/Award Numbers:DMR-1808383,DMR-2347030,DMR-1905422Department of Energy,Basic Energy Sciences,Grant/Award Number:DE-SC0012704。
文摘We present a one-pot colloidal synthesis method for producing monodisperse multi-metal(Co,Mn,and Fe)spinel nanocrystals(NCs),including nanocubes,nano-octahedra,and concave nanocubes.This study explores the mechanism of morphology control,showcasing the pivotal roles of metal precursors and capping ligands in determining the exposed crystal planes on the NC surface.The cubic spinel NCs,terminated with exclusive{100}-facets,demonstrate superior electrocatalytic activity for the oxygen reduction reaction(ORR)in alkaline media compared to their octahedral and concave cubic counterparts.Specifically,at 0.85 V,(CoMn)Fe_(2)O_(4) spinel oxide nanocubes achieve a high mass activity of 23.9 A/g and exhibit excellent stability,highlighting the promising ORR performance associated with{100}-facets of multi-metal spinel oxides over other low-index and high-index facets.Motivated by exploring the correlation between ORR performance and surface atom arrangement(active sites),surface element composition,as well as other factors,this study introduces a prospective approach for shapecontrolled synthesis of advanced spinel oxide NCs.It underscores the significance of catalyst shape control and suggests potential applications as nonprecious metal ORR electrocatalysts.
基金supported by the National Natural Science Foundation of China(No.20877036) the Natural Science Foundation of Shaanxi Province,China(No.2006Z06)
文摘The extraction process of gold and silver from the gold clay ore containing arsenic and manganese was investigated.With the conventional technique,the leaching rates of gold and silver are 78.23%and 49.02%,respectively.To eliminate the negative effects of arsenic and manganese on cyanidation and increase the gold and silver leaching rates,a novel catalyst was added.The content of the catalyst used in the process was 8 g per 500 g org sample,the sample size was 60μm and the pH value was kept between 10 and 11.Leaching with the catalyst for 3-5 h under certain conditions,the gold leaching rate increased to over 90%and the silver leaching rate increased to 80%-90%.The catalyst can effectively liberate gold and silver from the enclosure of arsenic and manganese and the industrial experiment has great significance to the development and utilization of the gold clay ore containing arsenic and manganese.
文摘The effects of organic ethers such as diethyl ether, ethylene glycol diethyl ether and diethyl glycol diethyl ether on the structure of double metal cyanide complex catalyst and the structural changes of such catalyst in the process of propylene oxide polymerization were investigated by EXAFS. The results show that Co in all DMC catalysts is still coordinated by six cyanogens, while Zn is coordinated by O atom in organic complex. The more numerous the number of the ether bond, the higher the coordination numbers of O to Zn ion, the more active the catalyst we make. Five or six O atoms coordinated Zn ion may be the real active center in the process of propylene oxide polymerization.
