Removal of Co(Ⅱ) from aqueous solutions by complexation-ultrafiltration was investigated using polyacrylic acid sodium(PAAS) as complexing agent with the help of rotating disk membrane,and the shear ability of PAA-Co...Removal of Co(Ⅱ) from aqueous solutions by complexation-ultrafiltration was investigated using polyacrylic acid sodium(PAAS) as complexing agent with the help of rotating disk membrane,and the shear ability of PAA-Co complex was studied. The effects of the mass ratio of PAAS to Co(Ⅱ)(P/M) and pH on the rejection of Co(Ⅱ) were studied,and the optimum conditions were P/M=8 and pH=7. The rejection of Co(Ⅱ) was over 97% when the rotating speed of the disk(n)was less than 710 r/min at the optimum P/M and pH. The distribution of the forms of cobalt on the membrane surface was established by the membrane partition model, and the critical shear rate,the smallest shear rate at which the PAA-Co complex begins to dissociate,was calculated to be1.4×10^4 s^-1,and the corresponding rotating speed was 710 r/min.The PAA-Co complex dissociated when the shear rate was greater than the critical one. The regeneration of PAAS and recovery of Co(Ⅱ) were achieved by shear-induced dissociation and ultrafiltration.展开更多
Electrochemical reduction reactions,including the oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),carbon dioxide reduction reaction(CRR),and nitrate reduction reaction(NRR),hold promise for energy conv...Electrochemical reduction reactions,including the oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),carbon dioxide reduction reaction(CRR),and nitrate reduction reaction(NRR),hold promise for energy conversion and storage.However,electrocatalysts exhibit slow kinetics and inactivation effects,resulting in inadequate energy efficiency and poor stability.To address these challenges,the groupⅧelement-based single-atom electrocatalysts(GVSAEs)were endowed with tunable electronic structures and porous carbon substrates to reduce intermediate adsorption and desorption energy barriers,which can accelerate electrochemical kinetics.This mini review summarises the recent achievements in GVSAEs with electronic structure and porous substrate engineering discussions.Furthermore,these GVSAEs are divided into non-noble iron series element(Fe,Co,and Ni)single-atom electrocatalysts and noble platinum series elements(Ru,Rh,Pd,Os,Ir,and Pt)based single-atom electrocatalysts for the ORR,HER,CRR,and NRR,where the porous substrate structure,electronic structure,and catalytic activity are discussed.Finally,conclusions and perspectives relating to future challenges and potential opportunities are provided for electrocatalysis with better performance.展开更多
In this paper, we conduct research on the development trend of Zinc leaching residue and the construction of environment friendly system. To further strengthen concentration degree of the chemical industry, improve th...In this paper, we conduct research on the development trend of Zinc leaching residue and the construction of environment friendly system. To further strengthen concentration degree of the chemical industry, improve the production efficiency and utilization rate of emissions, realize the comprehensive utilization of energy development and the green development. In China＇ s zinc smelting industry, the use of most of the zinc smelting raw materials contain a small amount of the cobalt, zinc in the process of leaching into the zinc sulfate solution, as a harmful effect of the zinc impurities. For zinc sulfate leaching solution cobalt purification, most of the factories are using zinc powder replacement purification method, the output of the purification of zinc slag in the vast majority of zinc with small part of cadmium and a small amount of nickel, cobalt, copper, manganese and so on. This paper proposes the novel systematic method of the Zinc leaching residue re-use that will promote the further development of the green industry.展开更多
The regio-and enantioselective functionalization of 1,3-dienes has become a powerful tool for the synthesis of allylic compounds,yet it remains a challenge for aliphatic dienes.Herein,we report a nickel-catalyzed asym...The regio-and enantioselective functionalization of 1,3-dienes has become a powerful tool for the synthesis of allylic compounds,yet it remains a challenge for aliphatic dienes.Herein,we report a nickel-catalyzed asymmetric hydroarylation reaction of aliphatic and aromatic dienes with indoles to afford chiral indole derivatives.展开更多
基金Project(24176265)supported by the National Natural Science Foundation of China
文摘Removal of Co(Ⅱ) from aqueous solutions by complexation-ultrafiltration was investigated using polyacrylic acid sodium(PAAS) as complexing agent with the help of rotating disk membrane,and the shear ability of PAA-Co complex was studied. The effects of the mass ratio of PAAS to Co(Ⅱ)(P/M) and pH on the rejection of Co(Ⅱ) were studied,and the optimum conditions were P/M=8 and pH=7. The rejection of Co(Ⅱ) was over 97% when the rotating speed of the disk(n)was less than 710 r/min at the optimum P/M and pH. The distribution of the forms of cobalt on the membrane surface was established by the membrane partition model, and the critical shear rate,the smallest shear rate at which the PAA-Co complex begins to dissociate,was calculated to be1.4×10^4 s^-1,and the corresponding rotating speed was 710 r/min.The PAA-Co complex dissociated when the shear rate was greater than the critical one. The regeneration of PAAS and recovery of Co(Ⅱ) were achieved by shear-induced dissociation and ultrafiltration.
基金supported by the National Natural Science Foundation of China-Yunnan Joint Fund(No.U2002213)the Science and Technology Talent and Platform Program of Yunnan Provincial Science and Technology Department(No.202305AM070001)+1 种基金Open Foundation of Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials(No.2022GXYSOF10)Double First University Plan(No.C176220100042)
文摘Electrochemical reduction reactions,including the oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),carbon dioxide reduction reaction(CRR),and nitrate reduction reaction(NRR),hold promise for energy conversion and storage.However,electrocatalysts exhibit slow kinetics and inactivation effects,resulting in inadequate energy efficiency and poor stability.To address these challenges,the groupⅧelement-based single-atom electrocatalysts(GVSAEs)were endowed with tunable electronic structures and porous carbon substrates to reduce intermediate adsorption and desorption energy barriers,which can accelerate electrochemical kinetics.This mini review summarises the recent achievements in GVSAEs with electronic structure and porous substrate engineering discussions.Furthermore,these GVSAEs are divided into non-noble iron series element(Fe,Co,and Ni)single-atom electrocatalysts and noble platinum series elements(Ru,Rh,Pd,Os,Ir,and Pt)based single-atom electrocatalysts for the ORR,HER,CRR,and NRR,where the porous substrate structure,electronic structure,and catalytic activity are discussed.Finally,conclusions and perspectives relating to future challenges and potential opportunities are provided for electrocatalysis with better performance.
文摘In this paper, we conduct research on the development trend of Zinc leaching residue and the construction of environment friendly system. To further strengthen concentration degree of the chemical industry, improve the production efficiency and utilization rate of emissions, realize the comprehensive utilization of energy development and the green development. In China＇ s zinc smelting industry, the use of most of the zinc smelting raw materials contain a small amount of the cobalt, zinc in the process of leaching into the zinc sulfate solution, as a harmful effect of the zinc impurities. For zinc sulfate leaching solution cobalt purification, most of the factories are using zinc powder replacement purification method, the output of the purification of zinc slag in the vast majority of zinc with small part of cadmium and a small amount of nickel, cobalt, copper, manganese and so on. This paper proposes the novel systematic method of the Zinc leaching residue re-use that will promote the further development of the green industry.
基金the National Natural Science Foundation of China(nos.21790330 and 91956000)and the“111”Project(no.B06005)of the Ministry of Education of China for financial support.
文摘The regio-and enantioselective functionalization of 1,3-dienes has become a powerful tool for the synthesis of allylic compounds,yet it remains a challenge for aliphatic dienes.Herein,we report a nickel-catalyzed asymmetric hydroarylation reaction of aliphatic and aromatic dienes with indoles to afford chiral indole derivatives.
