Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its goo...Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.展开更多
Bone is a hierarchical architecture that consists of both inorganic and organic components.The organic components,including collagen and numerous non-collagenous biomolecules,are crucial for maintaining the mechanical...Bone is a hierarchical architecture that consists of both inorganic and organic components.The organic components,including collagen and numerous non-collagenous biomolecules,are crucial for maintaining the mechanical strength and physiological functions of bone.The native structures of organic components and especially the mutual interactions between different components are important questions to be addressed.Among different analytical techniques,solid-state nuclear magnetic resonance(SSNMR)spectroscopy is a powerful tool to reveal the chemical and interactional information at an atomic level.Recent advancements of SSNMR technology and experimental protocols have brought great advances in understanding the molecular details in native bones.In this review,we summarize the progresses on the SSNMR studies of various organic components in the bone matrix.In the first part,we review the studies on collagen from four different aspects:(1)waterassociated molecular dynamics;(2)the intrahelical/interhelical interactions in collagen residues;(3)the interactions between collagen and citrate;and(4)the cross-linking between collagen and inorganic surface.In the second part,we review the studies on the non-protein biomolecules including sugar species,citrate,lipids,and nucleic acids.In the end,we propose an outlook of future directions for SSNMR investigations on bones.展开更多
H 3PW 12O 40/SiO 2(PW/SiO 2) was prepar ed by the sol-gel method and trimethylolpropane tri-heptanoate(TMH ) was synthes ized by trimethylolpropane(TMP) and heptylic acid(HA) in the presence of H 3PW 12O 40/SiO 2.The ...H 3PW 12O 40/SiO 2(PW/SiO 2) was prepar ed by the sol-gel method and trimethylolpropane tri-heptanoate(TMH ) was synthes ized by trimethylolpropane(TMP) and heptylic acid(HA) in the presence of H 3PW 12O 40/SiO 2.The results showed that the catalyst with 50%(mass)PW had good activity and stability.The optimal esterification conditions were as f ollows:n TMP∶n HA=1∶4,2%(mass)PW/SiO 2,reaction temperature 120—200 ℃ and 3 h.The structure of TMH was characterized by GC,IR, 1HNMR spectra and the rate of esterification was up to 95%.展开更多
为了详尽定性和定量分析ZSM-35分子筛孔道内部和外部的酸中心,对在不同焙烧晶化条件下制备的3种ZSM-35分子筛样品(编号分别为GNJ,GNX,GW)采用NH3-TPD和吸附不同探针分子的31P MAS NMR谱进行表征,并在微反装置上对3种样品进行催化正丁烯...为了详尽定性和定量分析ZSM-35分子筛孔道内部和外部的酸中心,对在不同焙烧晶化条件下制备的3种ZSM-35分子筛样品(编号分别为GNJ,GNX,GW)采用NH3-TPD和吸附不同探针分子的31P MAS NMR谱进行表征,并在微反装置上对3种样品进行催化正丁烯异构化反应性能评价。结果表明:ZSM-35分子筛中Brnsted酸酸量远多于Lewis酸酸量,且不同制备方法得到的ZSM-35分子筛Brnsted酸强度与酸量不同;GNJ主要有1种弱Brnsted酸中心,GW有3种不同强度的Brnsted酸中心,较弱的Brnsted酸中心在孔道内部和外部均有分布,较强的两种Brnsted酸中心主要分布在孔道内部;GNX有两种不同强度的Brnsted酸中心,在孔道内部和外部均有分布,且GNX的Brnsted酸酸量高于GNJ和GW;催化正丁烯异构化反应时,ZSM-35分子筛的中强Brnsted酸中心是异丁烯生成的必要酸中心,且中强Brnsted酸中心更有利于异丁烯的生成,因此制备具有合适的中强Brnsted酸强度和酸分布的ZSM-35分子筛有利于正丁烯异构化反应的进行。展开更多
本文通过多相催化-仲氢诱导超极化(HET-PHIP)核磁共振(NMR)技术研究了Pd-Cu/SiO_2双金属催化剂上丙炔选择性加氢反应.首先利用等体积浸渍法和连续浸渍法合成了一系列不同Pd/Cu比例和形貌的Pd-Cu/SiO_2双金属催化剂.通过ALTADENA(Adiabat...本文通过多相催化-仲氢诱导超极化(HET-PHIP)核磁共振(NMR)技术研究了Pd-Cu/SiO_2双金属催化剂上丙炔选择性加氢反应.首先利用等体积浸渍法和连续浸渍法合成了一系列不同Pd/Cu比例和形貌的Pd-Cu/SiO_2双金属催化剂.通过ALTADENA(Adiabatic Longitudinal Transport After Dissociation Engenders Net Alignment)方法发现,催化剂的Pd/Cu比例和形貌均对PHIP的极化效率有较大影响.随着Pd-Cu双金属催化剂中Pd比例的增大,PHIP极化效率降低,同时反应活性增强.在同Pd/Cu比例下,相对于等体积浸渍法,连续浸渍法制备的层叠形貌催化剂具有较弱的极化效率以及较强的催化活性,这是由于催化剂表面暴露出的Pd数量增多,导致催化活性增强;同时单个Pd集簇表面积增大,使得氢原子移动范围扩大,从而造成极化效率降低.展开更多
Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclea...Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclear magnetic resonance(NMR) spectroscopy coupled with Raman and X-ray diffraction(XRD) techniques are employed to study the reaction mechanism in a soft carbon quantitatively.It is revealed that the insertion of potassium ions into the soft carbon firstly induces a transformation of the disordered region to short-range ordered stacking,involving both the pristine local unorganized and organized carbon layers.Subsequently,potassium ions intercalate into the rearranged carbon structure,finally producing the nano-sized KC_(8).Moreover,a remarkable c apacity of 322 mAh·g^(-1) with a low mid potassiation voltage of <0.3 V is present for the prepared soft carbon,which is on account of the underlying potassium storage sites,including the disordered stacking carbon as a main component of the soft carbon.These results suggest that regulating the disordered stacking region in the turbostratic structure of soft carbon is a critical issue for further improving the potassium storage performance.展开更多
本文首先利用等体积共浸渍法合成了一系列Pd/Sn比(原子比)不同的Pd_(1)-Sn_(x)/Al_(2)O_(3)双金属催化剂,然后通过多相催化仲氢诱导极化(PHIP)技术研究了Pd-Sn/Al_(2)O_(3)双金属催化剂上1,3-丁二烯选择性加氢反应.结果发现催化剂的Pd/S...本文首先利用等体积共浸渍法合成了一系列Pd/Sn比(原子比)不同的Pd_(1)-Sn_(x)/Al_(2)O_(3)双金属催化剂,然后通过多相催化仲氢诱导极化(PHIP)技术研究了Pd-Sn/Al_(2)O_(3)双金属催化剂上1,3-丁二烯选择性加氢反应.结果发现催化剂的Pd/Sn比会影响1,3-丁二烯反应活性和丁烯选择性:随着Pd/Sn比的下降,反应中1,3-丁二烯转化率降低,丁烯选择性提高.利用PASADENA(parahydrogen and synthesis allow for dramatically enhanced nuclear alignment)技术,发现Pd/Sn比的变化影响了1-丁烯与2-丁烯之间的异构化过程:随着Pd/Sn比的下降,1-丁烯异构化率降低,这是由于Sn组分含量的提高减少了表面暴露的Pd组分,使得催化剂反应活性降低;Sn组分含量的提高同时导致了Pd电子密度的上升,使得选择性还原产物丁烯更易脱附,阻止其进一步加氢生成丁烷,并抑制了1-丁烯异构化反应过程.展开更多
基金supported by the National Natural Science Foundation of China(No.21974007).
文摘Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.
基金supported by the National Natural Science Foundation of China(Nos.21922410,22072133,and 22275159)Zhejiang Provincial Natural Science Foundation(No.LR19B050001)Zhejiang Provincial Natural Science Foundation(No.LQ20H170002).
文摘Bone is a hierarchical architecture that consists of both inorganic and organic components.The organic components,including collagen and numerous non-collagenous biomolecules,are crucial for maintaining the mechanical strength and physiological functions of bone.The native structures of organic components and especially the mutual interactions between different components are important questions to be addressed.Among different analytical techniques,solid-state nuclear magnetic resonance(SSNMR)spectroscopy is a powerful tool to reveal the chemical and interactional information at an atomic level.Recent advancements of SSNMR technology and experimental protocols have brought great advances in understanding the molecular details in native bones.In this review,we summarize the progresses on the SSNMR studies of various organic components in the bone matrix.In the first part,we review the studies on collagen from four different aspects:(1)waterassociated molecular dynamics;(2)the intrahelical/interhelical interactions in collagen residues;(3)the interactions between collagen and citrate;and(4)the cross-linking between collagen and inorganic surface.In the second part,we review the studies on the non-protein biomolecules including sugar species,citrate,lipids,and nucleic acids.In the end,we propose an outlook of future directions for SSNMR investigations on bones.
文摘H 3PW 12O 40/SiO 2(PW/SiO 2) was prepar ed by the sol-gel method and trimethylolpropane tri-heptanoate(TMH ) was synthes ized by trimethylolpropane(TMP) and heptylic acid(HA) in the presence of H 3PW 12O 40/SiO 2.The results showed that the catalyst with 50%(mass)PW had good activity and stability.The optimal esterification conditions were as f ollows:n TMP∶n HA=1∶4,2%(mass)PW/SiO 2,reaction temperature 120—200 ℃ and 3 h.The structure of TMH was characterized by GC,IR, 1HNMR spectra and the rate of esterification was up to 95%.
文摘为了详尽定性和定量分析ZSM-35分子筛孔道内部和外部的酸中心,对在不同焙烧晶化条件下制备的3种ZSM-35分子筛样品(编号分别为GNJ,GNX,GW)采用NH3-TPD和吸附不同探针分子的31P MAS NMR谱进行表征,并在微反装置上对3种样品进行催化正丁烯异构化反应性能评价。结果表明:ZSM-35分子筛中Brnsted酸酸量远多于Lewis酸酸量,且不同制备方法得到的ZSM-35分子筛Brnsted酸强度与酸量不同;GNJ主要有1种弱Brnsted酸中心,GW有3种不同强度的Brnsted酸中心,较弱的Brnsted酸中心在孔道内部和外部均有分布,较强的两种Brnsted酸中心主要分布在孔道内部;GNX有两种不同强度的Brnsted酸中心,在孔道内部和外部均有分布,且GNX的Brnsted酸酸量高于GNJ和GW;催化正丁烯异构化反应时,ZSM-35分子筛的中强Brnsted酸中心是异丁烯生成的必要酸中心,且中强Brnsted酸中心更有利于异丁烯的生成,因此制备具有合适的中强Brnsted酸强度和酸分布的ZSM-35分子筛有利于正丁烯异构化反应的进行。
基金supported by the National Basic Research Program of China(973 Program,2013CB934800)the National Natural Science Foundation of China(21222302,20903056,21073083)+2 种基金the National Natural Science Foundation of China-Royal Society(NSFC-RS)Joint Project(21111130201)the Program for New Century Excellent Talents in University(NCET-10-0483)the Fundamental Research Funds for the Central Universities(1124020512)~~
文摘本文通过多相催化-仲氢诱导超极化(HET-PHIP)核磁共振(NMR)技术研究了Pd-Cu/SiO_2双金属催化剂上丙炔选择性加氢反应.首先利用等体积浸渍法和连续浸渍法合成了一系列不同Pd/Cu比例和形貌的Pd-Cu/SiO_2双金属催化剂.通过ALTADENA(Adiabatic Longitudinal Transport After Dissociation Engenders Net Alignment)方法发现,催化剂的Pd/Cu比例和形貌均对PHIP的极化效率有较大影响.随着Pd-Cu双金属催化剂中Pd比例的增大,PHIP极化效率降低,同时反应活性增强.在同Pd/Cu比例下,相对于等体积浸渍法,连续浸渍法制备的层叠形貌催化剂具有较弱的极化效率以及较强的催化活性,这是由于催化剂表面暴露出的Pd数量增多,导致催化活性增强;同时单个Pd集簇表面积增大,使得氢原子移动范围扩大,从而造成极化效率降低.
基金financially supported by the National Nature Science Foundation of China (Nos.21905314, 21825202,21733012,92045302 and 21603231)Newton Advanced Fellowships (No.NAF/R2/180603)+1 种基金"Scientist Studio Funding" from Tianmu Lake Institute of Advanced Energy Storage Technologies Co.,Ltdthe Science and Technology Service Network Initiative from Chinese Academy of Science (No.STS 2020T3022)。
文摘Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclear magnetic resonance(NMR) spectroscopy coupled with Raman and X-ray diffraction(XRD) techniques are employed to study the reaction mechanism in a soft carbon quantitatively.It is revealed that the insertion of potassium ions into the soft carbon firstly induces a transformation of the disordered region to short-range ordered stacking,involving both the pristine local unorganized and organized carbon layers.Subsequently,potassium ions intercalate into the rearranged carbon structure,finally producing the nano-sized KC_(8).Moreover,a remarkable c apacity of 322 mAh·g^(-1) with a low mid potassiation voltage of <0.3 V is present for the prepared soft carbon,which is on account of the underlying potassium storage sites,including the disordered stacking carbon as a main component of the soft carbon.These results suggest that regulating the disordered stacking region in the turbostratic structure of soft carbon is a critical issue for further improving the potassium storage performance.
文摘本文首先利用等体积共浸渍法合成了一系列Pd/Sn比(原子比)不同的Pd_(1)-Sn_(x)/Al_(2)O_(3)双金属催化剂,然后通过多相催化仲氢诱导极化(PHIP)技术研究了Pd-Sn/Al_(2)O_(3)双金属催化剂上1,3-丁二烯选择性加氢反应.结果发现催化剂的Pd/Sn比会影响1,3-丁二烯反应活性和丁烯选择性:随着Pd/Sn比的下降,反应中1,3-丁二烯转化率降低,丁烯选择性提高.利用PASADENA(parahydrogen and synthesis allow for dramatically enhanced nuclear alignment)技术,发现Pd/Sn比的变化影响了1-丁烯与2-丁烯之间的异构化过程:随着Pd/Sn比的下降,1-丁烯异构化率降低,这是由于Sn组分含量的提高减少了表面暴露的Pd组分,使得催化剂反应活性降低;Sn组分含量的提高同时导致了Pd电子密度的上升,使得选择性还原产物丁烯更易脱附,阻止其进一步加氢生成丁烷,并抑制了1-丁烯异构化反应过程.
