Dry reforming of methane(DRM)converts CH4 and CO_(2) to syngas.Photothermal DRM,which integrates temperature and light,is a sustainable method for storing solar energy in molecules.However,challenges such as limited l...Dry reforming of methane(DRM)converts CH4 and CO_(2) to syngas.Photothermal DRM,which integrates temperature and light,is a sustainable method for storing solar energy in molecules.However,challenges such as limited light absorption,low photocarrier separation efficiency,Ni sintering,and carbon deposition hinder DRM stability.Herein,we regulated Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance the optical characteristics while addressing Ni sintering and carbon deposition issues.The(3Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst had insufficient Ni content,while the(9Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst showed excessive carbon deposition,leading to lower stability compared to the(6Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst,which achieved CH4 and CO_(2) rates to 231.0 μmol gcat^(-1)s^(-1) and 294.3 μmol gcat^(-1)s^(-1) ,respectively,at 973 K,with only 0.2 wt.%carbon deposition and no Ni sintering.This work adjusted Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance DRM performance,which has implications for improving other reactions.展开更多
Carbon nanotubes (CNTs) were prepared by decomposition of C2H2 over newly developed LaCu0.2Ni0.8Ox in the temperature range from 600 to 850℃. The effect of the reaction temperature on the yield of CNTs was investiga...Carbon nanotubes (CNTs) were prepared by decomposition of C2H2 over newly developed LaCu0.2Ni0.8Ox in the temperature range from 600 to 850℃. The effect of the reaction temperature on the yield of CNTs was investigated in detail. At 680℃,the yield of CNTs reaches 17 g/g.catal. or so. The morphology of CNTs was examined by TEM. The diameter of CNTs rangs from 9 nm to 14 nm.展开更多
Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increa...Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increasing the lithium content. SEM revealed that the morphology of particles changed from rounded polyhedral-like crystallites to sharp-edged polyhedral crystals with more doped lithium. EDX showed that the stoichiometries of Ni and Co agrees with calculated synthesized values. Electrochemical studies revealed the overlithiated samples have improved capacities as well as cycling behavior. The sample with x = 0.05 shows the best performance with a specific capacity of 113.29 mA.h.g-1 and the best capacity retention of 92.2% over 10 cycles. XPS results showed that the binding energy of Li ls is decreased for the Li doped samples with the smallest value for the x = 0.05 sample, implying that Li＋ ions can be extracted more easily from Li1.05Ni0.8Co0.2O2 than the other stoichiometries accounting for the improved performance of the material. Considerations of core level XPS peaks for transition metals reveal the existence in several oxidation states. However, the percentage of the＋3 oxidation state of transition metals for the when x = 0.1 is the highest and the availability for charge transition from the ＋3 to＋4 state of the transition metal during deintercalation is more readily available.展开更多
基金support from the National Natural Science Foundation of China(22078134)State Key Laboratory of Clean and Efficient Coal Utilization of Taiyuan University of Technology(SKL2022006)Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0162)are greatly appreciated for the work.
文摘Dry reforming of methane(DRM)converts CH4 and CO_(2) to syngas.Photothermal DRM,which integrates temperature and light,is a sustainable method for storing solar energy in molecules.However,challenges such as limited light absorption,low photocarrier separation efficiency,Ni sintering,and carbon deposition hinder DRM stability.Herein,we regulated Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance the optical characteristics while addressing Ni sintering and carbon deposition issues.The(3Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst had insufficient Ni content,while the(9Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst showed excessive carbon deposition,leading to lower stability compared to the(6Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst,which achieved CH4 and CO_(2) rates to 231.0 μmol gcat^(-1)s^(-1) and 294.3 μmol gcat^(-1)s^(-1) ,respectively,at 973 K,with only 0.2 wt.%carbon deposition and no Ni sintering.This work adjusted Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance DRM performance,which has implications for improving other reactions.
文摘Carbon nanotubes (CNTs) were prepared by decomposition of C2H2 over newly developed LaCu0.2Ni0.8Ox in the temperature range from 600 to 850℃. The effect of the reaction temperature on the yield of CNTs was investigated in detail. At 680℃,the yield of CNTs reaches 17 g/g.catal. or so. The morphology of CNTs was examined by TEM. The diameter of CNTs rangs from 9 nm to 14 nm.
文摘Pure, layered compounds of overlithiated Li1＋xNi0.8Co0.2O2（x = 0.05 and 0.1） were successfully prepared by a modified combustion method. XRD studies showed that cell parameters of the material decreased with increasing the lithium content. SEM revealed that the morphology of particles changed from rounded polyhedral-like crystallites to sharp-edged polyhedral crystals with more doped lithium. EDX showed that the stoichiometries of Ni and Co agrees with calculated synthesized values. Electrochemical studies revealed the overlithiated samples have improved capacities as well as cycling behavior. The sample with x = 0.05 shows the best performance with a specific capacity of 113.29 mA.h.g-1 and the best capacity retention of 92.2% over 10 cycles. XPS results showed that the binding energy of Li ls is decreased for the Li doped samples with the smallest value for the x = 0.05 sample, implying that Li＋ ions can be extracted more easily from Li1.05Ni0.8Co0.2O2 than the other stoichiometries accounting for the improved performance of the material. Considerations of core level XPS peaks for transition metals reveal the existence in several oxidation states. However, the percentage of the＋3 oxidation state of transition metals for the when x = 0.1 is the highest and the availability for charge transition from the ＋3 to＋4 state of the transition metal during deintercalation is more readily available.
