The electrochemical nitrogen reduction reaction(eNRR)holds significant promise as a sustainable alternative to the conventional large-scale Haber Bosch process,offering a carbon footprint-free approach for ammonia syn...The electrochemical nitrogen reduction reaction(eNRR)holds significant promise as a sustainable alternative to the conventional large-scale Haber Bosch process,offering a carbon footprint-free approach for ammonia synthesis.While the process is thermodynamically feasible at ambient temperature and pressure,challenges such as the competing hydrogen evolution reaction,low nitrogen solubility in electrolytes,and the activation of inert dinitrogen(N_(2))gas adversely affect the performance of ammonia production.These hurdles result in low Faradaic efficiency and low ammonia production rate,which pose obstacles to the commercialisation of the process.Researchers have been actively designing and proposing various electrocatalysts to address these issues,but challenges still need to be resolved.A key strategy in electrocatalyst design lies in understanding the underlying mechanisms that govern the success or failure of the electrocatalyst in driving the electrochemical reaction.Through mechanistic studies,we gain valuable insights into the factors affecting the reaction,enabling us to propose optimised designs to overcome the barriers.This review aims to provide a comprehensive understanding of the various mechanisms involved in eNRR on the electrocatalyst surface.It delves into the various mechanisms such as dissociative,associative,Mars-van Krevelen,lithium-mediated nitrogen reduction and surface hydrogenation mechanisms of nitrogen reduction.By unravelling the intricacies of eNRR mechanisms and exploring promising avenues,we can pave the way for more efficient and commercially viable ammonia synthesis through this sustainable electrochemical process by designing an efficient electrocatalyst.展开更多
Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and i...Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO_(2)-free pure hydrogen.Herein,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs)with a total geometric area of 200 cm~2 on the anode side,which resulted in a hydrogen production rate of 25 L h~(-1).We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia electrolysis.Furthermore,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER).展开更多
Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineere...Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineered electrocatalyst plays a vital role in the realization of superior catalytic performance.Among various types of promising nanomaterials,metal–organic frameworks(MOFs)are competitive candidates for developing efficient electrocatalytic NH_(3) synthesis from simple nitrogen-containing molecules or ions,such as N_(2) and NO_(3)^(−).In this review,recent advances in the development of electrocatalysts derived from MOFs for the electrosynthesis of NH_(3) are collected,categorized,and discussed,including their application in the N_(2) reduction reaction(NRR)and the NO_(3)^(−)reduction reaction(NO3RR).Firstly,the fundamental principles are illustrated,such as plausible mechanisms of NH_(3) generation from N_(2) and NO_(3)^(−),the apparatus of corresponding electrocatalysis,parameters for evaluation of reaction efficiency,and detection methods of yielding NH_(3).Then,the electrocatalysts for NRR processes are discussed in detail,including pristine MOFs,MOF-hybrids,MOF-derived N-doped porous carbons,single atomic catalysts from pyrolysis of MOFs,and other MOF-related materials.Subsequently,MOF-related NO3RR processes are also listed and discussed.Finally,the existing challenges and prospects for the rational design and fabrication of electrocatalysts from MOFs for electrochemical NH_(3) synthesis are presented,such as the evolution of investigation methods with artificial intelligence,innovation in synthetic methods of MOF-related catalysts,advancement of characterization techniques,and extended electrocatalytic reactions.展开更多
Reaction dynamics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas-solid catalyst reactions and are crucial to the catalyst function.Supported noble metal nanocatalysts such as...Reaction dynamics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas-solid catalyst reactions and are crucial to the catalyst function.Supported noble metal nanocatalysts such as platinum are of interest in fuel cells and as diesel oxidation catalysts for pollution control,and practical ruthenium nanocatalysts are explored for ammonia synthesis.Graphite and graphitic carbons are of interest as supports for the nanocatalysts.Despite considerable literature on the catalytic processes on graphite and graphitic supports,reaction dynamics of the nanocatalysts on the supports in different reactive gas environments and operating temperatures at the single atom level are not well understood.Here we present real time in-situ observations and analyses of reaction dynamics of Pt in oxidation,and practical Ru nanocatalysts in ammonia synthesis,on graphite and related supports under controlled reaction environments using a novel in-situ environmental(scanning) transmission electron microscope with single atom resolution.By recording snapshots of the reaction dynamics,the behaviour of the catalysts is imaged.The images reveal single metal atoms,clusters of a few atoms on the graphitic supports and the support function.These all play key roles in the mobility,sintering and growth of the catalysts.The experimental findings provide new structural insights into atomic scale reaction dynamics,morphology and stability of the nanocatalysts.展开更多
Rapid addition of alcohols to 1,2,3-diazaphosphole 1 easily gave tricoordinated phosphorus compounds,which were sulfurized to tetracoordinated phosphorus compounds. When ethylene glycol and aminoethanol were used sepa...Rapid addition of alcohols to 1,2,3-diazaphosphole 1 easily gave tricoordinated phosphorus compounds,which were sulfurized to tetracoordinated phosphorus compounds. When ethylene glycol and aminoethanol were used separately to react with 1,the tricoordinated phosphorus compounds which formed,rearranged to pentacoordinated phosphorus compounds and the substituents at N_2 affected the rearrangement significantly.展开更多
The reaction mechanism of ammonia with formaldehyde was investigated by using the intrinsic reaction coordinate(IRC)method on the ab initio RHF/STO-3G basis set. our results indicate that the reaction proceeds in two ...The reaction mechanism of ammonia with formaldehyde was investigated by using the intrinsic reaction coordinate(IRC)method on the ab initio RHF/STO-3G basis set. our results indicate that the reaction proceeds in two stages:the first step yields the molecular complex and the second one is the rearrangement from molecular complex to the reaction proauct.展开更多
A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N(CH3)3]3 {PO4[MoO(O2)2]4} was utilized as the...A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N(CH3)3]3 {PO4[MoO(O2)2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.展开更多
Ambient electrocatalytic nitrogen fixation is an emerging technology for green ammonia synthesis,but the absence of optimized,stable and performant catalysts can render its practical application challenging.Herein,bim...Ambient electrocatalytic nitrogen fixation is an emerging technology for green ammonia synthesis,but the absence of optimized,stable and performant catalysts can render its practical application challenging.Herein,bimetallic NiCo boride nanoparticles confined in MXene are shown to accomplish highperformance nitrogen reduction electrolysis.Ta king advantage of the synergistic effect in specific compositions with unique electronic d and p orbits and typical architecture of rich nanosized particles embedded in the interconnected conductive network,the synthesized MXene@NiCoB composite demonstrates extensive improvements in nitrogen molecule chemisorption,active area exposure and charge transport.As a result,optimal NH3 yield rate of 38.7μg h^(-1) mgcat^(-1).and Faradaic efficiency of 6.92%are acquired in0.1 M Na_(2)SO_(4) electrolyte.Moreover,the great catalytic performance can be almost entirely maintained in the cases of repeatedly-cycled and long-term electrolysis.Theoretical investigations reveal that the nitrogen reduction reaction on MXene@NiCoB catalyst proceeds according to the distal pathway,with a distinctly-reduced energy barrier relative to the Co2B counterpart.This work may inspire a new route towards the rational catalyst design for the nitrogen reduction reaction.展开更多
Presently,ammonia is an ideal candidate for future clean energy.The Haber-Bosch process has been an essential ammonia production process,and it is one of the most important technological advancements since its inventi...Presently,ammonia is an ideal candidate for future clean energy.The Haber-Bosch process has been an essential ammonia production process,and it is one of the most important technological advancements since its invention,sustaining the explosive growth of military munitions industry and fertilizers in the first half of the 20th century.However,the process is facing great challenges:the growing need for ammonia and the demands of environmental protection.High energy consumption and high CO_(2) emissions greatly limit the application of the Haber-Bosch method,and increasing research efforts are devoted to"green"ammonia synthesis.Thermocatalytic,electrocatalytic,and photocatalytic ammonia production under mild conditions and the derived chemical looping and plasma ammonia production methods,have been widely developed.Electrocatalytic and photocatalytic methods,which use low fossil fuels,are naturally being considered as future directions for the development of ammonia production.Although their catalytic efficiency of ammonia generation is not yet sufficient to satisfy the actual demands,considerable progress has been made in terms of regulating structure and morphology of catalyst and improving preparation efficiency.The chemical looping approach of ammonia production differs from the thermocatalytic,electrocatalytic,and photocatalytic methods,and is the method of reusing raw materials.The plasma treatment approach alters the overall ammonia production approach and builds up a new avenue of development in combination with thermal,photocatalytic,and electrocatalytic methods as well.This review discusses several recent effective catalysts for different ammonia production methods and explores mechanisms as well as efficiency of these catalysts for catalytic N2fixation of ammonia.展开更多
Transfer hydrogenation(TH) with in situ generated hydrogen donor is of great importance in reduction reactions, and an alternative strategy to traditional hydrogenation processes involving pressurized molecular hydrog...Transfer hydrogenation(TH) with in situ generated hydrogen donor is of great importance in reduction reactions, and an alternative strategy to traditional hydrogenation processes involving pressurized molecular hydrogen. Ammonia borane(NH3BH3, AB) is a promising material of hydrogen storage, and it has attracted much attention in reductive organic transformations owing to its high activity, good atom economy, nontoxicity, sustainability, and ease of transport and storage. This review focuses on summarizing the recent progress of AB-mediated TH reactions of diverse substrates including nitro compounds, nitriles, imines, alkenes, alkynes, carbonyl compounds(ketones and aldehydes), carbon dioxide,and N-and O-heterocycles. Syntheses protocols(metal-containing and metal-free), the effect of reaction parameters, product distribution, and variation of reactivity are surveyed, and the mechanism of each reaction involving the action mode of AB as well as structure-activity relationships is discussed in detail. Finally, perspectives are presented to highlight the challenges and opportunities for AB-enabled TH reactions of unsaturated compounds.展开更多
Hydrogen-bonded organic frameworks(HOFs),an emerging porous macrocyclic materials linked by hydrogen-bond,hold potential for gas separation and storage,sensors,optical,and electrocatalysts.Here,HOF-based electrocataly...Hydrogen-bonded organic frameworks(HOFs),an emerging porous macrocyclic materials linked by hydrogen-bond,hold potential for gas separation and storage,sensors,optical,and electrocatalysts.Here,HOF-based electrocatalysts are rationally developed for nitrates reduction to ammonia,allowing not only to regulate wastewater pollution but also to accomplish carbon-neutral ammonia(NH_(3))synthesis.We preform high-throughput computational screening of thirty-six HOFs with various metals as active sites,denoted as HOF-M1,for nitrate reduction reaction(NO_(3)RR)toward NH_(3).We have implemented a hierarchical four-step screening strategy,and ultimately,HOF-Ti1 was selected based on its exceptional catalytic activity and selectivity in the NO_(3)RR process.Through additional analysis,we discovered that the d band center of the active metal sites serves as an effective parameter for designing and predicting the performance of HOFs in NO_(3)RR.This research not only showcases the immense potential of electrocatalysis in transforming NO_(3)RR into NH_(3)but also provides researchers with a compelling incentive to undertake further experimental investigations.展开更多
The electrocatalytic conversion of reactive nitrogen species to ammonia is a promising strategy for efficient NH_(3) synthesis.In this study,we reveal that the hybrid Cu^(+)/Cu~0 interface is catalytically active for ...The electrocatalytic conversion of reactive nitrogen species to ammonia is a promising strategy for efficient NH_(3) synthesis.In this study,we reveal that the hybrid Cu^(+)/Cu~0 interface is catalytically active for electrochemical ammonia synthesis from nitrate reduction.To maintain the hybrid Cu^(+)/Cu~0 state at negative reaction potentials,hydrophilic zeolite is used to modify Cu/Cu_(2)O electrocatalyst,which demonstrates an impressive NH_(3) production rate of 41.65 mg h^(-1) cm^(-2)with ~100% Faradaic efficiency of ammonia synthesis at-0.6 V vs.RHE.In-situ Raman spectroscopy unveil the high activity originates from the zeolite reconstruction at the electrode–electrolyte interface,which protects the valence state of Cu~0/Cu^(+) site under negative potential and promotes electrochemical activity towards NH_(3) synthesis.展开更多
Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to i...Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.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
针对锂介导合成氨(LM-NRR)过程中存在的水污染问题,通过对比实验及扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)等表征手段,探讨了含水量对LM-NRR体系的性能影响及其在反应界面中的作用机理。结果表明,无水条件下的L...针对锂介导合成氨(LM-NRR)过程中存在的水污染问题,通过对比实验及扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)等表征手段,探讨了含水量对LM-NRR体系的性能影响及其在反应界面中的作用机理。结果表明,无水条件下的LM-NRR体系具有较好的氨合成性能,在反应时间为120 min、N2流速为4 m L·min^(-1)、电流密度为3 m A·cm^(-2)条件下的氨合成速率可达0.0124μg·s^(-1)·cm^(-2),法拉第效率为7.05%。含水量对LM-NRR体系的影响显著,会极大地降低体系的氨合成速率及法拉第效率。这主要是由于反应界面上的水会加剧竞争性析氢反应(HER)、促进电解质中Li BF_(4)的水解以及钝化表面活性锂位点,进而降低了体系的氨反应活性。展开更多
基金the Science and Engineering Research Board(SERB),Government of India for funding this work(Sanction No.EEQ/2021/001116)。
文摘The electrochemical nitrogen reduction reaction(eNRR)holds significant promise as a sustainable alternative to the conventional large-scale Haber Bosch process,offering a carbon footprint-free approach for ammonia synthesis.While the process is thermodynamically feasible at ambient temperature and pressure,challenges such as the competing hydrogen evolution reaction,low nitrogen solubility in electrolytes,and the activation of inert dinitrogen(N_(2))gas adversely affect the performance of ammonia production.These hurdles result in low Faradaic efficiency and low ammonia production rate,which pose obstacles to the commercialisation of the process.Researchers have been actively designing and proposing various electrocatalysts to address these issues,but challenges still need to be resolved.A key strategy in electrocatalyst design lies in understanding the underlying mechanisms that govern the success or failure of the electrocatalyst in driving the electrochemical reaction.Through mechanistic studies,we gain valuable insights into the factors affecting the reaction,enabling us to propose optimised designs to overcome the barriers.This review aims to provide a comprehensive understanding of the various mechanisms involved in eNRR on the electrocatalyst surface.It delves into the various mechanisms such as dissociative,associative,Mars-van Krevelen,lithium-mediated nitrogen reduction and surface hydrogenation mechanisms of nitrogen reduction.By unravelling the intricacies of eNRR mechanisms and exploring promising avenues,we can pave the way for more efficient and commercially viable ammonia synthesis through this sustainable electrochemical process by designing an efficient electrocatalyst.
基金supported by the research program funded by the TKG Huchemssupported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resources from the Ministry of Trade,Industry&Energy,Republic of Korea(20213030040590)supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(2021R1A5A1028138)。
文摘Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO_(2)-free pure hydrogen.Herein,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs)with a total geometric area of 200 cm~2 on the anode side,which resulted in a hydrogen production rate of 25 L h~(-1).We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia electrolysis.Furthermore,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER).
基金support from the Natural Science Foundation of Liaoning Province(general program)(2020-MS-137)T.J.White would like to thank the MOE2019-T2-2-032 grant and Monetary Academic Resources for Research Grant 001561-00001 in Nanyang Technological University,Singapore+9 种基金T.Ma would like to thank the National Natural Science Foundation of China(Nos.52071171,52202248)Liaoning BaiQianWan Talents Program(LNBQW2018B0048)Shenyang Science and Technology Project(21-108-9-04)Australian Research Council(ARC)through Future Fellowship(FT210100298,FT210100806)Discovery Project(DP220100603)Linkage Project(LP210100467,LP210200504,LP210200345,LP220100088)Industrial Transformation Training Centre(IC180100005)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)F.Wei would like to thank the A^(*)STAR career development fund C210112054Singapore structural metal alloy program grant No.A18b1B0061.A.K.Cheetham would like to thank the Ras al Khaimah Centre for Advanced Materials.
文摘Electrocatalytic synthesis under mild conditions has become increasingly important as one of the practical alternatives for industrial applications,especially for the green ammonia(NH_(3))industry.A properly engineered electrocatalyst plays a vital role in the realization of superior catalytic performance.Among various types of promising nanomaterials,metal–organic frameworks(MOFs)are competitive candidates for developing efficient electrocatalytic NH_(3) synthesis from simple nitrogen-containing molecules or ions,such as N_(2) and NO_(3)^(−).In this review,recent advances in the development of electrocatalysts derived from MOFs for the electrosynthesis of NH_(3) are collected,categorized,and discussed,including their application in the N_(2) reduction reaction(NRR)and the NO_(3)^(−)reduction reaction(NO3RR).Firstly,the fundamental principles are illustrated,such as plausible mechanisms of NH_(3) generation from N_(2) and NO_(3)^(−),the apparatus of corresponding electrocatalysis,parameters for evaluation of reaction efficiency,and detection methods of yielding NH_(3).Then,the electrocatalysts for NRR processes are discussed in detail,including pristine MOFs,MOF-hybrids,MOF-derived N-doped porous carbons,single atomic catalysts from pyrolysis of MOFs,and other MOF-related materials.Subsequently,MOF-related NO3RR processes are also listed and discussed.Finally,the existing challenges and prospects for the rational design and fabrication of electrocatalysts from MOFs for electrochemical NH_(3) synthesis are presented,such as the evolution of investigation methods with artificial intelligence,innovation in synthetic methods of MOF-related catalysts,advancement of characterization techniques,and extended electrocatalytic reactions.
基金the Engineering and Physical Science Research Council(EPSRC),U.K.for the award of a research grant EP/J0118058/1 and postdoctoral research assistantships(PDRAs) to M.R.W.and R.W.M.from the grant。
文摘Reaction dynamics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas-solid catalyst reactions and are crucial to the catalyst function.Supported noble metal nanocatalysts such as platinum are of interest in fuel cells and as diesel oxidation catalysts for pollution control,and practical ruthenium nanocatalysts are explored for ammonia synthesis.Graphite and graphitic carbons are of interest as supports for the nanocatalysts.Despite considerable literature on the catalytic processes on graphite and graphitic supports,reaction dynamics of the nanocatalysts on the supports in different reactive gas environments and operating temperatures at the single atom level are not well understood.Here we present real time in-situ observations and analyses of reaction dynamics of Pt in oxidation,and practical Ru nanocatalysts in ammonia synthesis,on graphite and related supports under controlled reaction environments using a novel in-situ environmental(scanning) transmission electron microscope with single atom resolution.By recording snapshots of the reaction dynamics,the behaviour of the catalysts is imaged.The images reveal single metal atoms,clusters of a few atoms on the graphitic supports and the support function.These all play key roles in the mobility,sintering and growth of the catalysts.The experimental findings provide new structural insights into atomic scale reaction dynamics,morphology and stability of the nanocatalysts.
文摘Rapid addition of alcohols to 1,2,3-diazaphosphole 1 easily gave tricoordinated phosphorus compounds,which were sulfurized to tetracoordinated phosphorus compounds. When ethylene glycol and aminoethanol were used separately to react with 1,the tricoordinated phosphorus compounds which formed,rearranged to pentacoordinated phosphorus compounds and the substituents at N_2 affected the rearrangement significantly.
基金This work was partly supported by the National Science Foundation of China
文摘The reaction mechanism of ammonia with formaldehyde was investigated by using the intrinsic reaction coordinate(IRC)method on the ab initio RHF/STO-3G basis set. our results indicate that the reaction proceeds in two stages:the first step yields the molecular complex and the second one is the rearrangement from molecular complex to the reaction proauct.
文摘A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N(CH3)3]3 {PO4[MoO(O2)2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.
基金financially supported by the National Natural Science Foundation of China(No.21878063)Key Program of Shandong Provincial Natural Science Foundation(No.ZR2020KB011)+2 种基金Taishan Scholars Program of Shandong Province(No.tsqn201909119)financial support from the Flemish Government through the Moonshot cSBO project P2C(HBC.2019.0108)through long-term structural funding(Methusalem CASAS2,Meth/15/04)。
文摘Ambient electrocatalytic nitrogen fixation is an emerging technology for green ammonia synthesis,but the absence of optimized,stable and performant catalysts can render its practical application challenging.Herein,bimetallic NiCo boride nanoparticles confined in MXene are shown to accomplish highperformance nitrogen reduction electrolysis.Ta king advantage of the synergistic effect in specific compositions with unique electronic d and p orbits and typical architecture of rich nanosized particles embedded in the interconnected conductive network,the synthesized MXene@NiCoB composite demonstrates extensive improvements in nitrogen molecule chemisorption,active area exposure and charge transport.As a result,optimal NH3 yield rate of 38.7μg h^(-1) mgcat^(-1).and Faradaic efficiency of 6.92%are acquired in0.1 M Na_(2)SO_(4) electrolyte.Moreover,the great catalytic performance can be almost entirely maintained in the cases of repeatedly-cycled and long-term electrolysis.Theoretical investigations reveal that the nitrogen reduction reaction on MXene@NiCoB catalyst proceeds according to the distal pathway,with a distinctly-reduced energy barrier relative to the Co2B counterpart.This work may inspire a new route towards the rational catalyst design for the nitrogen reduction reaction.
基金the National Natural Science Foundation of China (22276194)Institute of Energy of Hefei comprehensive National Science Center (21KZZ501 and 21KZS201)+2 种基金the Presidential Foundation of Hefei Institutes of Physical Science, Chinese Academy of Sciences (YZJJZX202019)funded by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah, Saudi Arabia under grant (KEP-PhD: 65-2471443)DSR technical and financial support.
文摘Presently,ammonia is an ideal candidate for future clean energy.The Haber-Bosch process has been an essential ammonia production process,and it is one of the most important technological advancements since its invention,sustaining the explosive growth of military munitions industry and fertilizers in the first half of the 20th century.However,the process is facing great challenges:the growing need for ammonia and the demands of environmental protection.High energy consumption and high CO_(2) emissions greatly limit the application of the Haber-Bosch method,and increasing research efforts are devoted to"green"ammonia synthesis.Thermocatalytic,electrocatalytic,and photocatalytic ammonia production under mild conditions and the derived chemical looping and plasma ammonia production methods,have been widely developed.Electrocatalytic and photocatalytic methods,which use low fossil fuels,are naturally being considered as future directions for the development of ammonia production.Although their catalytic efficiency of ammonia generation is not yet sufficient to satisfy the actual demands,considerable progress has been made in terms of regulating structure and morphology of catalyst and improving preparation efficiency.The chemical looping approach of ammonia production differs from the thermocatalytic,electrocatalytic,and photocatalytic methods,and is the method of reusing raw materials.The plasma treatment approach alters the overall ammonia production approach and builds up a new avenue of development in combination with thermal,photocatalytic,and electrocatalytic methods as well.This review discusses several recent effective catalysts for different ammonia production methods and explores mechanisms as well as efficiency of these catalysts for catalytic N2fixation of ammonia.
基金financially supported by the National Natural Science Foundation of China (21908033,21576059,21666008)Fok Ying-Tong Education Foundation (161030)+1 种基金the Program of Introducing Talents of Discipline to Universities of China (111 Program,D20023)Guizhou Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules ([2020]004)。
文摘Transfer hydrogenation(TH) with in situ generated hydrogen donor is of great importance in reduction reactions, and an alternative strategy to traditional hydrogenation processes involving pressurized molecular hydrogen. Ammonia borane(NH3BH3, AB) is a promising material of hydrogen storage, and it has attracted much attention in reductive organic transformations owing to its high activity, good atom economy, nontoxicity, sustainability, and ease of transport and storage. This review focuses on summarizing the recent progress of AB-mediated TH reactions of diverse substrates including nitro compounds, nitriles, imines, alkenes, alkynes, carbonyl compounds(ketones and aldehydes), carbon dioxide,and N-and O-heterocycles. Syntheses protocols(metal-containing and metal-free), the effect of reaction parameters, product distribution, and variation of reactivity are surveyed, and the mechanism of each reaction involving the action mode of AB as well as structure-activity relationships is discussed in detail. Finally, perspectives are presented to highlight the challenges and opportunities for AB-enabled TH reactions of unsaturated compounds.
基金financial support from the National Key R&D Program of China(Grant 2022YFA1504000)the National Natural Science Foundation of China(Grants 22125205,22002166,22272176,22072146 and 22002158)+2 种基金the Fundamental Research Funds for the Central Universities(20720220008)the Dalian National Laboratory for Clean Energy(DNL202007,DNL201923)the financial support from the CAS Youth Innovation Promotion(Grant Y201938)。
文摘Hydrogen-bonded organic frameworks(HOFs),an emerging porous macrocyclic materials linked by hydrogen-bond,hold potential for gas separation and storage,sensors,optical,and electrocatalysts.Here,HOF-based electrocatalysts are rationally developed for nitrates reduction to ammonia,allowing not only to regulate wastewater pollution but also to accomplish carbon-neutral ammonia(NH_(3))synthesis.We preform high-throughput computational screening of thirty-six HOFs with various metals as active sites,denoted as HOF-M1,for nitrate reduction reaction(NO_(3)RR)toward NH_(3).We have implemented a hierarchical four-step screening strategy,and ultimately,HOF-Ti1 was selected based on its exceptional catalytic activity and selectivity in the NO_(3)RR process.Through additional analysis,we discovered that the d band center of the active metal sites serves as an effective parameter for designing and predicting the performance of HOFs in NO_(3)RR.This research not only showcases the immense potential of electrocatalysis in transforming NO_(3)RR into NH_(3)but also provides researchers with a compelling incentive to undertake further experimental investigations.
基金the support from the Fundamental Research Funds for the Central Universities (2022LHJH01-03, 2022ZFJH04, 2022QZJH14)Pioneer R&D Program of Zhejiang Province (2022C03040)+1 种基金the Ecological civilization project, Zhejiang Universitythe support from A Project Supported by Scientific Research Fund of Zhejiang University (XY2022013)。
文摘The electrocatalytic conversion of reactive nitrogen species to ammonia is a promising strategy for efficient NH_(3) synthesis.In this study,we reveal that the hybrid Cu^(+)/Cu~0 interface is catalytically active for electrochemical ammonia synthesis from nitrate reduction.To maintain the hybrid Cu^(+)/Cu~0 state at negative reaction potentials,hydrophilic zeolite is used to modify Cu/Cu_(2)O electrocatalyst,which demonstrates an impressive NH_(3) production rate of 41.65 mg h^(-1) cm^(-2)with ~100% Faradaic efficiency of ammonia synthesis at-0.6 V vs.RHE.In-situ Raman spectroscopy unveil the high activity originates from the zeolite reconstruction at the electrode–electrolyte interface,which protects the valence state of Cu~0/Cu^(+) site under negative potential and promotes electrochemical activity towards NH_(3) synthesis.
基金supported by the Climate Change Response Project (NRF-2019M1A2A2065612)the Brainlink Project (NRF2022H1D3A3A01081140)+3 种基金the NRF-2021R1A4A3027878 and the No. RS-2023-00212273 funded by the Ministry of Science and ICT of Korea via National Research Foundationresearch funds from Hanhwa Solutions Chemicals (1.220029.01)UNIST (1.190013.01)supported by the Institute for Basic Science (IBS-R019-D1)。
文摘Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.
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).
文摘针对锂介导合成氨(LM-NRR)过程中存在的水污染问题,通过对比实验及扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)等表征手段,探讨了含水量对LM-NRR体系的性能影响及其在反应界面中的作用机理。结果表明,无水条件下的LM-NRR体系具有较好的氨合成性能,在反应时间为120 min、N2流速为4 m L·min^(-1)、电流密度为3 m A·cm^(-2)条件下的氨合成速率可达0.0124μg·s^(-1)·cm^(-2),法拉第效率为7.05%。含水量对LM-NRR体系的影响显著,会极大地降低体系的氨合成速率及法拉第效率。这主要是由于反应界面上的水会加剧竞争性析氢反应(HER)、促进电解质中Li BF_(4)的水解以及钝化表面活性锂位点,进而降低了体系的氨反应活性。