Six hydrothermal sediment samples were collected from the Xunmei and Tongguan hydrothermal fields along the southern Mid-Atlantic Ridge during the China Ocean Cruise DY46 in 2017.Sulfides and oxides in the samples wer...Six hydrothermal sediment samples were collected from the Xunmei and Tongguan hydrothermal fields along the southern Mid-Atlantic Ridge during the China Ocean Cruise DY46 in 2017.Sulfides and oxides in the samples were separated,and Cu and Zn isotope compositions were analyzed.Results show that the ranges ofδ^(65)Cu values of the bulk sediments,sulfides,and oxides were 0.36‰-2.46‰,-0.21‰-1.10‰,and 0.68‰-1.52‰,respectively.Theδ^(65)Cu values of sulfides in four samples(46II-14,46II-30,46III-06,and 46II-09)were relatively low(-0.21‰-0.50‰),corresponding to theδ^(65)Cu values of sulfides from inactive old hydrothermal chimneys in northern Mid-Atlantic Ridge(n MAR),suggesting that the sulfides in the sediments were originated from collapsed dead chimney mainly.While theδ^(65)Cu values of the other two samples(46III-02 and 46III-08)were relatively high(1.10‰-0.96‰),corresponding to theδ^(65)Cu values for active hydrothermal chimneys sulfides in n MAR,which indicated that the sulfides in these two samples might mainly come from sulfide particles settled from active hydrothermal plume.Because of the high density of sulfide particles,they tended to settle near the hydrothermal vents first.Therefore,highδ^(65)Cu values of sulfides in 46III-02 and 46III-08 implied that undiscovered active hydrothermal vents near the sampling positions of 46III-02 in the Xunmei hydrothermal field and 46III-08 in the Tongguan hydrothermal field.Theδ^(66)Zn values of hydrothermal sediments and sulfides ranged 0.11‰-0.43‰and 0.29‰-0.67‰,respectively.In the four samples from the Xunmei hydrothermal field,a positive correlation was found between the distance of the sampling position from sulfide mineralized spot and the Zn isotopic ratio,showing that the greater the distance from the mineralized spot,the heavier the Zn isotope composition as seen in two samples(46II-30 and 46II-14)of the Xunmei-3 spot.This result aligned with the findings of Wilkinson et al.(2005)and Baumgartner et al.(2023),suggesting that the lower the Zn isotope composition,the closer it is to the hydrothermal vent.However,in the Xunmei hydrothermal field,the Zn isotope composition in the other two samples(46III-02and 46III-06)showed the opposite trend.This indicated that there might be an active hydrothermal vent near the sampling location of sample 46III-02.This observation aligned with the Cu isotope analysis results.This study showed that Cu-Zn isotopes are good indicators for understanding the formation mechanisms of hydrothermal sediments and for locating active hydrothermal vents.展开更多
The electrochemical CO_(2)reduction reaction to produce multi-carbon(C_(2+)) hydrocarbons or oxygenate compounds is a promising route to obtain a renewable fuel of high energy density.However,producing C_(2+)at high c...The electrochemical CO_(2)reduction reaction to produce multi-carbon(C_(2+)) hydrocarbons or oxygenate compounds is a promising route to obtain a renewable fuel of high energy density.However,producing C_(2+)at high current densities is still a challenge.Herein,we develop a Cu-Zn alloy/Cu-Zn aluminate oxide composite electrocatalytic system for enhanced conversion of CO_(2)to C_(2+)products.The Cu-Zn-Al-Layered Double Hydroxide(LDH) is used as a precursor to decompose into uniform Cu-Zn oxide/Cu-Zn aluminate pre-catalyst.Under electrochemical reduction,Cu-Zn oxide generates Cu-Zn alloy while Cu-Zn aluminate oxide remains unchanged.The alloy and oxide are closely stacked and arranged alternately,and the aluminate oxide induces the strong electron interaction of Cu,Zn and Al,creating a large number of highly active reaction interfaces composed of 0 to+3 valence metal sites.With the help of the interface effect,the optimized Cu_(9)Zn_(1)/Cu_(0.8)Zn_(0.2)Al_(2)O_(4)catalyst achieves a Faradaic efficiency of 88.5% for C_(2+)products at a current density of 400 mA cm^(-2)at-1.15 V versus reversible hydrogen electrode.The in-situ Raman and attenuate total reflectance-infrared absorption spectroscopy(ATR-IRAS) spectra show that the aluminate oxide at the interface significantly enhances the adsorption and activation of CO_(2)and the dissociation of H2O and strengthens the adsorption of CO intermediates,and the alloy promotes the C-C coupling to produce C_(2+)products.This work provides an efficient strategy to construct highly active reaction interfaces for industrial-scale electrochemical CO_(2)RR.展开更多
The thermal expansion coefficients of Cu-Zn alloy before and after high pressure treatment were measured by thermal expansion instrument in the temperature range of 25？700 ℃,and the microstructure and phase transfor...The thermal expansion coefficients of Cu-Zn alloy before and after high pressure treatment were measured by thermal expansion instrument in the temperature range of 25？700 ℃,and the microstructure and phase transformation of the alloy were examined by optical microscope,X-ray diffractometer（XRD） and differential scanning calorimeter（DSC）.Based on the experimental results,the effects of high pressure treatment on the microstructure and thermal expansion of Cu-Zn alloy were investigated.The results show that the high pressure treatment can refine the grain and increase the thermal expansion coefficient of the Cu-Zn alloy,resulting in that the thermal expansion coefficient exhibits a high peak value on the α-T curve,and the peak value decreases with increasing the pressure.展开更多
基金Supported by the National Natural Science Foundation of China(No.42106080)the Laboratory for Marine Geology+2 种基金China Ocean Mineral Resources R&D Association Project(No.DY135-S2-2-03)the Natural Science Foundation of Shandong Province(No.ZR2020QD074)the Talents Research Start-up Funding Project of Ludong University。
文摘Six hydrothermal sediment samples were collected from the Xunmei and Tongguan hydrothermal fields along the southern Mid-Atlantic Ridge during the China Ocean Cruise DY46 in 2017.Sulfides and oxides in the samples were separated,and Cu and Zn isotope compositions were analyzed.Results show that the ranges ofδ^(65)Cu values of the bulk sediments,sulfides,and oxides were 0.36‰-2.46‰,-0.21‰-1.10‰,and 0.68‰-1.52‰,respectively.Theδ^(65)Cu values of sulfides in four samples(46II-14,46II-30,46III-06,and 46II-09)were relatively low(-0.21‰-0.50‰),corresponding to theδ^(65)Cu values of sulfides from inactive old hydrothermal chimneys in northern Mid-Atlantic Ridge(n MAR),suggesting that the sulfides in the sediments were originated from collapsed dead chimney mainly.While theδ^(65)Cu values of the other two samples(46III-02 and 46III-08)were relatively high(1.10‰-0.96‰),corresponding to theδ^(65)Cu values for active hydrothermal chimneys sulfides in n MAR,which indicated that the sulfides in these two samples might mainly come from sulfide particles settled from active hydrothermal plume.Because of the high density of sulfide particles,they tended to settle near the hydrothermal vents first.Therefore,highδ^(65)Cu values of sulfides in 46III-02 and 46III-08 implied that undiscovered active hydrothermal vents near the sampling positions of 46III-02 in the Xunmei hydrothermal field and 46III-08 in the Tongguan hydrothermal field.Theδ^(66)Zn values of hydrothermal sediments and sulfides ranged 0.11‰-0.43‰and 0.29‰-0.67‰,respectively.In the four samples from the Xunmei hydrothermal field,a positive correlation was found between the distance of the sampling position from sulfide mineralized spot and the Zn isotopic ratio,showing that the greater the distance from the mineralized spot,the heavier the Zn isotope composition as seen in two samples(46II-30 and 46II-14)of the Xunmei-3 spot.This result aligned with the findings of Wilkinson et al.(2005)and Baumgartner et al.(2023),suggesting that the lower the Zn isotope composition,the closer it is to the hydrothermal vent.However,in the Xunmei hydrothermal field,the Zn isotope composition in the other two samples(46III-02and 46III-06)showed the opposite trend.This indicated that there might be an active hydrothermal vent near the sampling location of sample 46III-02.This observation aligned with the Cu isotope analysis results.This study showed that Cu-Zn isotopes are good indicators for understanding the formation mechanisms of hydrothermal sediments and for locating active hydrothermal vents.
基金supported by the National Natural Science Foundation of China (NSFC)(22075201)the National Key Research and Development Program of China (2022YFB4101800)。
文摘The electrochemical CO_(2)reduction reaction to produce multi-carbon(C_(2+)) hydrocarbons or oxygenate compounds is a promising route to obtain a renewable fuel of high energy density.However,producing C_(2+)at high current densities is still a challenge.Herein,we develop a Cu-Zn alloy/Cu-Zn aluminate oxide composite electrocatalytic system for enhanced conversion of CO_(2)to C_(2+)products.The Cu-Zn-Al-Layered Double Hydroxide(LDH) is used as a precursor to decompose into uniform Cu-Zn oxide/Cu-Zn aluminate pre-catalyst.Under electrochemical reduction,Cu-Zn oxide generates Cu-Zn alloy while Cu-Zn aluminate oxide remains unchanged.The alloy and oxide are closely stacked and arranged alternately,and the aluminate oxide induces the strong electron interaction of Cu,Zn and Al,creating a large number of highly active reaction interfaces composed of 0 to+3 valence metal sites.With the help of the interface effect,the optimized Cu_(9)Zn_(1)/Cu_(0.8)Zn_(0.2)Al_(2)O_(4)catalyst achieves a Faradaic efficiency of 88.5% for C_(2+)products at a current density of 400 mA cm^(-2)at-1.15 V versus reversible hydrogen electrode.The in-situ Raman and attenuate total reflectance-infrared absorption spectroscopy(ATR-IRAS) spectra show that the aluminate oxide at the interface significantly enhances the adsorption and activation of CO_(2)and the dissociation of H2O and strengthens the adsorption of CO intermediates,and the alloy promotes the C-C coupling to produce C_(2+)products.This work provides an efficient strategy to construct highly active reaction interfaces for industrial-scale electrochemical CO_(2)RR.
基金Project(11541012) supported by the Scientific Research Foundation of Heilongjiang Provincial Education Department,China
文摘The thermal expansion coefficients of Cu-Zn alloy before and after high pressure treatment were measured by thermal expansion instrument in the temperature range of 25？700 ℃,and the microstructure and phase transformation of the alloy were examined by optical microscope,X-ray diffractometer（XRD） and differential scanning calorimeter（DSC）.Based on the experimental results,the effects of high pressure treatment on the microstructure and thermal expansion of Cu-Zn alloy were investigated.The results show that the high pressure treatment can refine the grain and increase the thermal expansion coefficient of the Cu-Zn alloy,resulting in that the thermal expansion coefficient exhibits a high peak value on the α-T curve,and the peak value decreases with increasing the pressure.
