The general characteristics of the active center of the catalysts（including zinc-cobalt（III） double metal cyanide complex [Zn-Co（Ⅲ） DMCC]） for the copolymerization reaction of carbon dioxide（CO2） with epoxide...The general characteristics of the active center of the catalysts（including zinc-cobalt（III） double metal cyanide complex [Zn-Co（Ⅲ） DMCC]） for the copolymerization reaction of carbon dioxide（CO2） with epoxide are summarized. By comparing the active center, catalytic performance of the Zn-Co（Ⅲ） DMCC（and other catalysts） with HCAII enzyme in the organism for activating CO2（COS and CS2）, we proposed that the metal-hydroxide bond（M-OH）, which is the real catalytic center of human carbonic anhydride Ⅱ（HCAⅡ）, is also the catalytic（initiating） center for the copolymerization. It accelerates the copolymerization and forms a closed catalytic cycle through the chain transfer reaction to water（and thus strictly meets the definition of the catalyst）. In addition, the metal-hydroxide bond catalysis could well explain the oxygen/sulfur exchange reaction（O/S ER） in metal（Zn, Cr）-catalyzed copolymerization of COS（and CS2） with epoxides. Therefore, it is very promising to learn from HCAⅡ enzyme to develop biomimetic catalyst for highly active CO2/epoxide copolymerization in a well-controlled manner under mild conditions.展开更多
Direct growth of redox-active noble metals and rational design of multifunctional electrochemical active materials play crucial roles in developing novel electrode materials for energy storage devices.In this regard,s...Direct growth of redox-active noble metals and rational design of multifunctional electrochemical active materials play crucial roles in developing novel electrode materials for energy storage devices.In this regard,silver(Ag)has attracted great attention in the design of efficient electrodes.Inspired by the house/building process,which means electing the right land,it lays a strong foundation and building essential columns for a complex structure.Herein,we report the construction of multifaceted heterostructure cobalt-iron hydroxide(CFOH)nanowires(NWs)@nickel cobalt manganese hydroxides and/or hydrate(NCMOH)nanosheets(NSs)on the Ag-deposited nickel foam and carbon cloth(i.e.,Ag/NF and Ag/CC)substrates.Moreover,the formation and charge storage mechanism of Ag are described,and these contribute to good conductive and redox chemistry features.The switching architectural integrity of metal and redox materials on metallic frames may significantly boost charge storage and rate performance with noticeable drop in resistance.The as-fabricated Ag@CFOH@NCMOH/NF electrode delivered superior areal capacity value of 2081.9μA h cm^(-2)at 5 mA cm^(-2).Moreover,as-assembled hybrid cell based on NF(HC/NF)device exhibited remarkable areal capacity value of 1.82 mA h cm^(-2)at 5 mA cm^(-2)with excellent rate capability of 74.77%even at 70 mA cm^(-2)Furthermore,HC/NF device achieved maximum energy and power densities of 1.39 mW h cm^(-2)and 42.35 mW cm^(-2),respectively.To verify practical applicability,both devices were also tested to serve as a self-charging station for various portable electronic devices.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21474083)the Distinguished Young Investigator Fund of Zhejiang Province(No.LR16B040001)
文摘The general characteristics of the active center of the catalysts（including zinc-cobalt（III） double metal cyanide complex [Zn-Co（Ⅲ） DMCC]） for the copolymerization reaction of carbon dioxide（CO2） with epoxide are summarized. By comparing the active center, catalytic performance of the Zn-Co（Ⅲ） DMCC（and other catalysts） with HCAII enzyme in the organism for activating CO2（COS and CS2）, we proposed that the metal-hydroxide bond（M-OH）, which is the real catalytic center of human carbonic anhydride Ⅱ（HCAⅡ）, is also the catalytic（initiating） center for the copolymerization. It accelerates the copolymerization and forms a closed catalytic cycle through the chain transfer reaction to water（and thus strictly meets the definition of the catalyst）. In addition, the metal-hydroxide bond catalysis could well explain the oxygen/sulfur exchange reaction（O/S ER） in metal（Zn, Cr）-catalyzed copolymerization of COS（and CS2） with epoxides. Therefore, it is very promising to learn from HCAⅡ enzyme to develop biomimetic catalyst for highly active CO2/epoxide copolymerization in a well-controlled manner under mild conditions.
基金supported by the National Research Foundation of Korea (NRF)grant funded by the Korean government (MSIP) (2018R1A6A1A03025708)。
文摘Direct growth of redox-active noble metals and rational design of multifunctional electrochemical active materials play crucial roles in developing novel electrode materials for energy storage devices.In this regard,silver(Ag)has attracted great attention in the design of efficient electrodes.Inspired by the house/building process,which means electing the right land,it lays a strong foundation and building essential columns for a complex structure.Herein,we report the construction of multifaceted heterostructure cobalt-iron hydroxide(CFOH)nanowires(NWs)@nickel cobalt manganese hydroxides and/or hydrate(NCMOH)nanosheets(NSs)on the Ag-deposited nickel foam and carbon cloth(i.e.,Ag/NF and Ag/CC)substrates.Moreover,the formation and charge storage mechanism of Ag are described,and these contribute to good conductive and redox chemistry features.The switching architectural integrity of metal and redox materials on metallic frames may significantly boost charge storage and rate performance with noticeable drop in resistance.The as-fabricated Ag@CFOH@NCMOH/NF electrode delivered superior areal capacity value of 2081.9μA h cm^(-2)at 5 mA cm^(-2).Moreover,as-assembled hybrid cell based on NF(HC/NF)device exhibited remarkable areal capacity value of 1.82 mA h cm^(-2)at 5 mA cm^(-2)with excellent rate capability of 74.77%even at 70 mA cm^(-2)Furthermore,HC/NF device achieved maximum energy and power densities of 1.39 mW h cm^(-2)and 42.35 mW cm^(-2),respectively.To verify practical applicability,both devices were also tested to serve as a self-charging station for various portable electronic devices.
