Zeolite-loaded noble metal catalysts have demonstrated excellent performance in addressing cold-start automotive exhaust NOx emissions and catalytic oxidation of VOCs applications.Pd and Pt are the most commonly used ...Zeolite-loaded noble metal catalysts have demonstrated excellent performance in addressing cold-start automotive exhaust NOx emissions and catalytic oxidation of VOCs applications.Pd and Pt are the most commonly used active metals in PNA and VOC catalysts,respectively.However,despite the same metal/zeolite composition,the efficient active sites for PNA and VOC catalysts have been viewed as mainly Pd2t and Pt0,respectively,both of which are different from each other.As a result,various methods need to be applied to dope Pd and Pt in zeolitic support respectively for different usages.No matter which type of metal species is needed,the common requirement for both PNA and VOC catalysts is that the metal species should be highly dispersed in zeolite support and stay stable.The purpose of this paper is to review the progress of synthetic means of zeolite-coated noble metals(Pd,Pt,etc.)as effective PNA or VOC catalysts.To give a better understanding of the relationship between efficient metal species and the introduced methods,the species that contributed to the NOx adsorption(PNA)and VOCs deep catalytic oxidation were first summarized and compared.Then,based on the above discussion,the detailed construction strategies for different active sites in PNA and VOC catalysts,respectively,were elaborated in terms of synthetic routes,precursor selection,and zeolite carrier requirements.It is hoped that this will contribute to a better understanding of noble metal adsorption/catalysis in zeolites and provide promising strategies for the design of adsorption/catalysts with high activity,selectivity and stability.展开更多
By integrating literature reviews, site observa- tion, field monitoring, theoretical analysis, summarization, etc., a construction strategy was proposed and verified for tunneling with big deformation in this paper. T...By integrating literature reviews, site observa- tion, field monitoring, theoretical analysis, summarization, etc., a construction strategy was proposed and verified for tunneling with big deformation in this paper. The tunnel was in phyllite, shotcrete cracks and steel arch distortion were observed, and a big deformation with a maximum of 2.0 m was monitored during the initial stage of the construction. Through carefully examining the site observation and laboratory test results, a construction principle was established for the tunneling on the basic concept of maintaining the rock strength/stiffness and keeping the rock dry, by providing confinement pressure to the rock, reducing the rock exposure time, keeping water out of the tunnel, etc. To achieve the construction principle, a set of specific construction measures with 11 items was further proposed and applied to the construction. To check the effectiveness of the construction measures, field monitoring was carried out, which showed that the rock deformation was well controlled and the tunnel became stable. An allowable deformation was then determined using the Fenner formulae and the monitored data in order to guide further construction, which received a good result. From this study, it can be concluded that providing quick strong initial support and reserving core soil at the working faceare extremely important to control the rock deformation and keep the tunnel stable.展开更多
Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the H...Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the Haber-Bosch process and electrochemical nitrogen reduction reaction.Therefore,it represents a promising approach to safeguard the ecological environment by enabling the cycling of nitrogen species.This review begins by discussing the theoretical insights of the NO_(3)RR.It then summarizes recent advances in catalyst design and construction strategies,including alloying,structure engineering,surface engineering,and heterostructure engineering.Finally,the challenges and prospects in this field are presented.This review aims to guide for enhancing the efficiency of electrocatalysts in the NO_(3)RR,and offers insights for converting NO_(3)-to NH_(3).展开更多
With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,off...With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.展开更多
Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost ...Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost catalysts for OER process is essential as the conventional catalysts still rely on precious metals.Transition metal-based compounds have been widely investigated as active OER catalysts,and renewed interest in the high valence metals engineered compounds has been achieved for superior catalytic activity and stability.However,an in-depth understanding of the construction strategies and induced effects for the high valence metals engineered catalysts is still lacking and desired.In this review,we have summarized the construction strategies of high valence metals as dopants or formed heterostructures with the iron/cobalt/nickel(Fe/Co/Ni)-based catalysts.Then the induced effects on Fe/Co/Ni-based catalysts by incorporating high valence metals,e.g.,accelerating the surface reconstruction,forming amorphous structure,generating vacancies/defects,and acting as stabilizers,are highlighted.The impacts of high valence metals on OER performance are elucidated based on different elements,including molybdenum(Mo),tungsten(W),cerium(Ce),vanadium(V),chromium(Cr),manganese(Mn),niobium(Nb),zirconium(Zr).The correlations of construction strategies,induced effects,catalytic activity and OER reaction pathways are elaborated.Finally,the remaining challenges for further enhancements of OER performance induced by high valence metals are presented.展开更多
基金supported by Zhongtian Iron and Steel-University of Science and Technology Beijing Youth Science and Technology Innovation Fund(No.FZTNTC2024050005)National Engineering Laboratory for Mobile Source Emission Control Technology,China(No.NELMS2020A07)The Fundamental Research Funds for the Central Universities,China(No.FRF-AT-20-12)。
文摘Zeolite-loaded noble metal catalysts have demonstrated excellent performance in addressing cold-start automotive exhaust NOx emissions and catalytic oxidation of VOCs applications.Pd and Pt are the most commonly used active metals in PNA and VOC catalysts,respectively.However,despite the same metal/zeolite composition,the efficient active sites for PNA and VOC catalysts have been viewed as mainly Pd2t and Pt0,respectively,both of which are different from each other.As a result,various methods need to be applied to dope Pd and Pt in zeolitic support respectively for different usages.No matter which type of metal species is needed,the common requirement for both PNA and VOC catalysts is that the metal species should be highly dispersed in zeolite support and stay stable.The purpose of this paper is to review the progress of synthetic means of zeolite-coated noble metals(Pd,Pt,etc.)as effective PNA or VOC catalysts.To give a better understanding of the relationship between efficient metal species and the introduced methods,the species that contributed to the NOx adsorption(PNA)and VOCs deep catalytic oxidation were first summarized and compared.Then,based on the above discussion,the detailed construction strategies for different active sites in PNA and VOC catalysts,respectively,were elaborated in terms of synthetic routes,precursor selection,and zeolite carrier requirements.It is hoped that this will contribute to a better understanding of noble metal adsorption/catalysis in zeolites and provide promising strategies for the design of adsorption/catalysts with high activity,selectivity and stability.
文摘By integrating literature reviews, site observa- tion, field monitoring, theoretical analysis, summarization, etc., a construction strategy was proposed and verified for tunneling with big deformation in this paper. The tunnel was in phyllite, shotcrete cracks and steel arch distortion were observed, and a big deformation with a maximum of 2.0 m was monitored during the initial stage of the construction. Through carefully examining the site observation and laboratory test results, a construction principle was established for the tunneling on the basic concept of maintaining the rock strength/stiffness and keeping the rock dry, by providing confinement pressure to the rock, reducing the rock exposure time, keeping water out of the tunnel, etc. To achieve the construction principle, a set of specific construction measures with 11 items was further proposed and applied to the construction. To check the effectiveness of the construction measures, field monitoring was carried out, which showed that the rock deformation was well controlled and the tunnel became stable. An allowable deformation was then determined using the Fenner formulae and the monitored data in order to guide further construction, which received a good result. From this study, it can be concluded that providing quick strong initial support and reserving core soil at the working faceare extremely important to control the rock deformation and keep the tunnel stable.
基金supported by the National Natural Science Foundation of China(22202151)Fundamental Research Program of Shanxi Province(202203021212243)。
文摘Ammonia plays an essential role in human production and life as a raw material for chemical fertilizers.The nitrate electroreduction to ammonia reaction(NO_(3)RR)has garnered attention due to its advantages over the Haber-Bosch process and electrochemical nitrogen reduction reaction.Therefore,it represents a promising approach to safeguard the ecological environment by enabling the cycling of nitrogen species.This review begins by discussing the theoretical insights of the NO_(3)RR.It then summarizes recent advances in catalyst design and construction strategies,including alloying,structure engineering,surface engineering,and heterostructure engineering.Finally,the challenges and prospects in this field are presented.This review aims to guide for enhancing the efficiency of electrocatalysts in the NO_(3)RR,and offers insights for converting NO_(3)-to NH_(3).
基金financially supported by National Key R&D Program of China(2021YFB3500702)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04).
文摘With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.
基金supported by the Australian Research Council(ARC)through the Discovery Project(DP180102297)the Future Fellow Project(FT180100705)+2 种基金the support from the Open Project of State Key Laboratory of Advanced Special Steelthe Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS 2021-**)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270200,20511107700)。
文摘Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost catalysts for OER process is essential as the conventional catalysts still rely on precious metals.Transition metal-based compounds have been widely investigated as active OER catalysts,and renewed interest in the high valence metals engineered compounds has been achieved for superior catalytic activity and stability.However,an in-depth understanding of the construction strategies and induced effects for the high valence metals engineered catalysts is still lacking and desired.In this review,we have summarized the construction strategies of high valence metals as dopants or formed heterostructures with the iron/cobalt/nickel(Fe/Co/Ni)-based catalysts.Then the induced effects on Fe/Co/Ni-based catalysts by incorporating high valence metals,e.g.,accelerating the surface reconstruction,forming amorphous structure,generating vacancies/defects,and acting as stabilizers,are highlighted.The impacts of high valence metals on OER performance are elucidated based on different elements,including molybdenum(Mo),tungsten(W),cerium(Ce),vanadium(V),chromium(Cr),manganese(Mn),niobium(Nb),zirconium(Zr).The correlations of construction strategies,induced effects,catalytic activity and OER reaction pathways are elaborated.Finally,the remaining challenges for further enhancements of OER performance induced by high valence metals are presented.
