Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum s...Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum solvation model to predict the reaction energetics of NO3RR on pure copper surface in alkaline media.The potential-dependent mechanism on the most prevailing Cu(111)and the minor(100)and(110)facets were established,in consideration of NO_(2)_(−),NO,NH_(3),NH_(2)OH,N_(2),and N_(2)O as the main products.The computational results show that the major Cu(111)is the ideal surface to produce ammonia with the highest onset potential at 0.06 V(until−0.37 V)and the highest optimal potential at−0.31 V for ammonia production without kinetic obstacles in activation energies at critical steps.For other minor facets,the secondary Cu(100)shows activity to ammonia from−0.03 to−0.54 V with the ideal potential at−0.50 V,which requires larger overpotential to overcome kinetic activation energy barriers.The least Cu(110)possesses the longest potential range for ammonia yield from−0.27 to−1.12 V due to the higher adsorption coverage of nitrate,but also with higher tendency to generate di-nitrogen species.Experimental evaluations on commercial Cu/C electrocatalyst validated the accuracy of our proposed mechanism.The most influential(111)surface with highest percentage in electrocatalyst determined the trend of ammonia production.In specific,the onset potential of ammonia production at 0.1 V and emergence of yield rate peak at−0.3 V in experiments precisely located in the predicted potentials on Cu(111).Four critical factors for the high ammonia yield and selectivity on Cu surface via NO3RR are summarized,including high NO3RR activity towards ammonia on the dominant Cu(111)facet,more possibilities to produce ammonia along different pathways on each facet,excellent ability for HER inhibition and suitable surface size to suppress di-nitrogen species formation at high nitrate coverage.Overall,our work provides comprehensive potential-dependent insights into the reaction details of NO3RR to ammonia,which can serve as references for the future development of NO3RR electrocatalysts,achieving higher activity and selectivity by maximizing these characteristics of copper-based materials.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
Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ammonia.Herein,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simpl...Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ammonia.Herein,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simple vapor-phase hydrothermal method.The resultant catalysts were evaluated for electrocatalytic nitrate reduction to ammonia(NH_(3))in three-type electrochemical reactors.In detail,the regulation mechanism of the heterogeneous Cu_(3)P-Ni_(2)P/CP-x for NO_(3)RR performance was systematically studied through the H-type cell,rotating disk electrode setup,and membrane-electrode-assemblies(MEA)electrolyzer.As a result,the Cu_(3)P-Ni_(2)P/CP-0.5 displays the practicability in an MEA system with an anion exchange membrane,affording the largest ammonia yield rate(RNH_(3))of 1.9 mmol·h^(−1)·cm^(−2),exceeding most of the electrocatalytic nitrate reduction electrocatalysts reported to date.The theoretical calculations and in-situ spectroscopy characterizations uncover that the formed heterointerface in Cu_(3)P-Ni_(2)P/CP is beneficial for promoting nitrate adsorption,activation,and conversion to ammonia through the successive hydrodeoxygenation pathway.展开更多
Atomic transition metal–nitrogen–carbon electrocatalysts exhibit outstanding activity in various electrocatalytic reactions.The challenge lies in predicting the structure of the active center,which may undergo chang...Atomic transition metal–nitrogen–carbon electrocatalysts exhibit outstanding activity in various electrocatalytic reactions.The challenge lies in predicting the structure of the active center,which may undergo changes under applied potential and interact with reactants or intermediates.Advanced characterization techniques,particularly in-situ X-ray absorption spectroscopy(XAS),provide crucial insights into the structural evolution of the metal active center during the reaction.In this study,nitrate reduction to ammonia(NO_(3)RR)was selected as a model reaction,and we introduced in-situ XAS to reveal the structural evolution during the catalytic process.A novel single atom catalyst of iron loaded on three-dimensional nitrogen–carbon nanonetwork(designated as Fe SAC/NC)was successfully synthesized.We unraveled the structural transformations occurring as pyrrole-N_(4)-Fe transitions to pyrrole-N_(3)-Fe throughout the NO_(3)RR process.Notably,the Fe SAC/NC catalyst exhibited excellent catalytic activity,achieving a Faradaic efficiency of 98.2% and an ammonia generation rate of 22,515μg·h^(−1)·mgcat−1 at−0.8 V versus reversible hydrogen electrode.Theoretical calculations combined with in-situ spectroscopic characterization showed that pyrrole-N_(3)-Fe reduced the energy barrier from *NO to*NHO and improved the selectivity of ammonia.This provides a robust reference for the design of efficient nitrate-to-ammonia synthesis catalysts.展开更多
Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)c...Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)composed hybrid catalyst(CoCuO_(x)@CuO_(x)/copper foam(CF)),characteristic of distinctive shell-core nanowires grown on CF substrate with CuO_(x)core and CoCuO_(x)shell.The built-in electric field formed at the interface of the CoO/Cu_(2)O heterostructure promotes NO3−adsorption by modulating the charge distribution at the interface,which greatly improves the ammonia yield rate and Faradaic efficiency.At−0.2 V vs.reversible hydrogen electrode(RHE),CoCuO_(x)@CuO_(x)/CF achieves not only an excellent ammonia yield rate of up to 519.1μg·h^(−1)·cm^(−2)and Faradaic efficiency of 99.83%at 1 mM NO3−concentration,but also excellent mechanical stabilities.This study provides a novel pathway to design electrocatalyst for the removal of nitrate from dilute nitric acid solutions(≤2 mM).展开更多
The effect of the amount of precipitant ammonia on the Cu0/Cu＋ratio of Cu/Si O2 prepared by the deposition–precipitation method is investigated. Species at different preparation stages, resulted from the amount of a...The effect of the amount of precipitant ammonia on the Cu0/Cu＋ratio of Cu/Si O2 prepared by the deposition–precipitation method is investigated. Species at different preparation stages, resulted from the amount of ammonia used, are identified by the XRD and FTIR techniques. Chrysocolla together with either copper nitrate hydroxide or copper hydroxide coexist in the uncalcined catalysts. Upon calcination, the latter two species are converted to Cu O particles while chrysocolla remains. Following reduction, Cu O is transformed to metallic Cu and chrysocolla is converted to Cu2 O. The value of Cu0/Cu＋ratio can be evaluated using the peak areas in their TPR profiles. Hydrogenation of dimethyl oxalate（DMO） to ethylene glycol（EG） shows that the selectivity of EG depends on the Cu0/Cu＋ratio. Catalyst prepared with the addition of ammonia solution at n（NH3）/n（Cu2＋） = 0.9 for precipitation–deposition gains a more suitable Cu0/Cu＋ratio upon reduction and thus has a higher selectivity for EG.展开更多
基金supported by is supported by the Shanghai Municipal Science and Technology Major Projectthe support from Shanghai Super Postdoctoral Incentive Program
文摘Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum solvation model to predict the reaction energetics of NO3RR on pure copper surface in alkaline media.The potential-dependent mechanism on the most prevailing Cu(111)and the minor(100)and(110)facets were established,in consideration of NO_(2)_(−),NO,NH_(3),NH_(2)OH,N_(2),and N_(2)O as the main products.The computational results show that the major Cu(111)is the ideal surface to produce ammonia with the highest onset potential at 0.06 V(until−0.37 V)and the highest optimal potential at−0.31 V for ammonia production without kinetic obstacles in activation energies at critical steps.For other minor facets,the secondary Cu(100)shows activity to ammonia from−0.03 to−0.54 V with the ideal potential at−0.50 V,which requires larger overpotential to overcome kinetic activation energy barriers.The least Cu(110)possesses the longest potential range for ammonia yield from−0.27 to−1.12 V due to the higher adsorption coverage of nitrate,but also with higher tendency to generate di-nitrogen species.Experimental evaluations on commercial Cu/C electrocatalyst validated the accuracy of our proposed mechanism.The most influential(111)surface with highest percentage in electrocatalyst determined the trend of ammonia production.In specific,the onset potential of ammonia production at 0.1 V and emergence of yield rate peak at−0.3 V in experiments precisely located in the predicted potentials on Cu(111).Four critical factors for the high ammonia yield and selectivity on Cu surface via NO3RR are summarized,including high NO3RR activity towards ammonia on the dominant Cu(111)facet,more possibilities to produce ammonia along different pathways on each facet,excellent ability for HER inhibition and suitable surface size to suppress di-nitrogen species formation at high nitrate coverage.Overall,our work provides comprehensive potential-dependent insights into the reaction details of NO3RR to ammonia,which can serve as references for the future development of NO3RR electrocatalysts,achieving higher activity and selectivity by maximizing these characteristics of copper-based materials.
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the postdoctoral researcher funding project of Anhui Province(No.2022B585)the HFIPS Director’s Fund(No.YZJJ2023QN29)+1 种基金the National Natural Science Foundation of China(No.52172106)the Special Research Assistant Program,Chinese Academy of Sciences.
文摘Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ammonia.Herein,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simple vapor-phase hydrothermal method.The resultant catalysts were evaluated for electrocatalytic nitrate reduction to ammonia(NH_(3))in three-type electrochemical reactors.In detail,the regulation mechanism of the heterogeneous Cu_(3)P-Ni_(2)P/CP-x for NO_(3)RR performance was systematically studied through the H-type cell,rotating disk electrode setup,and membrane-electrode-assemblies(MEA)electrolyzer.As a result,the Cu_(3)P-Ni_(2)P/CP-0.5 displays the practicability in an MEA system with an anion exchange membrane,affording the largest ammonia yield rate(RNH_(3))of 1.9 mmol·h^(−1)·cm^(−2),exceeding most of the electrocatalytic nitrate reduction electrocatalysts reported to date.The theoretical calculations and in-situ spectroscopy characterizations uncover that the formed heterointerface in Cu_(3)P-Ni_(2)P/CP is beneficial for promoting nitrate adsorption,activation,and conversion to ammonia through the successive hydrodeoxygenation pathway.
基金supported by the National Natural Science Foundation of China(Nos.22002013 and 52272193)the Fundamental Research Funds for the Central Universities(Nos.DUT22LAB602 and DUT20RC(3)021)+1 种基金Liaoning Revitalization Talents Program(No.XLYC2008032)China Postdoctoral Science Foundation(No.2023M740496)。
文摘Atomic transition metal–nitrogen–carbon electrocatalysts exhibit outstanding activity in various electrocatalytic reactions.The challenge lies in predicting the structure of the active center,which may undergo changes under applied potential and interact with reactants or intermediates.Advanced characterization techniques,particularly in-situ X-ray absorption spectroscopy(XAS),provide crucial insights into the structural evolution of the metal active center during the reaction.In this study,nitrate reduction to ammonia(NO_(3)RR)was selected as a model reaction,and we introduced in-situ XAS to reveal the structural evolution during the catalytic process.A novel single atom catalyst of iron loaded on three-dimensional nitrogen–carbon nanonetwork(designated as Fe SAC/NC)was successfully synthesized.We unraveled the structural transformations occurring as pyrrole-N_(4)-Fe transitions to pyrrole-N_(3)-Fe throughout the NO_(3)RR process.Notably,the Fe SAC/NC catalyst exhibited excellent catalytic activity,achieving a Faradaic efficiency of 98.2% and an ammonia generation rate of 22,515μg·h^(−1)·mgcat−1 at−0.8 V versus reversible hydrogen electrode.Theoretical calculations combined with in-situ spectroscopic characterization showed that pyrrole-N_(3)-Fe reduced the energy barrier from *NO to*NHO and improved the selectivity of ammonia.This provides a robust reference for the design of efficient nitrate-to-ammonia synthesis catalysts.
基金the National Natural Science Foundation of China(No.22204119)Science and Technology Plans of Tianjin(No.22ZYJDSS00070).
文摘Electrocatalytic nitrate reduction to ammonia(NO3−RR)for removing nitrate from wastewater is a promising but challengeable technology that is increasingly studied.Herein,we developed an efficient CuO_(x)and CoCuO_(x)composed hybrid catalyst(CoCuO_(x)@CuO_(x)/copper foam(CF)),characteristic of distinctive shell-core nanowires grown on CF substrate with CuO_(x)core and CoCuO_(x)shell.The built-in electric field formed at the interface of the CoO/Cu_(2)O heterostructure promotes NO3−adsorption by modulating the charge distribution at the interface,which greatly improves the ammonia yield rate and Faradaic efficiency.At−0.2 V vs.reversible hydrogen electrode(RHE),CoCuO_(x)@CuO_(x)/CF achieves not only an excellent ammonia yield rate of up to 519.1μg·h^(−1)·cm^(−2)and Faradaic efficiency of 99.83%at 1 mM NO3−concentration,but also excellent mechanical stabilities.This study provides a novel pathway to design electrocatalyst for the removal of nitrate from dilute nitric acid solutions(≤2 mM).
基金Funding for the present study from the National Basic Research Program of China(973 Program,No.2011CB710800)the Opening Foundation(2014)of Zhejiang Zanyu Technology Co.,Ltd
文摘The effect of the amount of precipitant ammonia on the Cu0/Cu＋ratio of Cu/Si O2 prepared by the deposition–precipitation method is investigated. Species at different preparation stages, resulted from the amount of ammonia used, are identified by the XRD and FTIR techniques. Chrysocolla together with either copper nitrate hydroxide or copper hydroxide coexist in the uncalcined catalysts. Upon calcination, the latter two species are converted to Cu O particles while chrysocolla remains. Following reduction, Cu O is transformed to metallic Cu and chrysocolla is converted to Cu2 O. The value of Cu0/Cu＋ratio can be evaluated using the peak areas in their TPR profiles. Hydrogenation of dimethyl oxalate（DMO） to ethylene glycol（EG） shows that the selectivity of EG depends on the Cu0/Cu＋ratio. Catalyst prepared with the addition of ammonia solution at n（NH3）/n（Cu2＋） = 0.9 for precipitation–deposition gains a more suitable Cu0/Cu＋ratio upon reduction and thus has a higher selectivity for EG.
基金supported by the National Natural Science Foundation of China(51902218,21972102,22101197,and 22202144)Jiangsu Provincial Graduate Scientific Research and Practice Innovation Plan Project(KYCX21_3016)+2 种基金the National Key Research and Development Program of China(2021YFA0910403)funded by the innovation platform for Academicians of Hainan ProvinceSuzhou Foreign Academician Workstation。
