In recent decades,the environmental protection and long-term sustainability have become the focus of attention due to the increasing pollution generated by the intense industrialization.To overcome these issues,enviro...In recent decades,the environmental protection and long-term sustainability have become the focus of attention due to the increasing pollution generated by the intense industrialization.To overcome these issues,environmental catalysis has increasingly been used to solve the negative impact of pollutants emission on the global environment and human health.Supported platinum-metal-group(PGM)materials are commonly utilized as the state-of-the-art catalysts to eliminate gaseous pollutants but large quantities of PGMs are required.By comparison,single-atom site catalysts(SACs)have attracted much attention in catalysis owing to their 100%atom efficiency and unique catalytic performances towards various reactions.Over the past decade,we have witnessed burgeoning interests of SACs in heterogeneous catalysis.However,to the best of our knowledge,the systematic summary and analysis of SACs in catalytic elimination of environmental pollutants has not yet been reported.In this paper,we summarize and discuss the environmental catalysis applications of SACs.Particular focus was paid to automotive and stationary emission control,including model reaction(CO oxidation,NO reduction and hydrocarbon oxidation),overall reaction(three-way catalytic and diesel oxidation reaction),elimination of volatile organic compounds(formaldehyde,benzene,and toluene),and removal/decomposition of other pollutants(Hg0 and SO3).Perspectives related to further challenges,directions and design strategies of single-atom site catalysts in environmental catalysis were also provided.展开更多
Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to ...Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.展开更多
The oxidation of hydrocarbons to produce high value-added compounds(ketones or alcohols)using oxygen in air as the only oxidant is an efficient synthetic strategy from both environmental and economic views.Herein,we s...The oxidation of hydrocarbons to produce high value-added compounds(ketones or alcohols)using oxygen in air as the only oxidant is an efficient synthetic strategy from both environmental and economic views.Herein,we successfully synthesized cobalt single atom site catalysts(Co SACs)with high metal loading of 23.58 wt.%supported on carbon nitride(CN),which showed excellent catalytic properties for oxidation of ethylbenzene in air.Moreover,Co SACs show a much higher turn-over frequency(19.6 h^(−1))than other reported non-noble catalysts under the same condition.Comparatively,the as-obtained nanosized or homogenous Co catalysts are inert to this reaction.Co SACs also exhibit high selectivity(97%)and stability(unchanged after five runs)in this reaction.DFT calculations reveal that Co SACs show a low energy barrier in the first elementary step and a high resistance to water,which result in the robust catalytic performance for this reaction.展开更多
With the ever-pressing issues of global energy demand and environmental pollution,molecular hydrogen has been receiving increasing attention as a clean alternative energy carrier.For hydrogen production,the design and...With the ever-pressing issues of global energy demand and environmental pollution,molecular hydrogen has been receiving increasing attention as a clean alternative energy carrier.For hydrogen production,the design and development of high-performance catalysts remains rather challenging.As the compositions and structures of catalyst interfaces have paramount influences on the catalytic performances,the central topic here has always been to design and engineer the interface structures via rational routes so as to boost the activities and stabilities of electrocatalysts on hydrogen evolution reaction(HER).Here in this review,we focus on the design and preparation of multi-scale catalysts specifically catering to HER applications.We start from the design and structure-activity relationship of catalytic nanostructures,summarize the research progresses related to HER nanocatalysts,and interpret their high activities from the atomistic perspective;then,we review the studies regarding the design,preparation,HER applications and structure-activity relationship of single-atom site catalysts(SASCs),and thereupon discuss the future directions in designing HER-oriented SASCs.At the end of this review,we present an outlook on the development trends and faced challenges of catalysts for electrochemical HER.展开更多
Background:Trocar-site hernia(TSH)is a serious complication after laparoscopic procedures.Although it is a rare entity,it have life-threatening consequences.This study aimed to retrospectively analyze the potential as...Background:Trocar-site hernia(TSH)is a serious complication after laparoscopic procedures.Although it is a rare entity,it have life-threatening consequences.This study aimed to retrospectively analyze the potential associated factors for TSH following gynecologic laparoscopy and summarize prevention strategies based on our experience.Methods:We searched for gynecological laparoscopic surgeries in the medical records system of Peking Union Medical College Hospital(PUMCH)from August 1998 to July 2018 and further sifted through the results for cases involving TSH.All included patients were divided into different groups according to patient characteristics,and the rate of TSH was compared among groups.Moreover,the detailed information of all patients with TSH was recorded and analyzed.Statistical analyses were performed with GraphPad Prism 6.Results:The approximate total rate of post-operative TSH among gynecologic laparoscopy procedures performed at PUMCH in the last 20 years was 0.016%(9/55,244).The rate of TSH was significant higher in elder patients(>60 years old;3/2686,0.112%)than in younger patients(<60 years old,6/52,558;0.011%,P=0.008).Moreover,the approximate rate of TSH was significantly higher after single-incision laparoscopic surgery(SILS,2/534,0.357%)than conventional laparoscopic surgery(7/54,710,0.013%,P=0.003).The average age of patients with TSH was 53.4 years(range,35.0-79.0 years).Two of the nine patients had late-onset TSH following SILS;the other seven had early-onset TSH following conventional laparoscopy.Five TSH cases occurred at right lateral port sites,and the remaining three occurred at the umbilical port site.All patients underwent repair surgery,and one required small bowel resection.Conclusion:Older age and SILS are potential associated factors for TSH development,while reducing excessive manipulation and improving suturing skills,especially at the umbilical trocar site following SILS and the right lateral trocar site,can avoid herniation.展开更多
目的探讨经脐单一部位腹腔镜技术在急腹症诊疗中的安全性和可行性。方法回顾性分析2011年1～9月100例以急腹症行经脐单一部位腹腔镜探查的临床资料。经脐纵行切口20 mm,置入硅胶切口保护套(欣皮护)后送入腹腔镜trocar并开始注气,5 mm治...目的探讨经脐单一部位腹腔镜技术在急腹症诊疗中的安全性和可行性。方法回顾性分析2011年1～9月100例以急腹症行经脐单一部位腹腔镜探查的临床资料。经脐纵行切口20 mm,置入硅胶切口保护套(欣皮护)后送入腹腔镜trocar并开始注气,5 mm治疗镜探查腹腔;根据不同病变,采用相应的治疗措施。结果 100例中,85例为急性阑尾炎,其中76例经脐提出阑尾切除,因阑尾坏疽,局部炎症重,或腹膜后位阑尾,4例行经脐单一部位腹腔内阑尾切除;5例从耻骨上另外置入5 mm trocar完成腹腔内阑尾切除。8例胃穿孔,其中6例经脐单一部位行修补术,2例从右上腹置入5 mm trocar完成修补术。1例出血性小肠炎,经脐提出行回肠切除、空肠造瘘术。2例女性盆腔感染,经脐单一部位行盆腹腔灌洗术。1例卵巢囊肿蒂扭转,经脐单一部位行卵巢囊肿切除术。1例下腹局部肠粘连,经脐单一部位行粘连松解术。2例术中发现腹腔内有乳糜样积液,其中1例为自发性乳糜性腹膜炎,经钛夹夹闭渗漏淋巴管和腹腔冲洗后治愈,另1例为空肠系膜淋巴管瘤,中转开腹切除。术后脐部渗液3例,肠麻痹2例。术后随访6～9个月,脐部切口愈合好,隐蔽,无脐切口疝。结论应用小的硅胶切口保护套经脐单一部位腹腔镜探查安全可行,美容效果较好。展开更多
基金This work was supported by the China Postdoctoral Science Foundation(No.2020M670355)the National Key R&D Program of China(No.2018YFA0702003)+2 种基金the National Natural Science Foundation of China(Nos.21890383,21671117,and 21871159)the Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)Beijing Municipal Science&Technology Commission(No.Z191100007219003).
文摘In recent decades,the environmental protection and long-term sustainability have become the focus of attention due to the increasing pollution generated by the intense industrialization.To overcome these issues,environmental catalysis has increasingly been used to solve the negative impact of pollutants emission on the global environment and human health.Supported platinum-metal-group(PGM)materials are commonly utilized as the state-of-the-art catalysts to eliminate gaseous pollutants but large quantities of PGMs are required.By comparison,single-atom site catalysts(SACs)have attracted much attention in catalysis owing to their 100%atom efficiency and unique catalytic performances towards various reactions.Over the past decade,we have witnessed burgeoning interests of SACs in heterogeneous catalysis.However,to the best of our knowledge,the systematic summary and analysis of SACs in catalytic elimination of environmental pollutants has not yet been reported.In this paper,we summarize and discuss the environmental catalysis applications of SACs.Particular focus was paid to automotive and stationary emission control,including model reaction(CO oxidation,NO reduction and hydrocarbon oxidation),overall reaction(three-way catalytic and diesel oxidation reaction),elimination of volatile organic compounds(formaldehyde,benzene,and toluene),and removal/decomposition of other pollutants(Hg0 and SO3).Perspectives related to further challenges,directions and design strategies of single-atom site catalysts in environmental catalysis were also provided.
基金supported by the National Key R&D Program of China(Nos.2018YFA0702003 and 2016YFA0202801)the National Natural Science Foundation of China(Nos.21890383,21671117,21871159,and 21901135)+2 种基金the National Postdoctoral Program for Innovative Talents,the Shuimu Tsinghua Scholar,Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)Beijing Municipal Science&Technology Commission(No.Z191100007219003)We thank the BL14W1 station in Shanghai Synchrotron Radiation Facility(SSRF)and 1W1B station for XAFS measurement in Beijing Synchrotron Radiation Facility(BSRF).
文摘Single-atom site(SA)catalysts on N-doped carbon(CN)materials exhibit prominent performance for their active sites being M-Nx.Due to the commonly random doping behaviors of N species in these CN,it is a tough issue to finely regulate their doping types and clarify their effect on the catalytic property of such catalysts.Herein,we report that the N-doping type in CN can be dominated as pyrrolic-N and pyridinic-N respectively through compounding with different metal oxides.It is found that the proportion of distinct doped N species in CN depends on the acidity and basicity of compounded metal oxide host.Owing to the coordination by pyrrolic-N,the SA Cu catalyst displays an enhanced activity(two-fold)for transfer hydrogenation of quinoline to access the valuable molecule tetrahydroquinoline with a good selectivity(99%)under mild conditions.The higher electron density of SA Cu species induced by the predominate pyrrolic-N coordination benefits the hydrogen transfer process and reduces the energy barrier of the hydrogenation pathway,which accounts for the improved catalytic effeciency.
基金This work was supported by the National Key R&D Program of China(Nos.2018YFA0702003 and 2016YFA0202801)the National Natural Science Foundation of China(Nos.21890383,21671117,21871159,and 21901135)+2 种基金Science and Technology Key Project of Guangdong Province of China(No.2020B010188002)Beijing Municipal Science&Technology Commission(No.Z191100007219003)China Postdoctoral Science Foundation(No.2018M640114).
文摘The oxidation of hydrocarbons to produce high value-added compounds(ketones or alcohols)using oxygen in air as the only oxidant is an efficient synthetic strategy from both environmental and economic views.Herein,we successfully synthesized cobalt single atom site catalysts(Co SACs)with high metal loading of 23.58 wt.%supported on carbon nitride(CN),which showed excellent catalytic properties for oxidation of ethylbenzene in air.Moreover,Co SACs show a much higher turn-over frequency(19.6 h^(−1))than other reported non-noble catalysts under the same condition.Comparatively,the as-obtained nanosized or homogenous Co catalysts are inert to this reaction.Co SACs also exhibit high selectivity(97%)and stability(unchanged after five runs)in this reaction.DFT calculations reveal that Co SACs show a low energy barrier in the first elementary step and a high resistance to water,which result in the robust catalytic performance for this reaction.
基金Acknowledgements This work was supported by the National Key R&D Program of China(2016YFA0202801,2017YFA0700101 and 2018YFA0702003)the National Natural Science Foundation of China(21925202,21872076 and 21890383)+4 种基金Beijing Natural Science Foundation(JQ18007)the Fundamental Research Funds for the Central Universities(19CX02008A)the Petro China Innovation Foundation(2019D-5007-0401)Taishan Scholars Program of Shandong Province(tsqn201909065)Tsinghua University Initiative Scientific Research Program.
文摘With the ever-pressing issues of global energy demand and environmental pollution,molecular hydrogen has been receiving increasing attention as a clean alternative energy carrier.For hydrogen production,the design and development of high-performance catalysts remains rather challenging.As the compositions and structures of catalyst interfaces have paramount influences on the catalytic performances,the central topic here has always been to design and engineer the interface structures via rational routes so as to boost the activities and stabilities of electrocatalysts on hydrogen evolution reaction(HER).Here in this review,we focus on the design and preparation of multi-scale catalysts specifically catering to HER applications.We start from the design and structure-activity relationship of catalytic nanostructures,summarize the research progresses related to HER nanocatalysts,and interpret their high activities from the atomistic perspective;then,we review the studies regarding the design,preparation,HER applications and structure-activity relationship of single-atom site catalysts(SASCs),and thereupon discuss the future directions in designing HER-oriented SASCs.At the end of this review,we present an outlook on the development trends and faced challenges of catalysts for electrochemical HER.
文摘Background:Trocar-site hernia(TSH)is a serious complication after laparoscopic procedures.Although it is a rare entity,it have life-threatening consequences.This study aimed to retrospectively analyze the potential associated factors for TSH following gynecologic laparoscopy and summarize prevention strategies based on our experience.Methods:We searched for gynecological laparoscopic surgeries in the medical records system of Peking Union Medical College Hospital(PUMCH)from August 1998 to July 2018 and further sifted through the results for cases involving TSH.All included patients were divided into different groups according to patient characteristics,and the rate of TSH was compared among groups.Moreover,the detailed information of all patients with TSH was recorded and analyzed.Statistical analyses were performed with GraphPad Prism 6.Results:The approximate total rate of post-operative TSH among gynecologic laparoscopy procedures performed at PUMCH in the last 20 years was 0.016%(9/55,244).The rate of TSH was significant higher in elder patients(>60 years old;3/2686,0.112%)than in younger patients(<60 years old,6/52,558;0.011%,P=0.008).Moreover,the approximate rate of TSH was significantly higher after single-incision laparoscopic surgery(SILS,2/534,0.357%)than conventional laparoscopic surgery(7/54,710,0.013%,P=0.003).The average age of patients with TSH was 53.4 years(range,35.0-79.0 years).Two of the nine patients had late-onset TSH following SILS;the other seven had early-onset TSH following conventional laparoscopy.Five TSH cases occurred at right lateral port sites,and the remaining three occurred at the umbilical port site.All patients underwent repair surgery,and one required small bowel resection.Conclusion:Older age and SILS are potential associated factors for TSH development,while reducing excessive manipulation and improving suturing skills,especially at the umbilical trocar site following SILS and the right lateral trocar site,can avoid herniation.
文摘目的探讨经脐单一部位腹腔镜技术在急腹症诊疗中的安全性和可行性。方法回顾性分析2011年1～9月100例以急腹症行经脐单一部位腹腔镜探查的临床资料。经脐纵行切口20 mm,置入硅胶切口保护套(欣皮护)后送入腹腔镜trocar并开始注气,5 mm治疗镜探查腹腔;根据不同病变,采用相应的治疗措施。结果 100例中,85例为急性阑尾炎,其中76例经脐提出阑尾切除,因阑尾坏疽,局部炎症重,或腹膜后位阑尾,4例行经脐单一部位腹腔内阑尾切除;5例从耻骨上另外置入5 mm trocar完成腹腔内阑尾切除。8例胃穿孔,其中6例经脐单一部位行修补术,2例从右上腹置入5 mm trocar完成修补术。1例出血性小肠炎,经脐提出行回肠切除、空肠造瘘术。2例女性盆腔感染,经脐单一部位行盆腹腔灌洗术。1例卵巢囊肿蒂扭转,经脐单一部位行卵巢囊肿切除术。1例下腹局部肠粘连,经脐单一部位行粘连松解术。2例术中发现腹腔内有乳糜样积液,其中1例为自发性乳糜性腹膜炎,经钛夹夹闭渗漏淋巴管和腹腔冲洗后治愈,另1例为空肠系膜淋巴管瘤,中转开腹切除。术后脐部渗液3例,肠麻痹2例。术后随访6～9个月,脐部切口愈合好,隐蔽,无脐切口疝。结论应用小的硅胶切口保护套经脐单一部位腹腔镜探查安全可行,美容效果较好。
