Anion exchange membrane fuel cells(AEMFCs) offer a sustainable energy solution with non-precious metal catalysts,reduced degradation,and fuel flexibility.However,the sluggish oxygen reduction reaction(ORR) at the cath...Anion exchange membrane fuel cells(AEMFCs) offer a sustainable energy solution with non-precious metal catalysts,reduced degradation,and fuel flexibility.However,the sluggish oxygen reduction reaction(ORR) at the cathode and durability concerns impede commercialization.To address these challenges,this study presents a dual-atomic SiFe-N-C catalyst derived from pinecones,a naturally abundant biomass resource.The catalyst features a nitrogen-rich porous carbon matrix that stabilizes Si-Fe dual-atomic sites during pyrolysis.Advanced analyses confirm Fe-Si and Fe-N bonds,which synergistically enhance ORR activity by optimizing electronic structures and intermediate adsorption energies.The SiFe-N-C catalyst surpasses Pt/C and Fe-N-C single-atom benchmarks with superior ORR activity and excellent long-term durability supported by high resistance to CO poisoning as well as methanol crossover.It also demonstrates a promising electrochemical performance as a catalytic material for the separator of Li-S battery.Mechanistic studies reveal that the Si-Fe dual-atomic configuration promotes an efficient Fe-O-O-Si pathway,reducing energy barriers and offering a cost-effective,high-performance solution for electrochemical energy conversion and storage applications.展开更多
Ammonia borane(NH_(3)BH_(3),AB)has been regarded as a promising chemical hydrogen storage material owing to its high hydrogen density and superior stability.Thus,the development of low-cost and high-efficient heteroge...Ammonia borane(NH_(3)BH_(3),AB)has been regarded as a promising chemical hydrogen storage material owing to its high hydrogen density and superior stability.Thus,the development of low-cost and high-efficient heterogeneous catalysts for the dehydrogenation of AB has attracted considerable scholarly attention.In this study,heterostructured Co_(3)O_(4)-SnO_(2)catalysts containing oxygen vacancy(V_(o))with different Co/Sn atomic ratios(designated as V_(o)-Co-Sn_(5:x))were synthesized via a simple coprecipitation-calcination method under mild reaction conditions.The catalyst containing an optimized Co/Sn atomic ratio of 5:2(V_(o)-Co-Sn_(5:2))exhibited robust catalytic performance with a turnover frequency value of 17.6mol_(H2)·mol^(-1)_(metal)·min^(-1).Moreover,82.6%of the original activity of the catalyst was retained after 14 catalytic cycles,indicating the high stability of the catalyst.Diversified characterization combined with the density functional theory(DFT)calculation confirmed the transfer of electrons from Co_(3)O_(4)to Sn O_(2)and the distribution of the separated charges on SnO_(2)-Co_(3)O_(4)interface.The transfer of electrons and the distribution of charges facilitated the adsorption and activation of water on the catalyst,thus accelerating the dissociation of H_(2)O molecule(the ratedetermining step of AB hydrolysis).It was found that the V_(o)adjusted the electron structure of the catalysts rather than acted as active sites.These findings will provide researchers with useful information for designing cheap and highly efficient catalysts for catalytic AB hydrolysis.展开更多
Carbon dioxide as a notorious greenhouse gas triggers severe global warming which is threatening the balance of ecosystem. In this respect, effectively capturing and transforming CO_(2)into value-added chemicals are e...Carbon dioxide as a notorious greenhouse gas triggers severe global warming which is threatening the balance of ecosystem. In this respect, effectively capturing and transforming CO_(2)into value-added chemicals are essential but still challenging tasks. As a kind of emerging crystalline porous material, covalent organic frameworks(COFs) have been demonstrated to be able to adsorb gases and function as catalysts to facilitate chemical transformations. Herein, we report an imine-linked, cobalt sandwich complex-based COF(Co-BD-COF) with high crystallinity and large surface area.Co-BD-COF can efficiently catalyze the transformation of CO_(2)into cyclic carbonates due to abundant metal sites and high porosity. In addition, Co-BD-COF exhibits high catalytic selectivity toward small ethylene oxide derivatives in cycloaddition reaction due to the large steric hindrance around the cobalt complexes rendered by the peripheral phenyl moieties.This new metal sandwich-type building block provides a new strategy for improving catalytic selectivity of COFs.展开更多
基金National Research Foundation of Korea (NRF)Ministry of Science and ICT,Grant/Award Number:RS-2024-00449682+2 种基金Korean government (MSIT),Grant/Award Numbers:RS-2025-00519449, RS-2023-00236572, RS-2022-NR072058KIST Institutional Program,Grant/Award Number:2E33940Korea Institute of Science and Technology Information (KISTI),Grant/Award Numbers:KSC-2023-CRE-0059, KSC-2023-CRE-0332, KSC-2023-CRE-0251, KSC-2023-CRE-0355。
文摘Anion exchange membrane fuel cells(AEMFCs) offer a sustainable energy solution with non-precious metal catalysts,reduced degradation,and fuel flexibility.However,the sluggish oxygen reduction reaction(ORR) at the cathode and durability concerns impede commercialization.To address these challenges,this study presents a dual-atomic SiFe-N-C catalyst derived from pinecones,a naturally abundant biomass resource.The catalyst features a nitrogen-rich porous carbon matrix that stabilizes Si-Fe dual-atomic sites during pyrolysis.Advanced analyses confirm Fe-Si and Fe-N bonds,which synergistically enhance ORR activity by optimizing electronic structures and intermediate adsorption energies.The SiFe-N-C catalyst surpasses Pt/C and Fe-N-C single-atom benchmarks with superior ORR activity and excellent long-term durability supported by high resistance to CO poisoning as well as methanol crossover.It also demonstrates a promising electrochemical performance as a catalytic material for the separator of Li-S battery.Mechanistic studies reveal that the Si-Fe dual-atomic configuration promotes an efficient Fe-O-O-Si pathway,reducing energy barriers and offering a cost-effective,high-performance solution for electrochemical energy conversion and storage applications.
基金financially supported by the Professorial and Doctoral Scientific Research Foundation of Huizhou University(Nos.2018JB036,2020JB046 and 2022JB009)the Major and Special Project in the Field of Intelligent Manufacturing of the Universities in Guangdong Province(No.2020ZDZX2067)+3 种基金the Natural Science Foundation of Huizhou University(No.HZU202004)Open Project Program of Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices,Huizhou University(Nos.EFMDN2021001Z and EFMDN2021004M)Youth Innovative Talents Project in Collegesand Universities in Guangdong Province(No.2019KQNCX151)Basic and Applied Basic Research Fund of Guangdong Province(No.2020A1515110038)。
文摘Ammonia borane(NH_(3)BH_(3),AB)has been regarded as a promising chemical hydrogen storage material owing to its high hydrogen density and superior stability.Thus,the development of low-cost and high-efficient heterogeneous catalysts for the dehydrogenation of AB has attracted considerable scholarly attention.In this study,heterostructured Co_(3)O_(4)-SnO_(2)catalysts containing oxygen vacancy(V_(o))with different Co/Sn atomic ratios(designated as V_(o)-Co-Sn_(5:x))were synthesized via a simple coprecipitation-calcination method under mild reaction conditions.The catalyst containing an optimized Co/Sn atomic ratio of 5:2(V_(o)-Co-Sn_(5:2))exhibited robust catalytic performance with a turnover frequency value of 17.6mol_(H2)·mol^(-1)_(metal)·min^(-1).Moreover,82.6%of the original activity of the catalyst was retained after 14 catalytic cycles,indicating the high stability of the catalyst.Diversified characterization combined with the density functional theory(DFT)calculation confirmed the transfer of electrons from Co_(3)O_(4)to Sn O_(2)and the distribution of the separated charges on SnO_(2)-Co_(3)O_(4)interface.The transfer of electrons and the distribution of charges facilitated the adsorption and activation of water on the catalyst,thus accelerating the dissociation of H_(2)O molecule(the ratedetermining step of AB hydrolysis).It was found that the V_(o)adjusted the electron structure of the catalysts rather than acted as active sites.These findings will provide researchers with useful information for designing cheap and highly efficient catalysts for catalytic AB hydrolysis.
基金supported by the National Natural Science Foundation of China (51973153 and 21704065)the National Key Research and Development Program of China (2017YFA0207500)+1 种基金Guangdong Basic and Applied Basic Research Foundation (2021A1515010228)the Innovation Research Foundation of Shenzhen (JCYJ20190808115215125)。
文摘Carbon dioxide as a notorious greenhouse gas triggers severe global warming which is threatening the balance of ecosystem. In this respect, effectively capturing and transforming CO_(2)into value-added chemicals are essential but still challenging tasks. As a kind of emerging crystalline porous material, covalent organic frameworks(COFs) have been demonstrated to be able to adsorb gases and function as catalysts to facilitate chemical transformations. Herein, we report an imine-linked, cobalt sandwich complex-based COF(Co-BD-COF) with high crystallinity and large surface area.Co-BD-COF can efficiently catalyze the transformation of CO_(2)into cyclic carbonates due to abundant metal sites and high porosity. In addition, Co-BD-COF exhibits high catalytic selectivity toward small ethylene oxide derivatives in cycloaddition reaction due to the large steric hindrance around the cobalt complexes rendered by the peripheral phenyl moieties.This new metal sandwich-type building block provides a new strategy for improving catalytic selectivity of COFs.
