Although scientists have conducted long-term and extensive studies on oxygen reduction reaction(ORR)catalyzed by metal-free carbon materials,they mainly have focused on the preparation and properties of various doped ...Although scientists have conducted long-term and extensive studies on oxygen reduction reaction(ORR)catalyzed by metal-free carbon materials,they mainly have focused on the preparation and properties of various doped carbon materials.There is still a lack of systematic scientific guidance on the relationship between the surface structure regulation and activity of carbon-based catalysts.In this review,some of electrochemical and computational fundamental concepts about ORR are concisely summarized.The effects of edge defect and nonmetallic doping of carbon materials on ORR behavior and mechanism have been reviewed,and activity origin identification and intermediate conversion mechanism have been discussed.The outlooks for future researches on metal-free ORR electrocatalysis are suggested.展开更多
Heteroatom-doping of carbocatalysts has been a powerful strategy to remarkably enhance the catalytic performance.Herein,the underlying nature of N promotional effects on peroxymonosulfate(PMS)activation for phenol rem...Heteroatom-doping of carbocatalysts has been a powerful strategy to remarkably enhance the catalytic performance.Herein,the underlying nature of N promotional effects on peroxymonosulfate(PMS)activation for phenol removal is understood by combining kinetics analysis with multiple techniques.A strategy using mixed acid oxidation of carbon nanotube(CNT)followed by NH3 treatment is employed to yield a series of catalysts with different N-doping contents but similar fraction of sp^(2)-hybridized carbon and defective degree,endowing with a chance to discriminate the dominant N-containing active sites.The multi-sites kinetics analysis suggests the graphitic N-containing sites as the dominant active sites.The mechanism of the surface-bound reactive species is also discriminated as the dominant reaction mechanism.The insights reported here could provide the methodology to fundamentally understand the heteroatom-doping effects of carbocatalysis.展开更多
The carbon-based metal-free materials as catalysts(named as carbocatalysts) have been attracting tremendous attentions in electric-,solar-and thermal-driven reactions nowadays.Compared to electrocatalysis and photocat...The carbon-based metal-free materials as catalysts(named as carbocatalysts) have been attracting tremendous attentions in electric-,solar-and thermal-driven reactions nowadays.Compared to electrocatalysis and photocatalysis,the thermal-driven catalysis(thermocatalysis) including liquid phase and gas phase reactions involves wider scope and is relatively easy to realize practical large-scale applications.Over the past several years,some striking achievements on the design of new carbon-based metal-free materials with well-defined structures and heteroatom groups as well as the revelation of new reaction mechanisms and active sites in thermocatalysis have been obtained.However,comparative discussions regarding these recent achievements have been rarely highlighted.In this review,we systematically summarize and discuss six kinds of carbocatalysts and their applications in thermocatalysis.These materials include typical oxygen-attached carbon,surface modified carbon(graft with certain organic compounds),mono-doped carbon,co-doped carbon,carbon nitride and materials with carbon as dopant.Some new reaction processes as well as the related reaction mechanisms,active sites and intermediates are reviewed critically.Moreover,an outlook on the in-depth investigation of the metalfree carbocatalysis in the future is provided.展开更多
The chemodivergent ring-opening of cyclobutanols is described under the carbocatalytic assistance of graphene oxide(GO).The protocol enables the synthesis of diversely functionalized dienes or indenes(26 examples)base...The chemodivergent ring-opening of cyclobutanols is described under the carbocatalytic assistance of graphene oxide(GO).The protocol enables the synthesis of diversely functionalized dienes or indenes(26 examples)based on the amount of GO employed.Spectroscopic(XPS and ssNMR)as well as experimental investigations revealed a direct involvement of theπ-domains of GO in tuning the stability of carbocationic intermediates during the reaction.展开更多
基金support from the National Natural Science Foundation of China(nos.21872041,21373091)the Science and Technology Project of Guangzhou city(no.201704030040)。
文摘Although scientists have conducted long-term and extensive studies on oxygen reduction reaction(ORR)catalyzed by metal-free carbon materials,they mainly have focused on the preparation and properties of various doped carbon materials.There is still a lack of systematic scientific guidance on the relationship between the surface structure regulation and activity of carbon-based catalysts.In this review,some of electrochemical and computational fundamental concepts about ORR are concisely summarized.The effects of edge defect and nonmetallic doping of carbon materials on ORR behavior and mechanism have been reviewed,and activity origin identification and intermediate conversion mechanism have been discussed.The outlooks for future researches on metal-free ORR electrocatalysis are suggested.
基金supported by the Natural Science Foundation of China(21922803 and 21776077)the Shanghai Natural Science Foundation(17ZR1407300 and 17ZR1407500)+3 种基金the China Postdoctoral Science Foundation(BX20190116)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,the Shanghai Rising-Star Program(17QA1401200)the State Key Laboratory of Organic-Inorganic Composites(oic-201801007)the Open Project of State Key Laboratory of Chemical Engineering(SKLChe-15C03 and SKL-ChE-16C05).
文摘Heteroatom-doping of carbocatalysts has been a powerful strategy to remarkably enhance the catalytic performance.Herein,the underlying nature of N promotional effects on peroxymonosulfate(PMS)activation for phenol removal is understood by combining kinetics analysis with multiple techniques.A strategy using mixed acid oxidation of carbon nanotube(CNT)followed by NH3 treatment is employed to yield a series of catalysts with different N-doping contents but similar fraction of sp^(2)-hybridized carbon and defective degree,endowing with a chance to discriminate the dominant N-containing active sites.The multi-sites kinetics analysis suggests the graphitic N-containing sites as the dominant active sites.The mechanism of the surface-bound reactive species is also discriminated as the dominant reaction mechanism.The insights reported here could provide the methodology to fundamentally understand the heteroatom-doping effects of carbocatalysis.
基金supported by the Award Program for Fujian Minjiang Scholar Professorship,the National Natural Science Foundation of China(21571035)Chemical Engineering&Technology of Zhejiang Province First-Class Discipline(Taizhou University),Zhejiang Provincial Natural Science Foundation of China(LQ20B060001)Taizhou science and technology planning project(1902gy20)。
文摘The carbon-based metal-free materials as catalysts(named as carbocatalysts) have been attracting tremendous attentions in electric-,solar-and thermal-driven reactions nowadays.Compared to electrocatalysis and photocatalysis,the thermal-driven catalysis(thermocatalysis) including liquid phase and gas phase reactions involves wider scope and is relatively easy to realize practical large-scale applications.Over the past several years,some striking achievements on the design of new carbon-based metal-free materials with well-defined structures and heteroatom groups as well as the revelation of new reaction mechanisms and active sites in thermocatalysis have been obtained.However,comparative discussions regarding these recent achievements have been rarely highlighted.In this review,we systematically summarize and discuss six kinds of carbocatalysts and their applications in thermocatalysis.These materials include typical oxygen-attached carbon,surface modified carbon(graft with certain organic compounds),mono-doped carbon,co-doped carbon,carbon nitride and materials with carbon as dopant.Some new reaction processes as well as the related reaction mechanisms,active sites and intermediates are reviewed critically.Moreover,an outlook on the in-depth investigation of the metalfree carbocatalysis in the future is provided.
基金financial support and to the Italian Ministry of Education,University and Research(MIUR)PRIN-2017 project 2017W8KNZWThe research leading to these results has received funding from the European Union's Horizon 2020 research and innovation programme under Graphene Core3881603-Graphene+1 种基金Flagship.F.B.and E.R.acknowledge the MIUR,and European Social Fund(ESF)for the PON R&l 2014-2020 program,action IV.4"Doctorates and research contracts on Innovation topics"This work benefited from access(ITAO17)to CERM/CIRMMP,Italy centre of Instruct-ERIC,a Landmak ESFRI project,for the ssNMR measurements and support.
文摘The chemodivergent ring-opening of cyclobutanols is described under the carbocatalytic assistance of graphene oxide(GO).The protocol enables the synthesis of diversely functionalized dienes or indenes(26 examples)based on the amount of GO employed.Spectroscopic(XPS and ssNMR)as well as experimental investigations revealed a direct involvement of theπ-domains of GO in tuning the stability of carbocationic intermediates during the reaction.