Rechargeable zinc-air batteries(ZABs)are currently receiving extensive attention because of their extremely high theoretical specific energy density,low manufacturing costs,and environmental friendliness.Exploring bif...Rechargeable zinc-air batteries(ZABs)are currently receiving extensive attention because of their extremely high theoretical specific energy density,low manufacturing costs,and environmental friendliness.Exploring bifunctional catalysts with high activity and stability to overcome sluggish kinetics of oxygen reduction reaction and oxygen evolution reaction is critical for the development of rechargeable ZABs.Atomically dispersed metal-nitrogen-carbon(M-N-C)catalysts possessing prominent advantages of high metal atom utilization and electrocatalytic activity are promising candidates to promote oxygen electrocatalysis.In this work,general principles for designing atomically dispersed M-N-C are reviewed.Then,strategies aiming at enhancing the bifunctional catalytic activity and stability are presented.Finally,the challenges and perspectives of M-N-C bifunctional oxygen catalysts for ZABs are outlined.It is expected that this review will provide insights into the targeted optimization of atomically dispersed M-N-C catalysts in rechargeable ZABs.展开更多
NiFe composites have been regarded as promising candidates to replace commercial noble-based electrocatalysts for the oxygen evolution reaction(OER).However,their practical applications still suffer from poor conducti...NiFe composites have been regarded as promising candidates to replace commercial noble-based electrocatalysts for the oxygen evolution reaction(OER).However,their practical applications still suffer from poor conductivity,limited activity,durability.To address these issues,herein,by utilizing three-dimensional covalent organic framework(3D-COF)with porous confined structures and abundant coordinate N sites as the precursor,the partially oxidized Ni_(3)Fe nanoalloys wrapped by Ndoped carbon(N-C)layers are constructed via simple pyrolysis and subsequent oxidization.Benefiting from the 3D curved hierarchical structure,high-conductivity of Ni_(3)Fe and N-C layers,well-distributed active sites,the as-synthesized O-Ni_(3)Fe-NC catalyst demonstrates excellent activity and durability for catalyzing OER.Experimental and theoretical analyses disclose that both high-temperature oxidization and the OER process greatly promote the formation and exposure of the Ni(Fe)OOH active species as well as lower charge transfer resistance,inducing its optimized OER activity.The robust graphitized N-C layers with superior conductivity and their couplings with oxidized Ni_(3)Fe nanoalloys are beneficial for stabilizing catalytic centers,thereby imparting O-Ni_(3)Fe-N-C with such outstanding stability.This work not only provides a rational guidance for enriching and stabilizing high-activity catalytic sites towards OER but also offers more insights into the structural evolution of NiFe-based OER catalysts.展开更多
基金This work is supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)Centre Québéco is sur les Materiaux Fonctionnels(CQMF),Fonds de Recherche du Québec-Nature et Technologies(FRQNT)+2 种基金Institut National de la Recherche Scientifique(INRS)This work is also supported by the National Natural Science Foundation of China(21972017)the“Scientific and Technical Innovation Action Plan”Hong Kong,Macao and Taiwan Science&Technology Cooperation Project of Shanghai Science and Technology Committee(19160760600).F.Dong gratefully acknowledges scholarships from the China Scholarship Council(CSC).
文摘Rechargeable zinc-air batteries(ZABs)are currently receiving extensive attention because of their extremely high theoretical specific energy density,low manufacturing costs,and environmental friendliness.Exploring bifunctional catalysts with high activity and stability to overcome sluggish kinetics of oxygen reduction reaction and oxygen evolution reaction is critical for the development of rechargeable ZABs.Atomically dispersed metal-nitrogen-carbon(M-N-C)catalysts possessing prominent advantages of high metal atom utilization and electrocatalytic activity are promising candidates to promote oxygen electrocatalysis.In this work,general principles for designing atomically dispersed M-N-C are reviewed.Then,strategies aiming at enhancing the bifunctional catalytic activity and stability are presented.Finally,the challenges and perspectives of M-N-C bifunctional oxygen catalysts for ZABs are outlined.It is expected that this review will provide insights into the targeted optimization of atomically dispersed M-N-C catalysts in rechargeable ZABs.
基金the National Natural Science Foundation of China(Nos.22075062 and 21871167)and the Volkswagen Foundation(Freigeist Fellowship)。
文摘NiFe composites have been regarded as promising candidates to replace commercial noble-based electrocatalysts for the oxygen evolution reaction(OER).However,their practical applications still suffer from poor conductivity,limited activity,durability.To address these issues,herein,by utilizing three-dimensional covalent organic framework(3D-COF)with porous confined structures and abundant coordinate N sites as the precursor,the partially oxidized Ni_(3)Fe nanoalloys wrapped by Ndoped carbon(N-C)layers are constructed via simple pyrolysis and subsequent oxidization.Benefiting from the 3D curved hierarchical structure,high-conductivity of Ni_(3)Fe and N-C layers,well-distributed active sites,the as-synthesized O-Ni_(3)Fe-NC catalyst demonstrates excellent activity and durability for catalyzing OER.Experimental and theoretical analyses disclose that both high-temperature oxidization and the OER process greatly promote the formation and exposure of the Ni(Fe)OOH active species as well as lower charge transfer resistance,inducing its optimized OER activity.The robust graphitized N-C layers with superior conductivity and their couplings with oxidized Ni_(3)Fe nanoalloys are beneficial for stabilizing catalytic centers,thereby imparting O-Ni_(3)Fe-N-C with such outstanding stability.This work not only provides a rational guidance for enriching and stabilizing high-activity catalytic sites towards OER but also offers more insights into the structural evolution of NiFe-based OER catalysts.
