CONSPECTUS:Due to the overuse of fossil fuels,various detrimental effects along with the excess CO_(2)emissions have induced global warming and sea-level rising.To tackle climate change and provide a cleaner environme...CONSPECTUS:Due to the overuse of fossil fuels,various detrimental effects along with the excess CO_(2)emissions have induced global warming and sea-level rising.To tackle climate change and provide a cleaner environment for the air we breathe and water we consume,the existing energy mix needs to be changed into fossil-free,clean,renewable energy with zero emission(e.g.,fuel cells).While providing a promising and scalable strategy to the energy and environmental challenges,renewable energy processes often involve noble-metal-based catalysts(i.e.,Pt,RuO_(2)).However,the disadvantages of noblemetal-based catalysts,including their high cost and scarcity,have hampered the large-scale application of renewable energy technologies.In 2009,we discovered earth-abundant carbon materials functioning as efficient low-cost,carbon-based metal-free electrocatalysts(C-MFECs)attractive for renewable energy and environmental remediation.Since then,C-MFECs have become an emerging new research field over the world.They are demonstrated to be efficient multifunctional catalysts for various key reactions important to renewable energy and environmental technologies,including oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),oxygen evolution reaction(OER),CO_(2)reduction reaction(CO_(2)RR),and N_(2)reduction reaction(NRR),to name a few.Charge transfer/redistribution induced by heteroatom(e.g.,N)and/or defect doping was recognized as the driving force for the metal-free catalytic activities.This finding has been used as a guidance to design and develop various new and multifunctional C-MFECs for many reactions even beyond the renewable energy and environmental remediation.In this Account,we first summarize our previous work on the development and mechanistic understanding of C-MFECs for ORR,HER,and OER to promote renewable energy conversion and storage.Then,we present recent advances in C-MFECs for new important reactions for environment remediation(e.g.,CO_(2)RR,NRR),seawater splitting,and metal−CO_(2)batteries.However,different dopant locations for C-MFECs even with the same doping element and content can cause variable catalytic properties for heteroatom-doped carbon materials.Therefore,vast opportunities remain for further developing numerous innovative C-MFECs with defined structures to gain a better understanding of their structure-based properties.In this context,we finally conclude with the current challenges and future perspectives in this exciting field.展开更多
Recently,carbon-based metal-free electrocatalysts(C‐MFECs)have drawn considerable research attention because of their attractive physicochemical characteristics,cost-effectiveness,and ability to convert and store ene...Recently,carbon-based metal-free electrocatalysts(C‐MFECs)have drawn considerable research attention because of their attractive physicochemical characteristics,cost-effectiveness,and ability to convert and store energy efficiently.Efficient intramolecular charge transfer among different parts of the carbon electrocatalyst and/or intermolecular charge transfer between elec-trocatalyst and electrolyte dictate the ultimate energy conversion performance.Experimental results and theoretical analyses have demonstrated that rational design of metal-free carbon nanomaterials,coupled with proper in-tramolecular charge transfer through heteroatom doping,incorporation of Stone-Wales defects,and/or intermolecular charge transfer through adsorp-tion of appropriate molecules/moieties,can promote efficient electrocatalysis.In this article,we will first provide the related theoretical principles and then present an overview on the rational design and development of C-MFECs for efficient charge transfer,followed by elucidating charge-transfer processes for different electrocatalytic reactions related to renewable energy conversion and environmental remediation technologies.Finally,the current challenges and future perspectives in this exciting field will be discussed.展开更多
基金We are also grateful for financial support from Australian Research Council(ARCDP 190103881,FL 190100126,and IH180100020)the University of New South Wales(UNSW)Materials and Manufacturing Futures Institute.
文摘CONSPECTUS:Due to the overuse of fossil fuels,various detrimental effects along with the excess CO_(2)emissions have induced global warming and sea-level rising.To tackle climate change and provide a cleaner environment for the air we breathe and water we consume,the existing energy mix needs to be changed into fossil-free,clean,renewable energy with zero emission(e.g.,fuel cells).While providing a promising and scalable strategy to the energy and environmental challenges,renewable energy processes often involve noble-metal-based catalysts(i.e.,Pt,RuO_(2)).However,the disadvantages of noblemetal-based catalysts,including their high cost and scarcity,have hampered the large-scale application of renewable energy technologies.In 2009,we discovered earth-abundant carbon materials functioning as efficient low-cost,carbon-based metal-free electrocatalysts(C-MFECs)attractive for renewable energy and environmental remediation.Since then,C-MFECs have become an emerging new research field over the world.They are demonstrated to be efficient multifunctional catalysts for various key reactions important to renewable energy and environmental technologies,including oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),oxygen evolution reaction(OER),CO_(2)reduction reaction(CO_(2)RR),and N_(2)reduction reaction(NRR),to name a few.Charge transfer/redistribution induced by heteroatom(e.g.,N)and/or defect doping was recognized as the driving force for the metal-free catalytic activities.This finding has been used as a guidance to design and develop various new and multifunctional C-MFECs for many reactions even beyond the renewable energy and environmental remediation.In this Account,we first summarize our previous work on the development and mechanistic understanding of C-MFECs for ORR,HER,and OER to promote renewable energy conversion and storage.Then,we present recent advances in C-MFECs for new important reactions for environment remediation(e.g.,CO_(2)RR,NRR),seawater splitting,and metal−CO_(2)batteries.However,different dopant locations for C-MFECs even with the same doping element and content can cause variable catalytic properties for heteroatom-doped carbon materials.Therefore,vast opportunities remain for further developing numerous innovative C-MFECs with defined structures to gain a better understanding of their structure-based properties.In this context,we finally conclude with the current challenges and future perspectives in this exciting field.
基金RP would like to thank Air Force Research Laboratory(AFRL)for providing financial support(Grant:165852.02.00.0001.00.06-C2 under prime contract FA8650-16-D-5852)LD is grateful to Australian Re-search Council(ARC,DP 190103881 and FL 190100126)for partial support.
文摘Recently,carbon-based metal-free electrocatalysts(C‐MFECs)have drawn considerable research attention because of their attractive physicochemical characteristics,cost-effectiveness,and ability to convert and store energy efficiently.Efficient intramolecular charge transfer among different parts of the carbon electrocatalyst and/or intermolecular charge transfer between elec-trocatalyst and electrolyte dictate the ultimate energy conversion performance.Experimental results and theoretical analyses have demonstrated that rational design of metal-free carbon nanomaterials,coupled with proper in-tramolecular charge transfer through heteroatom doping,incorporation of Stone-Wales defects,and/or intermolecular charge transfer through adsorp-tion of appropriate molecules/moieties,can promote efficient electrocatalysis.In this article,we will first provide the related theoretical principles and then present an overview on the rational design and development of C-MFECs for efficient charge transfer,followed by elucidating charge-transfer processes for different electrocatalytic reactions related to renewable energy conversion and environmental remediation technologies.Finally,the current challenges and future perspectives in this exciting field will be discussed.
