Chiral metal-organic frameworks(CMOFs),an emerging class of heterogeneous chiral catalysts,show significant potential for application in asymmetric catalysis due to their tunable pore shapes and sizes,large internal s...Chiral metal-organic frameworks(CMOFs),an emerging class of heterogeneous chiral catalysts,show significant potential for application in asymmetric catalysis due to their tunable pore shapes and sizes,large internal surface areas,and rich chiral environments[1-4].Through over 20 years of development,researchers have invested heavily in exploring new CMOFs to enhance asymmetric catalytic performance[5-10].However,the dual pursuit of a substantial specific surface area and robust stability within a single CMOF presents a considerable challenge.Additionally,efficient CMOF catalysts,frequently synthesized from privileged chiral ligands such as proline,2,2'-bis(diphenylphosphino)-1,1'-binaph thyl(BINAP),Salen,and bis(oxazoline)(Box)[11,12],tend to exhibit more complex structures compared to their corresponding privileged chiral counterparts,thereby necessitating higher production costs.Consequently,the development of novel synthetic methodologies for constructing CMOFs as effective chiral catalysts remains a challenging endeavor.展开更多
Biochar with a highly accessible specific surface area can display a higher performance when it is used as the cathode of lithium-ion capacitors.Facing the complex composition and diversity of biomass precursors,there...Biochar with a highly accessible specific surface area can display a higher performance when it is used as the cathode of lithium-ion capacitors.Facing the complex composition and diversity of biomass precursors,there is a lack of a universally applicable method to construct hierarchical porous biochar controllably.In this work,a multi-stage activation strategy combining the feature of different activation methods is proposed for this target.To confirm the porous characteristic in prepared samples,N_(2) adsorption-desorption and transmission electron microscope were used.As the optimal sample,BC-P3K4S had the highest specific surface area of 3583.3 m^(2) g^(−1).Evaluated as the electrode for a lithium-ion capacitor,BC-P3K4S displayed a capacity of 139.1 mAh g^(−1) at 0.1 A g^(−1).After coupling it with pre-lithiated hard carbon,the full device exhibited a high energy density of 129.3 W h kg^(−1) at 153 W kg^(−1).The work outlined herein offers some insights into the preparation of hierarchical porous biochar from complex biomass by multistep activation method.展开更多
基金supported by the National Key R&D Program of China(2022YFA1503300)and the National Natural Science Foundation of China(21971241 and 21935010)。
文摘Chiral metal-organic frameworks(CMOFs),an emerging class of heterogeneous chiral catalysts,show significant potential for application in asymmetric catalysis due to their tunable pore shapes and sizes,large internal surface areas,and rich chiral environments[1-4].Through over 20 years of development,researchers have invested heavily in exploring new CMOFs to enhance asymmetric catalytic performance[5-10].However,the dual pursuit of a substantial specific surface area and robust stability within a single CMOF presents a considerable challenge.Additionally,efficient CMOF catalysts,frequently synthesized from privileged chiral ligands such as proline,2,2'-bis(diphenylphosphino)-1,1'-binaph thyl(BINAP),Salen,and bis(oxazoline)(Box)[11,12],tend to exhibit more complex structures compared to their corresponding privileged chiral counterparts,thereby necessitating higher production costs.Consequently,the development of novel synthetic methodologies for constructing CMOFs as effective chiral catalysts remains a challenging endeavor.
基金National Natural Science Foundation of China(51976234)Forestry technology projects of Zhejiang Province(2023SY04)+1 种基金Foundation of Jiangsu Key Lab of Biomass Energy and Material(JSBEM-S-202101)National Nonprofit Institute Research Grant of Chinese Academy of Forestry(CAFYBB2020ZF001).
文摘Biochar with a highly accessible specific surface area can display a higher performance when it is used as the cathode of lithium-ion capacitors.Facing the complex composition and diversity of biomass precursors,there is a lack of a universally applicable method to construct hierarchical porous biochar controllably.In this work,a multi-stage activation strategy combining the feature of different activation methods is proposed for this target.To confirm the porous characteristic in prepared samples,N_(2) adsorption-desorption and transmission electron microscope were used.As the optimal sample,BC-P3K4S had the highest specific surface area of 3583.3 m^(2) g^(−1).Evaluated as the electrode for a lithium-ion capacitor,BC-P3K4S displayed a capacity of 139.1 mAh g^(−1) at 0.1 A g^(−1).After coupling it with pre-lithiated hard carbon,the full device exhibited a high energy density of 129.3 W h kg^(−1) at 153 W kg^(−1).The work outlined herein offers some insights into the preparation of hierarchical porous biochar from complex biomass by multistep activation method.
