锂硫电池由于其高理论比容量而备受瞩目,然而其商业化进程仍受到中间产物的穿梭效应、硫的绝缘性和正极体积膨胀等一系列问题的阻碍.为了有效抑制穿梭效应,通过水热法合成了一种以钴和镍为主体的笼状中空双金属硫化物(Ni_(3-x)Co_(x)S_(...锂硫电池由于其高理论比容量而备受瞩目,然而其商业化进程仍受到中间产物的穿梭效应、硫的绝缘性和正极体积膨胀等一系列问题的阻碍.为了有效抑制穿梭效应,通过水热法合成了一种以钴和镍为主体的笼状中空双金属硫化物(Ni_(3-x)Co_(x)S_(4)),并将其作为隔膜部分组装到Li-S电池中.其中空结构的特点为氧化还原反应提供了足够的活性位点,进而可以达到更大的比容量,本工作发现,采用最佳比例(2∶1)的笼状Ni_(3-x)Co_(x)S_(4)材料能够通过物理吸附和化学固定促进多硫化物的转化,有效限制多硫化物的穿梭,提高电导率,并促进锂离子的扩散.实验结果显示,笼状Ni_(3-x)Co_(x)S_(4)材料表现出优异的性能,包括在0.1 C下达到1184.3 mAh g^(-1)的初始容量以及在0.2 C循环200圈后仍保持564.4 mAh g^(-1)的比容量.展开更多
Preparation of highly active hydrodesulfurization catalysts is extremely meaningful for the sulfur removal from thiophene substances.In this work,commercial nano-Al_(2)O_(3)with mesoporous structure supported monometa...Preparation of highly active hydrodesulfurization catalysts is extremely meaningful for the sulfur removal from thiophene substances.In this work,commercial nano-Al_(2)O_(3)with mesoporous structure supported monometallic phosphide(NiP/Al_(2)O_(3)and MoP/Al_(2)O_(3))and bimetallic phosphide(NiMoP/Al_(2)O_(3)with various Ni/Mo molar ratio)catalysts are successfully prepared by temperature-programmed reduction.X-ray diffraction(XRD)result shows the Ni/Mo molar ratio affect the crystal phase in catalysts.Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)characterizations co-confirm the interact between Ni and Mo elements in bimetallic phosphide.Catalyst evaluation in hydrodesulfurization of dibenzothiophene shows that bimetallic phosphide samples exhibit better catalytic performance than monometallic phosphide.62.1%conversion and 86.3%biphenyl selectivity with 30 h stability are achieved over NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst at 400℃under 3 MPa H_(2).All characterization results demonstrate that the improved activity of bimetallic phosphide owes to the Ni-Mo synergistic effect in NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst.This finding provides a guide to the design of bimetallic catalyst with synergistic effect.展开更多
文摘锂硫电池由于其高理论比容量而备受瞩目,然而其商业化进程仍受到中间产物的穿梭效应、硫的绝缘性和正极体积膨胀等一系列问题的阻碍.为了有效抑制穿梭效应,通过水热法合成了一种以钴和镍为主体的笼状中空双金属硫化物(Ni_(3-x)Co_(x)S_(4)),并将其作为隔膜部分组装到Li-S电池中.其中空结构的特点为氧化还原反应提供了足够的活性位点,进而可以达到更大的比容量,本工作发现,采用最佳比例(2∶1)的笼状Ni_(3-x)Co_(x)S_(4)材料能够通过物理吸附和化学固定促进多硫化物的转化,有效限制多硫化物的穿梭,提高电导率,并促进锂离子的扩散.实验结果显示,笼状Ni_(3-x)Co_(x)S_(4)材料表现出优异的性能,包括在0.1 C下达到1184.3 mAh g^(-1)的初始容量以及在0.2 C循环200圈后仍保持564.4 mAh g^(-1)的比容量.
基金supported by the National Key R&D Program of China(No.2021YFF0500600)National Natural Science Foundation of China(Nos.51932005 and 52022041)+1 种基金All-Solid-State Lithium Battery Electrolyte Engineering Research Centre(XMHT20200203006)the China Postdoctoral Science Foundation(2022M710041).
基金supported by National Natural Science Foundation of China(22202093)the Scientific and Technological Innovation Youth Talent Team of Shanxi Province(202204051001005)。
文摘Preparation of highly active hydrodesulfurization catalysts is extremely meaningful for the sulfur removal from thiophene substances.In this work,commercial nano-Al_(2)O_(3)with mesoporous structure supported monometallic phosphide(NiP/Al_(2)O_(3)and MoP/Al_(2)O_(3))and bimetallic phosphide(NiMoP/Al_(2)O_(3)with various Ni/Mo molar ratio)catalysts are successfully prepared by temperature-programmed reduction.X-ray diffraction(XRD)result shows the Ni/Mo molar ratio affect the crystal phase in catalysts.Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)characterizations co-confirm the interact between Ni and Mo elements in bimetallic phosphide.Catalyst evaluation in hydrodesulfurization of dibenzothiophene shows that bimetallic phosphide samples exhibit better catalytic performance than monometallic phosphide.62.1%conversion and 86.3%biphenyl selectivity with 30 h stability are achieved over NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst at 400℃under 3 MPa H_(2).All characterization results demonstrate that the improved activity of bimetallic phosphide owes to the Ni-Mo synergistic effect in NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst.This finding provides a guide to the design of bimetallic catalyst with synergistic effect.
