Hydrogen isotope separation is a challenging task due to their similar properties.Herein,based on the chemical affinity quantum sieve(CAQS)effect,the D_(2)/H_(2)separation performance of M_(2)(m-dobdc)(M=Co,Ni,Mg,Mn;m...Hydrogen isotope separation is a challenging task due to their similar properties.Herein,based on the chemical affinity quantum sieve(CAQS)effect,the D_(2)/H_(2)separation performance of M_(2)(m-dobdc)(M=Co,Ni,Mg,Mn;m-dobdc^(4-)=4,6-dioxido-1,3-benzenedicarboxylate),a series of honeycomb-shaped MOFs with high stability and abundant open metal sites,are studied by gases sorption and breakthrough experiments,in which two critical factors,gas uptake and adsorption enthalpy,are taken into consideration.Among these MOFs,Co_(2)(m-dobdc)exhibits the longest D_(2)retention time of 180 min/g(H_(2)/D_(2)/Ne:1/1/98)at 77 K because of its second-highest adsorption enthalpy(10.7 kJ/mol for H_(2)and 11.8 kJ/mol for D_(2))and the best sorption capacity(5.22 mmol/g for H_(2)and 5.49 mmol/g for D_(2))under low pressure of 1 kPa and 77 K,which make it a promising material for industrial hydrogen isotope separation.Moreover,the results indicate that H_(2)and D_(2)capacities under low pressure(about 1 kPa)dominate the final D_(2)/H_(2)separation property of MOFs.展开更多
Porous organic cages(POCs)have shown great potential in many applications,and post-synthetic modification(PSM)has been confirmed to be an effective strategy to tailor their structures and related functionalities.Howev...Porous organic cages(POCs)have shown great potential in many applications,and post-synthetic modification(PSM)has been confirmed to be an effective strategy to tailor their structures and related functionalities.However,it is extremely challenging to develop a general platform for simple-to-make functional POCs for advanced applications by PSM method.Herein,we reported that octahedral calix[4]resorcinarene-based hydrazone-linked porous organic cage(HPOC-401)provides an excellent platform for post-synthetic metalation by various transition metal(TM)ions under mild conditions due to the abundance of coordination sites in its skeleton.Such metalated products(HPOC-401-TM)exhibit Brunauer-Emmett-Teller(BET)surface area up to1,456 m^(2)g^(-1),much higher than that of the pristine HPOC-401,which has a BET value of 474 m^(2)g^(-1).Moreover,the metalation and porosity increases further influence their gas capture,separation,as well as catalytic performance.For instance,HPOC-401-TM products exhibit higher CO_(2),H_(2),and C2 hydrocarbon gas uptake,as well as higher C_(2)H_(6)/C_(2)H_(4) selectivity than HPOC-401.Moreover,the HPOC-401-TM also shows better catalytic performance in the cycloaddition of CO_(2) with epoxides compared to HPOC-401.These findings uncover a simple yet effective approach for modifying the porosity characteristics of organic cages,which will undoubtedly expand their future implementations.展开更多
It is extremely challenging to construct three-dimensional(3D)crystalline covalent organic frameworks(COFs)with flexible building blocks and to further explore their tunable or adaptive characteristics due to crystall...It is extremely challenging to construct three-dimensional(3D)crystalline covalent organic frameworks(COFs)with flexible building blocks and to further explore their tunable or adaptive characteristics due to crystallization and structure determination difficulties.Herein,we constructed three crystalline isostructural 3D-OC-COFs based on a newly synthesized flexible organic cage(6NH_(2)-OC.4HCl)through a novel in situ acid–base neutralization strategy.展开更多
The unique adsorption performance of metal-organic frameworks(MOFs) indicates a new direction for gas separation and purification. The low-temperature distillation, as a traditional technique for hydrogen isotope sepa...The unique adsorption performance of metal-organic frameworks(MOFs) indicates a new direction for gas separation and purification. The low-temperature distillation, as a traditional technique for hydrogen isotope separation, is limited as it is a high energy-and cost-intensive process. Instead of utilizing such a conventional separation route, we use ordered microporous frameworks based on a physical adsorption mechanism to solve the challenge of hydrogen isotope separation. Herein we analyze M-MOF-74(M=Co, Ni, Mg, Zn), featuring a hexagonal channel about 11 ? and high density of open metal sites, for their ability to separate and purify deuterium from the hydrogen isotope mixture by dynamic column breakthrough experiments. Our results show that the combination of the strength of binding sites, density of coordinatively unsaturated metal sites and hydrogen isotope adsorption capacity of materials renders Co-MOF-74 as an optimal adsorbent for the capture of deuterium from hydrogen isotope mixtures in a simulated industrial process.展开更多
The exploration of ethane(C_(2)H_(6))-selective porous materials for the direct production of polymer-grade ethylene(C_(2)H_(4))from a C_(2)H_(6)/C_(2)H_(4) mixture in a single energy-saving adsorption step is of utmo...The exploration of ethane(C_(2)H_(6))-selective porous materials for the direct production of polymer-grade ethylene(C_(2)H_(4))from a C_(2)H_(6)/C_(2)H_(4) mixture in a single energy-saving adsorption step is of utmost importance but remains a significant challenge.Thus,developing robust C_(2)H_(6)-selective adsorbents with high C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity is urgently needed for industrial applications.In this study,we have successfully designed and synthesized two novel calix[4]resorcinarene-based porous organic cages(POCs)named CPOC-501 and CPOC-502.The POCs were formed via a Schiff-base reaction involving face-directed[6+8]condensation between a bowlshaped tetratopic tetraformylcalix[4]resorcinarene and triangular tritopic amine synthons.Analysis using single crystal X-ray crystallography revealed that both cages possess large truncated octahedral cavities with a volume of approximately 6500Å3 and 12 accessible rhombic windows with a side length of approximately 10.5Å.Furthermore,the cages exhibited excellent chemical stability under neutral,acidic,and basic conditions and high Brunauer–Emmett–Teller specific surface areas of up to 2175 m^(2) g^(−1) after desolvation.Both POCs demonstrated superior adsorption capabilities for C_(2)H_(6) over C_(2)H_(4).Notably,CPOC-502 exhibited a C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity of 83 cm^(3) g^(−1) and 2.83,respectively,surpassing most of the best-performing C_(2)H_(6)-selective porous organic materials reported to date.Moreover,breakthrough experiments confirmed that both cages efficiently produced polymer-grade C_(2)H_(4)(>99.9%)directly from the C_(2)H_(6)/C_(2)H_(4) mixture,highlighting their outstanding recyclability.展开更多
基金financially supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB20000000)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(No.QYZDB-SSW-SLH019)the National Natural Science Foundation of China(Nos.21771177,51603206 and 21203117).
文摘Hydrogen isotope separation is a challenging task due to their similar properties.Herein,based on the chemical affinity quantum sieve(CAQS)effect,the D_(2)/H_(2)separation performance of M_(2)(m-dobdc)(M=Co,Ni,Mg,Mn;m-dobdc^(4-)=4,6-dioxido-1,3-benzenedicarboxylate),a series of honeycomb-shaped MOFs with high stability and abundant open metal sites,are studied by gases sorption and breakthrough experiments,in which two critical factors,gas uptake and adsorption enthalpy,are taken into consideration.Among these MOFs,Co_(2)(m-dobdc)exhibits the longest D_(2)retention time of 180 min/g(H_(2)/D_(2)/Ne:1/1/98)at 77 K because of its second-highest adsorption enthalpy(10.7 kJ/mol for H_(2)and 11.8 kJ/mol for D_(2))and the best sorption capacity(5.22 mmol/g for H_(2)and 5.49 mmol/g for D_(2))under low pressure of 1 kPa and 77 K,which make it a promising material for industrial hydrogen isotope separation.Moreover,the results indicate that H_(2)and D_(2)capacities under low pressure(about 1 kPa)dominate the final D_(2)/H_(2)separation property of MOFs.
基金supported by the National Natural Science Foundation of China(22071244)the Youth Innovation Promotion Association CAS(2022305)+1 种基金the Natural Science Foundation of Fujian Province of China(2022J01503,2020J05087)the China Postdoctoral Science Foundation(2020M671954)。
文摘Porous organic cages(POCs)have shown great potential in many applications,and post-synthetic modification(PSM)has been confirmed to be an effective strategy to tailor their structures and related functionalities.However,it is extremely challenging to develop a general platform for simple-to-make functional POCs for advanced applications by PSM method.Herein,we reported that octahedral calix[4]resorcinarene-based hydrazone-linked porous organic cage(HPOC-401)provides an excellent platform for post-synthetic metalation by various transition metal(TM)ions under mild conditions due to the abundance of coordination sites in its skeleton.Such metalated products(HPOC-401-TM)exhibit Brunauer-Emmett-Teller(BET)surface area up to1,456 m^(2)g^(-1),much higher than that of the pristine HPOC-401,which has a BET value of 474 m^(2)g^(-1).Moreover,the metalation and porosity increases further influence their gas capture,separation,as well as catalytic performance.For instance,HPOC-401-TM products exhibit higher CO_(2),H_(2),and C2 hydrocarbon gas uptake,as well as higher C_(2)H_(6)/C_(2)H_(4) selectivity than HPOC-401.Moreover,the HPOC-401-TM also shows better catalytic performance in the cycloaddition of CO_(2) with epoxides compared to HPOC-401.These findings uncover a simple yet effective approach for modifying the porosity characteristics of organic cages,which will undoubtedly expand their future implementations.
基金supported by the National Key R&D Program of China(no.2017YFA0700102)the National Natural Science Foundation of China(nos.22071244 and 21771177)+2 种基金the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(no.QYZDB-SSWSLH019)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(no.2021ZZ106)the Advanced Energy Science and Technology Guangdong Laboratory.
文摘It is extremely challenging to construct three-dimensional(3D)crystalline covalent organic frameworks(COFs)with flexible building blocks and to further explore their tunable or adaptive characteristics due to crystallization and structure determination difficulties.Herein,we constructed three crystalline isostructural 3D-OC-COFs based on a newly synthesized flexible organic cage(6NH_(2)-OC.4HCl)through a novel in situ acid–base neutralization strategy.
基金supported by the National Natural Science Foundation of China (21771177)the Strategic Priority Research Program of Chinese Academy of Sciences (XDB20000000)the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (QYZDB-SSW-SLH019)。
文摘The unique adsorption performance of metal-organic frameworks(MOFs) indicates a new direction for gas separation and purification. The low-temperature distillation, as a traditional technique for hydrogen isotope separation, is limited as it is a high energy-and cost-intensive process. Instead of utilizing such a conventional separation route, we use ordered microporous frameworks based on a physical adsorption mechanism to solve the challenge of hydrogen isotope separation. Herein we analyze M-MOF-74(M=Co, Ni, Mg, Zn), featuring a hexagonal channel about 11 ? and high density of open metal sites, for their ability to separate and purify deuterium from the hydrogen isotope mixture by dynamic column breakthrough experiments. Our results show that the combination of the strength of binding sites, density of coordinatively unsaturated metal sites and hydrogen isotope adsorption capacity of materials renders Co-MOF-74 as an optimal adsorbent for the capture of deuterium from hydrogen isotope mixtures in a simulated industrial process.
基金financially supported by the National Nature Science Foundation of China(grant nos.22071244 and 22275191)the Youth Innovation Promotion Association CAS(grant no.2022305)the Natural Science Foundation of Fujian Province of China(grant nos.2022J01503,2020J05087,and 2022I0037).
文摘The exploration of ethane(C_(2)H_(6))-selective porous materials for the direct production of polymer-grade ethylene(C_(2)H_(4))from a C_(2)H_(6)/C_(2)H_(4) mixture in a single energy-saving adsorption step is of utmost importance but remains a significant challenge.Thus,developing robust C_(2)H_(6)-selective adsorbents with high C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity is urgently needed for industrial applications.In this study,we have successfully designed and synthesized two novel calix[4]resorcinarene-based porous organic cages(POCs)named CPOC-501 and CPOC-502.The POCs were formed via a Schiff-base reaction involving face-directed[6+8]condensation between a bowlshaped tetratopic tetraformylcalix[4]resorcinarene and triangular tritopic amine synthons.Analysis using single crystal X-ray crystallography revealed that both cages possess large truncated octahedral cavities with a volume of approximately 6500Å3 and 12 accessible rhombic windows with a side length of approximately 10.5Å.Furthermore,the cages exhibited excellent chemical stability under neutral,acidic,and basic conditions and high Brunauer–Emmett–Teller specific surface areas of up to 2175 m^(2) g^(−1) after desolvation.Both POCs demonstrated superior adsorption capabilities for C_(2)H_(6) over C_(2)H_(4).Notably,CPOC-502 exhibited a C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity of 83 cm^(3) g^(−1) and 2.83,respectively,surpassing most of the best-performing C_(2)H_(6)-selective porous organic materials reported to date.Moreover,breakthrough experiments confirmed that both cages efficiently produced polymer-grade C_(2)H_(4)(>99.9%)directly from the C_(2)H_(6)/C_(2)H_(4) mixture,highlighting their outstanding recyclability.
