Adsorption by solid amine adsorbent is a promising technology for decarbonization of flue gas.However,adsorption properties of many solid amine adsorbents need to be enhanced,and it is necessary to further study the C...Adsorption by solid amine adsorbent is a promising technology for decarbonization of flue gas.However,adsorption properties of many solid amine adsorbents need to be enhanced,and it is necessary to further study the CO_(2)adsorption mechanism.A novel CO_(2)adsorbent with high capacity was obtained by grafting 3-aminopropyltriethoxysilane(APTES)on a micro-mesoporous composite molecular sieve ZSM-5/MCM-48 as the support,and then impregnated with tetraethylenepentamine(TEPA)or polyethyleneimine(PEI).The maximum adsorption capacity of APTES-ZSM-5/MCM-48-TEPA-60(A-ZM-T60),loaded with 60%(in mass)TEPA,for CO_(2)reaches 5.82 mmol·g^(-1) at 60℃in 15%(in volume)CO_(2).Carbamate,alkyl ammonium carbamate and carbonate are generated during the chemical adsorption,which is dominant for CO_(2)adsorption because of the reaction between CO_(2)and amino groups on the adsorbent,simultaneously accompanied by weak physical adsorption.All above data confirm that these composites display an outstanding adsorption performance with a bright future for CO_(2)capture from flue gas after desulfurization.展开更多
The sluggish kinetics of the sulfur redox reaction(SRR)and the shuttling effect of lithium polysulfides(LiPSs)both restrict the practical application of lithium-sulfur(Li-S)batteries.Heterostructures,with their pronou...The sluggish kinetics of the sulfur redox reaction(SRR)and the shuttling effect of lithium polysulfides(LiPSs)both restrict the practical application of lithium-sulfur(Li-S)batteries.Heterostructures,with their pronounced electroactivity and structural stability,showcase their potential as electrodes/functional separators for lithium-sulfur batteries.Herein,we proposed a bifunctional catalyst exhibiting strong adsorption and rapid catalytic conversion of LiPSs through in situ UV photocatalytic synthesis of Ti_(3)C_(2)@TiO_(2)heterostructure.The TiO_(2)nanoparticles act as the anchoring center for LiPSs,while the electrically conductive Ti_(3)C_(2)ensures the rapid diffusion of these LiPSs from TiO_(2)to the catalytically active Ti_(3)C_(2)layer across heterogeneous interfaces.The Li-S batteries with Ti_(3)C_(2)@TiO_(2)-40 min-PP separator delivered a high initial capacity of 1283 mA∙h/g,which decreased slightly to 691 mA∙h/g after 200 cycles at 1C.This work advances the understanding of the synergistic effect of polysulfide adsorbents and conductive agents in inhibiting shuttle effects,and offers a method for designing polysulfide barriers in lithium-sulfur batteries.展开更多
The phase composition, phase transition and phase structure transformation of the wire-cut section of functionally graded WC-Co cemented carbide with dual phase structure were investigated by XRD phase analysis. It is...The phase composition, phase transition and phase structure transformation of the wire-cut section of functionally graded WC-Co cemented carbide with dual phase structure were investigated by XRD phase analysis. It is shown that the composition of η phase in the core zone is Co_3W_3C (M_6 C type). The structure of cobalt based solid solution binder phase is fcc type. At the cooling stage of the sintering process, the phase transition of η phase, i.e. M_6C→M_12C and the martensitic phase transition of the cobalt based solid solution binder phase, i.e. fcc→hcp are suppressed, which facilitates the strengthening of the alloy. Because the instantaneous temperature of the discharge channel is as high as 10 000 ℃ during the wire cutting process, the processed surface is oxidized. Nevertheless, the oxide layer thickness is in micro grade. In the oxide film, η phase is decomposed into W_2C and CoO, and cobalt based solid solution binder is selectively oxidized, while WC remains stable due to the existence of carbon containing liquid organic cutting medium.展开更多
基金National Natural Science Foundation of China(51966002)Natural Science Foundation of Guangxi Province(2020GXNSFAA159144)。
文摘Adsorption by solid amine adsorbent is a promising technology for decarbonization of flue gas.However,adsorption properties of many solid amine adsorbents need to be enhanced,and it is necessary to further study the CO_(2)adsorption mechanism.A novel CO_(2)adsorbent with high capacity was obtained by grafting 3-aminopropyltriethoxysilane(APTES)on a micro-mesoporous composite molecular sieve ZSM-5/MCM-48 as the support,and then impregnated with tetraethylenepentamine(TEPA)or polyethyleneimine(PEI).The maximum adsorption capacity of APTES-ZSM-5/MCM-48-TEPA-60(A-ZM-T60),loaded with 60%(in mass)TEPA,for CO_(2)reaches 5.82 mmol·g^(-1) at 60℃in 15%(in volume)CO_(2).Carbamate,alkyl ammonium carbamate and carbonate are generated during the chemical adsorption,which is dominant for CO_(2)adsorption because of the reaction between CO_(2)and amino groups on the adsorbent,simultaneously accompanied by weak physical adsorption.All above data confirm that these composites display an outstanding adsorption performance with a bright future for CO_(2)capture from flue gas after desulfurization.
基金Project(2023JJ10062)supported by the Hunan Province Funds for Distinguished Young Scientists,ChinaProject(2023RC3051)supported by the Science and Technology Innovation Program of Hunan Province of ChinaProject(kh2401026)supported by the Science and Technology Program of Changsha of China。
文摘The sluggish kinetics of the sulfur redox reaction(SRR)and the shuttling effect of lithium polysulfides(LiPSs)both restrict the practical application of lithium-sulfur(Li-S)batteries.Heterostructures,with their pronounced electroactivity and structural stability,showcase their potential as electrodes/functional separators for lithium-sulfur batteries.Herein,we proposed a bifunctional catalyst exhibiting strong adsorption and rapid catalytic conversion of LiPSs through in situ UV photocatalytic synthesis of Ti_(3)C_(2)@TiO_(2)heterostructure.The TiO_(2)nanoparticles act as the anchoring center for LiPSs,while the electrically conductive Ti_(3)C_(2)ensures the rapid diffusion of these LiPSs from TiO_(2)to the catalytically active Ti_(3)C_(2)layer across heterogeneous interfaces.The Li-S batteries with Ti_(3)C_(2)@TiO_(2)-40 min-PP separator delivered a high initial capacity of 1283 mA∙h/g,which decreased slightly to 691 mA∙h/g after 200 cycles at 1C.This work advances the understanding of the synergistic effect of polysulfide adsorbents and conductive agents in inhibiting shuttle effects,and offers a method for designing polysulfide barriers in lithium-sulfur batteries.
基金Projects(50323008, 50574104) supported by the National Natural Science Foundation of ChinaProject (04JJ3084) supported by the Natural Science Foundation of Hunan Province, China
文摘The phase composition, phase transition and phase structure transformation of the wire-cut section of functionally graded WC-Co cemented carbide with dual phase structure were investigated by XRD phase analysis. It is shown that the composition of η phase in the core zone is Co_3W_3C (M_6 C type). The structure of cobalt based solid solution binder phase is fcc type. At the cooling stage of the sintering process, the phase transition of η phase, i.e. M_6C→M_12C and the martensitic phase transition of the cobalt based solid solution binder phase, i.e. fcc→hcp are suppressed, which facilitates the strengthening of the alloy. Because the instantaneous temperature of the discharge channel is as high as 10 000 ℃ during the wire cutting process, the processed surface is oxidized. Nevertheless, the oxide layer thickness is in micro grade. In the oxide film, η phase is decomposed into W_2C and CoO, and cobalt based solid solution binder is selectively oxidized, while WC remains stable due to the existence of carbon containing liquid organic cutting medium.
