Lithium sulfur batteries(LSBs)show great promise as next-generation batteries due to their high energy density.However,commercialization is hindered by limited cycle life,fast capacity decay and poor sulfur utilizatio...Lithium sulfur batteries(LSBs)show great promise as next-generation batteries due to their high energy density.However,commercialization is hindered by limited cycle life,fast capacity decay and poor sulfur utilization,primarily due to the intricate phase evolution during battery operation and insulating characteristics of sulfur,leading to uncontrollable sulfur and polysulfide distribution and inefficient conversion kinetics.Therefore,the incorporation of metal and covalent organic frameworks(MOFs and COFs)has been widely employed in LSBs to serve as hosts,enabling the regulation of conversion and diffusion behavior of vip species,including lithium ions,sulfur and polysulfides,within their well-defined nanosized cavities.Nevertheless,pristine frameworks often fail to meet the requisite standards,and framework functionalization offers unique opportunities to tailor desired attributes and facilitate selective host-vip interactions in LSBs.However,a thorough understanding on how to precisely customize the nano-channels with functional groups to promote such interactions remains largely unexplored.In this review,we provide a systematic discussion on how the grafting of functional groups containing various active sites can play a role in host-vip chemistry,and focus on the latest advancements in engineering functionalized MOFs and COFs as charged-species regulators to tackle the problems causing poor LSB electrochemical performance.The concepts of electrophilic and nucleophilic effects are proposed,uncovering the mechanisms of framework functionalization in LSBs and serving as guidance for future developments.展开更多
Metal-organic frameworks（MOFs） are a unique class of porous crystalline materials that have shown promise for a wide range of applications. MOFs have been explored as a new type of heterogeneous catalytic materials,...Metal-organic frameworks（MOFs） are a unique class of porous crystalline materials that have shown promise for a wide range of applications. MOFs have been explored as a new type of heterogeneous catalytic materials, because of their high surface area, uniform and tunable pores, facile functionalization and incorporation of catalytic active sites. The use of multi-functional sites MOF materials as catalysts for synergistic catalysis and tandem reactions has attracted increasing attention. In this review, we aim to introduce the construction of bi-or multi-functional MOF catalysts with cooperative or cascade functions via post-synthetic modification（PSM）.展开更多
Multivariate metal-organic frameworks（MTV-MOFs） with different ratios of terephthalate（BDC） linker and amino-benzenedicarboxylate（BDC-NH2） linker were synthesized through both direct synthesis from linker mixtur...Multivariate metal-organic frameworks（MTV-MOFs） with different ratios of terephthalate（BDC） linker and amino-benzenedicarboxylate（BDC-NH2） linker were synthesized through both direct synthesis from linker mixture and linker exchange of activated single-linker MOFs. Functionality proportion was impacted by the thermodynamics during the one-pot MOF construction, resulting in preference of BDC over BDC-NH2 in the MTV-MOF, in agreement with the quantum mechanics calculations. The functionality difference also affects the thermodynamics in the linker exchange process, as indicated by the more effective linker exchange in BDC-NH2-based IRMOF-3 than in BDC-based MOF-5. Furthermore,the thermal decomposition temperatures and chemical integrity upon ambient air exposure of these MOFs with variate functionalities were investigated, and it reveals that higher proportion of BDC in the MTV-MOF crystals contribute to both higher thermal and higher chemical stabilities.展开更多
基金supported by the Singapore Ministry of Education,and the National Research Foundation(NRF)for research conducted at the National University of Singapore(CRP NRF-CRP26-2021-0003).
文摘Lithium sulfur batteries(LSBs)show great promise as next-generation batteries due to their high energy density.However,commercialization is hindered by limited cycle life,fast capacity decay and poor sulfur utilization,primarily due to the intricate phase evolution during battery operation and insulating characteristics of sulfur,leading to uncontrollable sulfur and polysulfide distribution and inefficient conversion kinetics.Therefore,the incorporation of metal and covalent organic frameworks(MOFs and COFs)has been widely employed in LSBs to serve as hosts,enabling the regulation of conversion and diffusion behavior of vip species,including lithium ions,sulfur and polysulfides,within their well-defined nanosized cavities.Nevertheless,pristine frameworks often fail to meet the requisite standards,and framework functionalization offers unique opportunities to tailor desired attributes and facilitate selective host-vip interactions in LSBs.However,a thorough understanding on how to precisely customize the nano-channels with functional groups to promote such interactions remains largely unexplored.In this review,we provide a systematic discussion on how the grafting of functional groups containing various active sites can play a role in host-vip chemistry,and focus on the latest advancements in engineering functionalized MOFs and COFs as charged-species regulators to tackle the problems causing poor LSB electrochemical performance.The concepts of electrophilic and nucleophilic effects are proposed,uncovering the mechanisms of framework functionalization in LSBs and serving as guidance for future developments.
基金supported by the National Natural Science Foundation of China (Nos. 21371069 and 21621001)
文摘Metal-organic frameworks（MOFs） are a unique class of porous crystalline materials that have shown promise for a wide range of applications. MOFs have been explored as a new type of heterogeneous catalytic materials, because of their high surface area, uniform and tunable pores, facile functionalization and incorporation of catalytic active sites. The use of multi-functional sites MOF materials as catalysts for synergistic catalysis and tandem reactions has attracted increasing attention. In this review, we aim to introduce the construction of bi-or multi-functional MOF catalysts with cooperative or cascade functions via post-synthetic modification（PSM）.
基金supported by the "Top-Notch Students Training in Basic Disciplines" undergraduate program of Ministry of Education of China
文摘Multivariate metal-organic frameworks（MTV-MOFs） with different ratios of terephthalate（BDC） linker and amino-benzenedicarboxylate（BDC-NH2） linker were synthesized through both direct synthesis from linker mixture and linker exchange of activated single-linker MOFs. Functionality proportion was impacted by the thermodynamics during the one-pot MOF construction, resulting in preference of BDC over BDC-NH2 in the MTV-MOF, in agreement with the quantum mechanics calculations. The functionality difference also affects the thermodynamics in the linker exchange process, as indicated by the more effective linker exchange in BDC-NH2-based IRMOF-3 than in BDC-based MOF-5. Furthermore,the thermal decomposition temperatures and chemical integrity upon ambient air exposure of these MOFs with variate functionalities were investigated, and it reveals that higher proportion of BDC in the MTV-MOF crystals contribute to both higher thermal and higher chemical stabilities.
