The oxidation induration and reduction swelling behavior of chromium-bearing vanadium titanomagnetite pellets(CVTP)with Cr2O3 addition were studied,and the reduction swelling index(RSI)and compressive strength(CS)of t...The oxidation induration and reduction swelling behavior of chromium-bearing vanadium titanomagnetite pellets(CVTP)with Cr2O3 addition were studied,and the reduction swelling index(RSI)and compressive strength(CS)of the reduced CVTP with simulated coke oven gas(COG)injection were investigated.The results showed that the CS of the CVTP decreases and the porosity of the CVTP increases with increasing amount of Cr2O3 added.The Cr2O3 mainly exists in the form of(Cr,Fe)2O3 solid solution in the CVTP and as Fe-Cr in the reduced CVTP.The CS of the reduced CVTP increases and the RSI of the reduced CVTP decreases with increasing amount of Cr2O3 added.The limited aggregation and diffusion of metallic iron contribute to the formation of dense lamellar crystals,which leads to the slight decrease for reduction swelling behavior of reduced CVTP.This work provides a theoretical and technical basis for the utilization of CVTP and other Cr-bearing ores such as chromite with COG recycling technology.展开更多
This study introduced TiO2-pillared clays （TiO2-PILC） as a support for the catalytic oxidation of NO and analyzed the performance of chromium oxides as the active site of the oxidation process. Cr-based catalysts we...This study introduced TiO2-pillared clays （TiO2-PILC） as a support for the catalytic oxidation of NO and analyzed the performance of chromium oxides as the active site of the oxidation process. Cr-based catalysts were prepared by a wet impregnation method. It was found that the 10 wt.% chromium doping on the support achieved the best catalytic activity. At 350℃, the NO conversion was 61% under conditions of GHSV = 23600 hr^-l. The BET data showed that the support particles had a mesoporous structure. Hz-TPR showed that Cr（10）TiP （10 wt.% Cr doping on TiO2-PILC） clearly exhibited a smooth single peak. EPR and XPS were used to elucidate the oxidation process. During the NO ＋ O2 adsorption, the intensity of evolution of superoxide ions （O2^-） increased. The content of Cr^3＋ on the surface of the used catalyst was 40.37%, but when the used catalyst continued adsorbing NO, the Cr^3＋ increased to 50.28%. Additionally, Oα/Oβ increased markedly through the oxidation process. The NO conversion decreased when SO2 was added into the system, but when the SO2 was removed, the catalytic activity recovered almost up to the initial level. FT-IR spectra did not show a distinct characteristic peak of SO4^2-.展开更多
单质硅是一种有潜力的高容量锂离子电池负极材料.然而,受限于充放电过程中巨大的体积膨胀,其循环性能并不理想.在这个工作中,我们设计了一种独特的三组分复合负极材料(Si/Cr_(2)O_(3)/C),其中Si纳米颗粒被限域在碳包覆的氧化铬多层空心...单质硅是一种有潜力的高容量锂离子电池负极材料.然而,受限于充放电过程中巨大的体积膨胀,其循环性能并不理想.在这个工作中,我们设计了一种独特的三组分复合负极材料(Si/Cr_(2)O_(3)/C),其中Si纳米颗粒被限域在碳包覆的氧化铬多层空心球(MSHSs)中.得益于Cr_(2)O_(3)/C基体的体积变化缓冲能力与优异的结构稳定性,将Si纳米颗粒封装在MSHSs中可以有效地提高其电化学性能.合理的结构设计赋予了Si/Cr_(2)O_(3)/C三组分复合材料高的可逆容量(在100 mA g^(-1)的电流密度下,比容量为1351 mA h g^(-1))和稳定的循环性能(在500 mA g^(-1)的电流密度下,循环300次后比容量保持在716 mA h g^(-1)).这一工作提出了一种多壳层空心结构设计的新思路,以解决硅基负极材料循环性差的瓶颈.展开更多
A microreactor system was used to study the catalytic reaction of NO+CO→1/2 N_2+CO_2 over Cu,Fe, Mn,Cr,and Ce oxides supported on alumina,and the effect of adding Ce in supported Cu-M-O(M=Mn,Fe and Cr) catalysts on t...A microreactor system was used to study the catalytic reaction of NO+CO→1/2 N_2+CO_2 over Cu,Fe, Mn,Cr,and Ce oxides supported on alumina,and the effect of adding Ce in supported Cu-M-O(M=Mn,Fe and Cr) catalysts on their catalytic activities for the topic reaction and the concentration of N_2O produced.It was found that the catalytic activity order of the single-element oxide is:CuO>Fe_2O_3≈Cr_2O_3> MnO_2>CeO_2>NiO.Cu-Mn-O is more active than CuO,and Cu-Fe-O is more active than Cu-Mn-O and Cu-Cr-O for NO+CO reaction.This study shows that the addition of Ce in supported Cu-M-O can promote their catalytic activities Jot the topic reaction,which makes the reaction of 2NO+CO→N_2O+CO_2 fast,and N_2O is an intermediate compound produced during NO+CO reaction.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.51674084, 51174051, and 51574082)
文摘The oxidation induration and reduction swelling behavior of chromium-bearing vanadium titanomagnetite pellets(CVTP)with Cr2O3 addition were studied,and the reduction swelling index(RSI)and compressive strength(CS)of the reduced CVTP with simulated coke oven gas(COG)injection were investigated.The results showed that the CS of the CVTP decreases and the porosity of the CVTP increases with increasing amount of Cr2O3 added.The Cr2O3 mainly exists in the form of(Cr,Fe)2O3 solid solution in the CVTP and as Fe-Cr in the reduced CVTP.The CS of the reduced CVTP increases and the RSI of the reduced CVTP decreases with increasing amount of Cr2O3 added.The limited aggregation and diffusion of metallic iron contribute to the formation of dense lamellar crystals,which leads to the slight decrease for reduction swelling behavior of reduced CVTP.This work provides a theoretical and technical basis for the utilization of CVTP and other Cr-bearing ores such as chromite with COG recycling technology.
基金supported by the Assembly Foundation of the Industry and Information Ministry of China 2012(543)the National Natural Science Foundation of China(No.U1162119+5 种基金51078185)the Scientific Research Project of Environmental Protection Department of Jiangsu Province(No.2013003201112)the Research Fund for the Doctoral Program of Higher Education of China(No.20113219110009)the Industry-Academia Cooperation Innovation Fund Projects of Jiangsu Province(No.BY2012025)the research fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.AE201001)
文摘This study introduced TiO2-pillared clays （TiO2-PILC） as a support for the catalytic oxidation of NO and analyzed the performance of chromium oxides as the active site of the oxidation process. Cr-based catalysts were prepared by a wet impregnation method. It was found that the 10 wt.% chromium doping on the support achieved the best catalytic activity. At 350℃, the NO conversion was 61% under conditions of GHSV = 23600 hr^-l. The BET data showed that the support particles had a mesoporous structure. Hz-TPR showed that Cr（10）TiP （10 wt.% Cr doping on TiO2-PILC） clearly exhibited a smooth single peak. EPR and XPS were used to elucidate the oxidation process. During the NO ＋ O2 adsorption, the intensity of evolution of superoxide ions （O2^-） increased. The content of Cr^3＋ on the surface of the used catalyst was 40.37%, but when the used catalyst continued adsorbing NO, the Cr^3＋ increased to 50.28%. Additionally, Oα/Oβ increased markedly through the oxidation process. The NO conversion decreased when SO2 was added into the system, but when the SO2 was removed, the catalytic activity recovered almost up to the initial level. FT-IR spectra did not show a distinct characteristic peak of SO4^2-.
基金supported by the Key Research and Development Program of Hubei Province(2021BAA176)Hainan Provincial Natural Science Foundation of China(522CXTD516)。
文摘单质硅是一种有潜力的高容量锂离子电池负极材料.然而,受限于充放电过程中巨大的体积膨胀,其循环性能并不理想.在这个工作中,我们设计了一种独特的三组分复合负极材料(Si/Cr_(2)O_(3)/C),其中Si纳米颗粒被限域在碳包覆的氧化铬多层空心球(MSHSs)中.得益于Cr_(2)O_(3)/C基体的体积变化缓冲能力与优异的结构稳定性,将Si纳米颗粒封装在MSHSs中可以有效地提高其电化学性能.合理的结构设计赋予了Si/Cr_(2)O_(3)/C三组分复合材料高的可逆容量(在100 mA g^(-1)的电流密度下,比容量为1351 mA h g^(-1))和稳定的循环性能(在500 mA g^(-1)的电流密度下,循环300次后比容量保持在716 mA h g^(-1)).这一工作提出了一种多壳层空心结构设计的新思路,以解决硅基负极材料循环性差的瓶颈.
文摘A microreactor system was used to study the catalytic reaction of NO+CO→1/2 N_2+CO_2 over Cu,Fe, Mn,Cr,and Ce oxides supported on alumina,and the effect of adding Ce in supported Cu-M-O(M=Mn,Fe and Cr) catalysts on their catalytic activities for the topic reaction and the concentration of N_2O produced.It was found that the catalytic activity order of the single-element oxide is:CuO>Fe_2O_3≈Cr_2O_3> MnO_2>CeO_2>NiO.Cu-Mn-O is more active than CuO,and Cu-Fe-O is more active than Cu-Mn-O and Cu-Cr-O for NO+CO reaction.This study shows that the addition of Ce in supported Cu-M-O can promote their catalytic activities Jot the topic reaction,which makes the reaction of 2NO+CO→N_2O+CO_2 fast,and N_2O is an intermediate compound produced during NO+CO reaction.
