Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct c...Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.展开更多
Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction(HER)but the effect of the crystal phase engineering of supports on their performance remains unclear.Here,the impact o...Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction(HER)but the effect of the crystal phase engineering of supports on their performance remains unclear.Here,the impact of the crystal phase of the support on the catalytic activity of Ru was probed by anchoring Ru nanoparticles onto precisely synthesized hexagonal(WO_(3)-H),orthorhombic(WO_(3)-O),and monoclinic(WO_(3)-M)supports followed by thorough evaluation for HER.Among them,WO_(3)-H demonstrated superior performance by providing enhanced Ru anchoring and uniform dispersion,maximizing active site availability.A critical finding is the small work function difference(ΔW_(F))between Ru and WO_(3)-H,which minimizes interfacial charge accumulation and facilitates efficient hydrogen spillover,thereby accelerating HER kinetics.In contrast,WO_(3)-O and WO_(3)-M exhibited largerΔW_(F)and less effective Ru dispersion,resulting in a larger hydrogen spillover barrier and suboptimal hydrogen adsorption/desorption dynamics.As a result,Ru/WO_(3)-H exhibited the best performance,achieving an overpotential of 43.8 mV at 10 mA cm^(-2)and a Tafel slope of 49.1 mV dec^(-1).This work highlights the critical role of the crystal phase in optimizing the intrinsic catalytic activity of catalysts,offering new insights for designing efficient HER catalysts.展开更多
With the advent of the digital economy,there has been a rapid proliferation of small-scale Internet data centers(SIDCs).By leveraging their spatiotemporal load regulation potential through data workload balancing,aggr...With the advent of the digital economy,there has been a rapid proliferation of small-scale Internet data centers(SIDCs).By leveraging their spatiotemporal load regulation potential through data workload balancing,aggregated SIDCs have emerged as promising demand response(DR)resources for future power distribution systems.This paper presents an innovative framework for assessing capacity value(CV)by aggregating SIDCs participating in DR programs(SIDC-DR).Initially,we delineate the concept of CV tailored for aggregated SIDC scenarios and establish a metric for the assessment.Considering the effects of the data load dynamics,equipment constraints,and user behavior,we developed a sophisticated DR model for aggregated SIDCs using a data network aggregation method.Unlike existing studies,the proposed model captures the uncertainties associated with end tenant decisions to opt into an SIDC-DR program by utilizing a novel uncertainty modeling approach called Z-number formulation.This approach accounts for both the uncertainty in user participation intentions and the reliability of basic information during the DR process,enabling high-resolution profiling of the SIDC-DR potential in the CV evaluation.Simulation results from numerical studies conducted on a modified IEEE-33 node distribution system confirmed the effectiveness of the proposed approach and highlighted the potential benefits of SIDC-DR utilization in the efficient operation of future power systems.展开更多
Interfacial electronic structure modulation of nickel-based electrocata-lysts is significant in boosting energy-conversion-relevant urea oxidation reaction(UOR).Herein,porous carbon nanofibers confined mixed Ni-based ...Interfacial electronic structure modulation of nickel-based electrocata-lysts is significant in boosting energy-conversion-relevant urea oxidation reaction(UOR).Herein,porous carbon nanofibers confined mixed Ni-based crystal phases of Ni_(2)P and NiF_(2) are developed via fluorination and phosphorization of Ni coated carbon nanofiber(Ni_(2)P/NiF_(2)/PCNF),which possess sufficient mesoporous and optimized Gibbs adsorption free energy by mixed phase-induced charge redistribution.This novel system further reduces the reaction energy barrier and improves the reaction activity by addressing the challenges of low intrinsic activity,difficulty in active site formation,and insufficient synergism.A considerably high current density of 254.29 mA cm^(-2) is reached at 1.54 V versus reversible hydrogen electrode on a glass carbon electrode,and the cell voltage requires 1.39 V to get 10 mA cm^(-2) in hydrogen generation,with very good stability,about 190 mV less than that of the traditional water electrolysis.The facile active phase formation and high charge transfer ability induced by asymmetric charge redistribution are found in the interface,where the urea molecules tend to bond with Ni atoms on the surface of heterojunction,and the rate-determining step is changed from CO_(2) desorption to the fourth H-atom deprotonation.The work reveals a novel catalyst system by interfacial charge redistribution induced by high bond polarity for energy-relevant catalysis reactions.展开更多
The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of ...The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of Ru nanoparticles(NPs) anchored on a two-dimensionally ordered MoSe_(2) nanosheet-embedded mesoporous hollow carbon spheres surface(Ru/MoSe_(2)@MHCS) for the largely boosted hydrogen evolution reaction(HER) performance. The combined advantages from the conductive support, oxyphilic MoSe_(2), and Ru active sites imparted a strong synergistic effect and charge redistribution in the Ru periphery which induced high catalytic activity, stability, and kinetics for HER. Specifically, the obtained Ru/MoSe_(2)@MHCS required a small overpotential of 25.5 and 38.4 mV to drive the kinetic current density of 10 mA cm^(-2)both in acid and alkaline media, respectively, which was comparable to that of the Pt/C catalyst. Experimental and theoretical results demonstrated that the charge transfer from MoSe_(2) to Ru NPs enriched the electronic density of Ru sites and thus facilitated hydrogen adsorption and water dissociation. The current work showed the significant interfacial engineering in Ru-based catalysts development and catalysis promotion effect understanding via the metal-support interaction.展开更多
Bi-functional electrocatalysts for acid overall water splitting reactions are crucial but still challenging to the development of proton exchange membrane water electrolysis.Herein,an efficient bi-functional catalyst ...Bi-functional electrocatalysts for acid overall water splitting reactions are crucial but still challenging to the development of proton exchange membrane water electrolysis.Herein,an efficient bi-functional catalyst of Ir/MoS_(2) nanoflowers(Ir/MoS_(2) NFs) catalyst was reported for acidic water electrolysis which can be constructed by coupling three-dimensionally interconnected MoS_(2) NFs with ultrafine Ir nanoparticles.A more suitable adsorption ability for the H* and *OOH intermediates was revealed,where the Ir sites were proposed as the main active center and MoS_(2) promoted the charge relocation to electronically modify the interfacial structure.The significant interfacial charge redistribution between the MoS_(2) NFs and the Ir active sites synergistically induced excellent catalytic activity and stability for the water electrolysis reaction.Specifically,the catalyst required overpotentials of 270 and 35 mV to reach a kinetic current density of 10 mA cm^(-2)for OER and HER,respectively,loading on the glass carbon electrode,with high catalytic kinetics,stability,and catalytic efficiency.A two-electrode system constructed by Ir/MoS_(2) NFs drove 10 mA cm^(-2)at a cell voltage of 1.55 V,about 70 mV lower than that of the commercial Pt/C||IrO_(2) system.In addition,partial surface oxidation of Ir nanoparticles to generate high-valent Ir species was also found significant to accelerate OER.The enhanced catalytic performance was attributed to the strong metal-support interaction in the Ir/MoS_(2) NFs catalyst system that changed the electronic structure of Ir metal and promoted the synergistic catalytic effect between Ir and MoS_(2) NFs.The work presented a novel platform of Ir-catalyst for proton exchange membrane water electrolysis.展开更多
Improving the catalytic efficiency and anti-poisoning ability of Pt-based catalysts is very critical in methanol electrolysis technology for high-purity hydrogen generation.Herein,the nitrogen-doped carbon polyhedrons...Improving the catalytic efficiency and anti-poisoning ability of Pt-based catalysts is very critical in methanol electrolysis technology for high-purity hydrogen generation.Herein,the nitrogen-doped carbon polyhedrons-encapsulated Mop(MoP@NC)supported Pt nanoparticles were demonstrated to be effective for methanol electrolysis resulting from the combined advantages.The nitrogen-doped carbon polyhedrons not only greatly enhanced the conductivity but also effectively prevented the aggregation of MoP to offer Pt anchoring sites.The electronic structure modification of Pt from their interaction reduced the adsorption energy of co^(*),resulting in good cO-poisoning resistance and accelerated reaction kinetics.Specifically,Pt-MoP@NC exhibited the highest peak current density of 106.4 mA.cm^(-2) for methanol oxidation and a lower overpotential of 28 mV at 10 mA.cm^(-2) for hydrogen evolution.Energy-saving hydrogen production from methanol electrolysis was demonstrated in the two-electrode systems assembled by Pt-MoP@NC which required a low cell voltage of 0.65 V to reach a kinetic current density of 10 mA.cm-on the glass carbon system,about 1.02 V less than thatofwaterelectrolysis.展开更多
Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced ...Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced by the variedly reported performance for the different Fe Ni structures.Herein,we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor.Driven by the complicated and compromised atmosphere,namely,the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe_(2)O_(3)and FeNi_(3)alloy,and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples.The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states,and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier.The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.展开更多
化石燃料的大量消耗所带来的全球性挑战推动人们大力发展清洁和可持续的能源.氢能作为一种绿色、无污染的能源载体,是能源向绿色经济转换的关键,而利用可再生能源进行的电解水制氢被认为是实现绿色制氢的最佳选择.然而由于析氧反应(OER...化石燃料的大量消耗所带来的全球性挑战推动人们大力发展清洁和可持续的能源.氢能作为一种绿色、无污染的能源载体,是能源向绿色经济转换的关键,而利用可再生能源进行的电解水制氢被认为是实现绿色制氢的最佳选择.然而由于析氧反应(OER)的氧化电位(1.23 V)较高,动力学缓慢,实际水电解需要更多的能量输入.具有低氧化电位的甲醇辅助水电解(0.016 V)可以匹配可再生能源实现低能耗电解制氢,受到了广泛关注.开发高效的用于催化甲醇氧化(MOR)和析氢反应(HER)的双功能催化剂是实现这一愿景的前提.传统的Pt基催化剂容易受到阳极侧MOR过程中产生的CO中间体毒化,严重影响甲醇辅助水电解制氢的效率.为了提升Pt基催化剂的催化活性和稳定性,一种有效的策略是引入合适的功能组分来促进催化反应.例如,贵金属颗粒和亲氧化成分(如过渡金属氧化物和磷化物)之间的金属-载体相互作用可以有效提高Pt基催化剂的抗CO中毒能力.过渡金属硒化物由于其优良的金属性和亲氧性作为催化促进剂受到越来越多的关注.硒化钼(MoSe_(2))具有良好的稳定性和导电性并且其2H相中的不饱和边缘具有水活化和解离活性,同时其吸附H原子的吉布斯自由能(ΔGH^(*))接近于零.考虑到MoSe_(2)的高水活化/解离能力,本文成功制备了二维MoSe_(2)纳米片负载的Pt纳米粒子复合催化剂(Pt/MoSe_(2))用于高效甲醇电解制氢.密度泛函理论计算表明,亲氧组分MoSe_(2)显著优化了CO^(*)和H^(*)在Pt表面的吸附能,从而大大提高了甲醇辅助水电解的活性和稳定性.其中,Pt/MoSe_(2)的甲醇氧化峰值电流密度为67.8 m Acm^(-2),是商业Pt/C催化剂的2.5倍;在10 m A·cm^(-2)的电流密度下,HER的过电位低至32 m V.由Pt/MoSe_(2)|Pt/MoSe_(2)组装的两电极电解槽驱动10 m A·cm^(-2)的电流密度仅需要0.67 V的电压,与相同条件下的水电解相比节省了约1.09 V的电池电压,大大降低了能量输入.催化性能的提升可以归因于改善的电荷转移以及Pt与亲氧MoSe_(2)之间的金属-载体相互作用,该相互作用使得Pt从MoSe_(2)载体上得到了部分电子,增加了Pt周围的电子密度,使得邻近Pt的d带中心下移,从而通过削弱CO-Pt键进而增强了Pt位点的抗CO中毒能力.综上,本文对开发用于甲醇辅助水电解制氢的新型双功能催化剂具有借鉴意义.展开更多
Efficient heterogeneous catalysts play a very important role in the value‐updated green hydrogen production from urea‐containing wastewater.Herein,NiSe_(2)/MoSe_(2)heterostructured catalyst with optimized interfacia...Efficient heterogeneous catalysts play a very important role in the value‐updated green hydrogen production from urea‐containing wastewater.Herein,NiSe_(2)/MoSe_(2)heterostructured catalyst with optimized interfacial electron redistribution and urea adsorption energies via a strong built‐in electric field was demonstrated effective for the urea‐assisted water splitting reactions.Efficient catalytic performance was found on NiSe_(2)/MoSe_(2)hybrid microsphere owing to the combined merits such as the unique structure features,the strong synergetic coupling effects,the increased active sites,and the high amount of intrinsic Ni^(3+)species.Excellent urea oxidation activity was found to drive 10 mA cm^(‒2)at the potential of 1.33 V when loaded on the glassy carbon electrode,and a cell voltage of 1.47 V was required in the NiSe_(2)/MoSe_(2)||Pt/C urea‐water electrolyzer to drive 10 mA cm^(‒2),about 220 mV less than that of water electrolysis,indicating a less energy consumption technique during the electrolysis.The spectroscopic and theoretical analysis revealed the effective synergy of the Ni-Se bond and Mo-Se bond that would be promising for efficient catalyst system construction.展开更多
Methanol-assisted water electrolysis presents a promising yet challenging technique for electrochemical hydrogen production,as limited by the easy poisoning issue of Pt active sites.In this study,we successfully synth...Methanol-assisted water electrolysis presents a promising yet challenging technique for electrochemical hydrogen production,as limited by the easy poisoning issue of Pt active sites.In this study,we successfully synthesized an efficient bifunctional catalyst composed of three-dimensional(3D)flower-like MoTe_(2) embedded nitrogen-doped carbon(NC)nanospheres,assembled by nanosheets,to support Pt nanoparticles(Pt-MoTe_(2)/NC)for methanol-assisted water electrolysis.This innovative Pt-MoTe_(2)/NC catalyst demonstrated superior catalytic performance targeting both hydrogen evolution reaction(HER)and methanol oxidation reaction(MOR)due to the strong metal-support interaction and the promotional effect of oxophilic molybdenum telluride.In situ infrared spectroscopy and CO stripping measurements revealed their excellent anti-poisoning ability.In particular,the onset potential of CO oxidation decreased by 130 mV relative to the standard Pt/C electrode.Theoretical calculations indicated the proper H*adsorption energy for HER and weakened CO adsorption energy for MOR in the optimized electronic structure.Therefore,the Pt-MoTe_(2)/NC electrode achieved the highest forward peak current density(76.6 mA·cm^(−2))for MOR,approximately 2.8-fold that of the commercial Pt/C,and only 34 mV was needed to deliver 10 mA·cm^(−2) for HER in acidic electrolyte.When employed as the bifunctional electrode in methanol electrolysis,Pt-MoTe_(2)/NC enabled efficient hydrogen generation with good stability,requiring merely 0.65 V to achieve 10 mA·cm^(−2),approximately 1090 mV less than traditional water electrolysis.This work presents an anti-poisoning catalyst in energy-saving hydrogen production from methanol electrolysis.展开更多
Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojuncti...Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojunction catalyst confined in carbon nanofiber with spontaneous charge redistribution driven by high valent metal,which promotes the adsorption and transformation of intermediates and greatly reduces the reaction energy barrier for urea oxidation.The heterojunction catalyst promotes the formation of Ni^(3+)active species and accelerates the fracture of the C-N bond by enhancing selective adsorption of-NH_(2)and C=O groups in binding urea molecules driven by the spontaneous formation of nucleophilic and electrophilic sites.The catalyst achieves a low kinetic current density of 10 mA cm^(-2)at 1.35 V with a cell voltage for urea electrolysis of just 1.47 V and good durability over 60 h.Density-functional theory and in-situ spectral observation reveal that the high valent Mo promoted the 3d orbit of Ni approaching the Fermi level by adjusting the electronic structure,which enhanced spontaneous urea dehydrogenation and reduced the energy barrier for^(*)COO desorption.This study highlights the effectiveness of modulating the interfacial electronic structure to improve energy conversion efficiency.展开更多
Improving the slow kinetics of alkaline hydrogen electrode reactions, involving hydrogen oxidation and evolution reactions(HOR/HER) is highly desirable for accelerating the commercialization of alkaline exchange membr...Improving the slow kinetics of alkaline hydrogen electrode reactions, involving hydrogen oxidation and evolution reactions(HOR/HER) is highly desirable for accelerating the commercialization of alkaline exchange membrane-based fuel cells(AEMFCs) and water electrolyzers(AEMWEs). However, fundamental understanding of the mechanism for HOR/HER catalysis under alkaline media is still debatable. Here we develop an amorphous tungsten oxide clusters modified iridium-tungsten nanocrystallines(Ir WOx)which exhibited by far the highest exchange current density and mass activity, about three times higher than the commercial Pt/C toward alkaline HOR/HER. Density functional theory(DFT) calculations reveal the WOxclusters act as a pivotal role to boost reversible hydrogen electrode reactions in alkaline condition but via different mechanisms, which are, hydrogen binding energy(HBE) mechanism for HOR and bifunctional mechanism for HER. This work is expected to promote our fundamental understanding about the alkaline HOR/HER catalysis and provide a new avenue for rational design of highly efficient electrocatalysts toward HOR/HER under alkaline electrolytes.展开更多
Exploring efficient and economical electrocatalysts and understanding the mechanism for alkaline hydrogen oxidation reaction(HOR)are crucial to facilitate the development of alkaline polymer electrolyte fuel cells(APE...Exploring efficient and economical electrocatalysts and understanding the mechanism for alkaline hydrogen oxidation reaction(HOR)are crucial to facilitate the development of alkaline polymer electrolyte fuel cells(APEFCs).Herein,Ru_(2)P was synthesized and used as an anodic HOR electrocatalyst for APEFC,achieving a peak power density of 1.3 W cm^(−2),the highest value among Pt-free anode electrocatalysts reported under the same conditions.Fromthe density functional theory(DFT)calculations and experimental results,it was found that besides the optimized hydrogen binding energy,the enhanced adsorption strength of oxygenated species(OH*)and the reduced work function of Ru_(2)P contributed to the enhanced HOR performance.The normalized exchange current densities of Ru_(2)P/C were 0.37 mA cm_(ECSA)^(−2) and 0.27 mAμgRu^(−1),respectively,both approximately three times higher than those of Ru when conducted in the rotating disk electrode(RDE)system.Our work provides a new pathway for exploring highly active Pt-free HOR electrocatalysts and expanding the family of anodic electrocatalysts for APEFCs.展开更多
Methanol as an important hydrogen-rich fuel has received increasing attention in energy storage and conversion techniques,and energy release can be realized in the methanol oxidation reaction(MOR)process.Note that hig...Methanol as an important hydrogen-rich fuel has received increasing attention in energy storage and conversion techniques,and energy release can be realized in the methanol oxidation reaction(MOR)process.Note that highly efficient catalysts are still required to drive methanol oxidation,and the Ni-based catalysts have received intensive attention due to their facile active site generation based on the electrochemical-chemical oxidation mechanisms.In light of the significant advances made recently,herein,we reviewed the recent advances of Ni-based catalysts for methanol oxidation in the alkaline medium.The fundamental of methanol oxidation in the alkaline medium was first presented,and then the catalyst design principles including synergistic effect,electronic effect,defect construction,doping effect,as well as surface reconstruction were presented;and the advances of various Ni-based catalysts for MOR are summarized and discussed by combining with some typical examples.The problems and challenges were also concluded for the Ni-based catalyst fabrication,the performance evaluation,and their application.We believe that the summary of this review will be helpful in the design of nickel-based catalysts and understanding the catalysis mechanism of nickel-based materials in alcohol fuel electrochemical reactions.展开更多
文摘Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.
基金financial support from the National Natural Science Foundation of China(22272148)。
文摘Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction(HER)but the effect of the crystal phase engineering of supports on their performance remains unclear.Here,the impact of the crystal phase of the support on the catalytic activity of Ru was probed by anchoring Ru nanoparticles onto precisely synthesized hexagonal(WO_(3)-H),orthorhombic(WO_(3)-O),and monoclinic(WO_(3)-M)supports followed by thorough evaluation for HER.Among them,WO_(3)-H demonstrated superior performance by providing enhanced Ru anchoring and uniform dispersion,maximizing active site availability.A critical finding is the small work function difference(ΔW_(F))between Ru and WO_(3)-H,which minimizes interfacial charge accumulation and facilitates efficient hydrogen spillover,thereby accelerating HER kinetics.In contrast,WO_(3)-O and WO_(3)-M exhibited largerΔW_(F)and less effective Ru dispersion,resulting in a larger hydrogen spillover barrier and suboptimal hydrogen adsorption/desorption dynamics.As a result,Ru/WO_(3)-H exhibited the best performance,achieving an overpotential of 43.8 mV at 10 mA cm^(-2)and a Tafel slope of 49.1 mV dec^(-1).This work highlights the critical role of the crystal phase in optimizing the intrinsic catalytic activity of catalysts,offering new insights for designing efficient HER catalysts.
基金supported in part by the National Natural Science Foundation of China under Grant 52177082in part by the Beijing Nova Program under Grant 20220484007.
文摘With the advent of the digital economy,there has been a rapid proliferation of small-scale Internet data centers(SIDCs).By leveraging their spatiotemporal load regulation potential through data workload balancing,aggregated SIDCs have emerged as promising demand response(DR)resources for future power distribution systems.This paper presents an innovative framework for assessing capacity value(CV)by aggregating SIDCs participating in DR programs(SIDC-DR).Initially,we delineate the concept of CV tailored for aggregated SIDC scenarios and establish a metric for the assessment.Considering the effects of the data load dynamics,equipment constraints,and user behavior,we developed a sophisticated DR model for aggregated SIDCs using a data network aggregation method.Unlike existing studies,the proposed model captures the uncertainties associated with end tenant decisions to opt into an SIDC-DR program by utilizing a novel uncertainty modeling approach called Z-number formulation.This approach accounts for both the uncertainty in user participation intentions and the reliability of basic information during the DR process,enabling high-resolution profiling of the SIDC-DR potential in the CV evaluation.Simulation results from numerical studies conducted on a modified IEEE-33 node distribution system confirmed the effectiveness of the proposed approach and highlighted the potential benefits of SIDC-DR utilization in the efficient operation of future power systems.
基金The work was supported by the National Natural Science Foundation of China(22272148,21972124)Chun Yin thanks the support of Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_3720).
文摘Interfacial electronic structure modulation of nickel-based electrocata-lysts is significant in boosting energy-conversion-relevant urea oxidation reaction(UOR).Herein,porous carbon nanofibers confined mixed Ni-based crystal phases of Ni_(2)P and NiF_(2) are developed via fluorination and phosphorization of Ni coated carbon nanofiber(Ni_(2)P/NiF_(2)/PCNF),which possess sufficient mesoporous and optimized Gibbs adsorption free energy by mixed phase-induced charge redistribution.This novel system further reduces the reaction energy barrier and improves the reaction activity by addressing the challenges of low intrinsic activity,difficulty in active site formation,and insufficient synergism.A considerably high current density of 254.29 mA cm^(-2) is reached at 1.54 V versus reversible hydrogen electrode on a glass carbon electrode,and the cell voltage requires 1.39 V to get 10 mA cm^(-2) in hydrogen generation,with very good stability,about 190 mV less than that of the traditional water electrolysis.The facile active phase formation and high charge transfer ability induced by asymmetric charge redistribution are found in the interface,where the urea molecules tend to bond with Ni atoms on the surface of heterojunction,and the rate-determining step is changed from CO_(2) desorption to the fourth H-atom deprotonation.The work reveals a novel catalyst system by interfacial charge redistribution induced by high bond polarity for energy-relevant catalysis reactions.
文摘实现绿色甲醇电解制氢需要高效的双功能催化剂。本文采用热处理结合乙二醇还原法成功制备了MoP-NC纳米球负载的超细Pt纳米粒子(平均粒径为2.53 nm)复合催化剂(Pt/MoP-NC)用于高效甲醇电解制氢。MoP-NC纳米球不仅能提高Pt纳米粒子的分散性并且增强Pt的抗中毒能力。电化学测试表明Pt/MoP-NC催化剂在酸性甲醇氧化反应(MOR)和析氢反应(HER)中具有较高的催化性能;其中,MOR的正向扫描峰值电流密度为90.7 m A·cm^(-2),是商业Pt/C催化剂的3.2倍,在10 mA·cm^(-2)的电流密度下,HER的过电位低至30 m V,与商业Pt/C接近。由Pt/MoP-NC||Pt/MoP-NC组装的两电极电解槽驱动10 mA·cm^(-2)的电流密度仅需要0.67 V的电压,比相同条件下电解水的电压低1.02 V,大大降低了能量输入。Pt/MoP-NC的高催化性能主要来源于Pt活性中心与相邻层状多孔球形结构的MoP-NC载体之间电子效应及配体效应引起的抗一氧化碳中毒能力的提升和含氧物种的容易生成。
基金supported by the National Natural Science Foundation of China (21972124, 22272148)the Priority Academic Program Development of Jiangsu Higher Education Institution。
文摘The strong metal-support interaction inducing combined effect plays a crucial role in the catalysis reaction. Herein, we revealed that the combined advantages of MoSe_(2), Ru, and hollow carbon spheres in the form of Ru nanoparticles(NPs) anchored on a two-dimensionally ordered MoSe_(2) nanosheet-embedded mesoporous hollow carbon spheres surface(Ru/MoSe_(2)@MHCS) for the largely boosted hydrogen evolution reaction(HER) performance. The combined advantages from the conductive support, oxyphilic MoSe_(2), and Ru active sites imparted a strong synergistic effect and charge redistribution in the Ru periphery which induced high catalytic activity, stability, and kinetics for HER. Specifically, the obtained Ru/MoSe_(2)@MHCS required a small overpotential of 25.5 and 38.4 mV to drive the kinetic current density of 10 mA cm^(-2)both in acid and alkaline media, respectively, which was comparable to that of the Pt/C catalyst. Experimental and theoretical results demonstrated that the charge transfer from MoSe_(2) to Ru NPs enriched the electronic density of Ru sites and thus facilitated hydrogen adsorption and water dissociation. The current work showed the significant interfacial engineering in Ru-based catalysts development and catalysis promotion effect understanding via the metal-support interaction.
基金supported by the National Natural Science Foundation of China (21972124, 22272148)the Priority Academic Program Development of Jiangsu Higher Education Institution。
文摘Bi-functional electrocatalysts for acid overall water splitting reactions are crucial but still challenging to the development of proton exchange membrane water electrolysis.Herein,an efficient bi-functional catalyst of Ir/MoS_(2) nanoflowers(Ir/MoS_(2) NFs) catalyst was reported for acidic water electrolysis which can be constructed by coupling three-dimensionally interconnected MoS_(2) NFs with ultrafine Ir nanoparticles.A more suitable adsorption ability for the H* and *OOH intermediates was revealed,where the Ir sites were proposed as the main active center and MoS_(2) promoted the charge relocation to electronically modify the interfacial structure.The significant interfacial charge redistribution between the MoS_(2) NFs and the Ir active sites synergistically induced excellent catalytic activity and stability for the water electrolysis reaction.Specifically,the catalyst required overpotentials of 270 and 35 mV to reach a kinetic current density of 10 mA cm^(-2)for OER and HER,respectively,loading on the glass carbon electrode,with high catalytic kinetics,stability,and catalytic efficiency.A two-electrode system constructed by Ir/MoS_(2) NFs drove 10 mA cm^(-2)at a cell voltage of 1.55 V,about 70 mV lower than that of the commercial Pt/C||IrO_(2) system.In addition,partial surface oxidation of Ir nanoparticles to generate high-valent Ir species was also found significant to accelerate OER.The enhanced catalytic performance was attributed to the strong metal-support interaction in the Ir/MoS_(2) NFs catalyst system that changed the electronic structure of Ir metal and promoted the synergistic catalytic effect between Ir and MoS_(2) NFs.The work presented a novel platform of Ir-catalyst for proton exchange membrane water electrolysis.
基金supported by the National Natural Science Foundation of China(Nos.22272148,22102105).
文摘Improving the catalytic efficiency and anti-poisoning ability of Pt-based catalysts is very critical in methanol electrolysis technology for high-purity hydrogen generation.Herein,the nitrogen-doped carbon polyhedrons-encapsulated Mop(MoP@NC)supported Pt nanoparticles were demonstrated to be effective for methanol electrolysis resulting from the combined advantages.The nitrogen-doped carbon polyhedrons not only greatly enhanced the conductivity but also effectively prevented the aggregation of MoP to offer Pt anchoring sites.The electronic structure modification of Pt from their interaction reduced the adsorption energy of co^(*),resulting in good cO-poisoning resistance and accelerated reaction kinetics.Specifically,Pt-MoP@NC exhibited the highest peak current density of 106.4 mA.cm^(-2) for methanol oxidation and a lower overpotential of 28 mV at 10 mA.cm^(-2) for hydrogen evolution.Energy-saving hydrogen production from methanol electrolysis was demonstrated in the two-electrode systems assembled by Pt-MoP@NC which required a low cell voltage of 0.65 V to reach a kinetic current density of 10 mA.cm-on the glass carbon system,about 1.02 V less than thatofwaterelectrolysis.
基金supported by the National Natural Science Foundation of China(21972124 and 22272148)。
文摘Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced by the variedly reported performance for the different Fe Ni structures.Herein,we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor.Driven by the complicated and compromised atmosphere,namely,the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe_(2)O_(3)and FeNi_(3)alloy,and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples.The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states,and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier.The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.
文摘化石燃料的大量消耗所带来的全球性挑战推动人们大力发展清洁和可持续的能源.氢能作为一种绿色、无污染的能源载体,是能源向绿色经济转换的关键,而利用可再生能源进行的电解水制氢被认为是实现绿色制氢的最佳选择.然而由于析氧反应(OER)的氧化电位(1.23 V)较高,动力学缓慢,实际水电解需要更多的能量输入.具有低氧化电位的甲醇辅助水电解(0.016 V)可以匹配可再生能源实现低能耗电解制氢,受到了广泛关注.开发高效的用于催化甲醇氧化(MOR)和析氢反应(HER)的双功能催化剂是实现这一愿景的前提.传统的Pt基催化剂容易受到阳极侧MOR过程中产生的CO中间体毒化,严重影响甲醇辅助水电解制氢的效率.为了提升Pt基催化剂的催化活性和稳定性,一种有效的策略是引入合适的功能组分来促进催化反应.例如,贵金属颗粒和亲氧化成分(如过渡金属氧化物和磷化物)之间的金属-载体相互作用可以有效提高Pt基催化剂的抗CO中毒能力.过渡金属硒化物由于其优良的金属性和亲氧性作为催化促进剂受到越来越多的关注.硒化钼(MoSe_(2))具有良好的稳定性和导电性并且其2H相中的不饱和边缘具有水活化和解离活性,同时其吸附H原子的吉布斯自由能(ΔGH^(*))接近于零.考虑到MoSe_(2)的高水活化/解离能力,本文成功制备了二维MoSe_(2)纳米片负载的Pt纳米粒子复合催化剂(Pt/MoSe_(2))用于高效甲醇电解制氢.密度泛函理论计算表明,亲氧组分MoSe_(2)显著优化了CO^(*)和H^(*)在Pt表面的吸附能,从而大大提高了甲醇辅助水电解的活性和稳定性.其中,Pt/MoSe_(2)的甲醇氧化峰值电流密度为67.8 m Acm^(-2),是商业Pt/C催化剂的2.5倍;在10 m A·cm^(-2)的电流密度下,HER的过电位低至32 m V.由Pt/MoSe_(2)|Pt/MoSe_(2)组装的两电极电解槽驱动10 m A·cm^(-2)的电流密度仅需要0.67 V的电压,与相同条件下的水电解相比节省了约1.09 V的电池电压,大大降低了能量输入.催化性能的提升可以归因于改善的电荷转移以及Pt与亲氧MoSe_(2)之间的金属-载体相互作用,该相互作用使得Pt从MoSe_(2)载体上得到了部分电子,增加了Pt周围的电子密度,使得邻近Pt的d带中心下移,从而通过削弱CO-Pt键进而增强了Pt位点的抗CO中毒能力.综上,本文对开发用于甲醇辅助水电解制氢的新型双功能催化剂具有借鉴意义.
文摘Efficient heterogeneous catalysts play a very important role in the value‐updated green hydrogen production from urea‐containing wastewater.Herein,NiSe_(2)/MoSe_(2)heterostructured catalyst with optimized interfacial electron redistribution and urea adsorption energies via a strong built‐in electric field was demonstrated effective for the urea‐assisted water splitting reactions.Efficient catalytic performance was found on NiSe_(2)/MoSe_(2)hybrid microsphere owing to the combined merits such as the unique structure features,the strong synergetic coupling effects,the increased active sites,and the high amount of intrinsic Ni^(3+)species.Excellent urea oxidation activity was found to drive 10 mA cm^(‒2)at the potential of 1.33 V when loaded on the glassy carbon electrode,and a cell voltage of 1.47 V was required in the NiSe_(2)/MoSe_(2)||Pt/C urea‐water electrolyzer to drive 10 mA cm^(‒2),about 220 mV less than that of water electrolysis,indicating a less energy consumption technique during the electrolysis.The spectroscopic and theoretical analysis revealed the effective synergy of the Ni-Se bond and Mo-Se bond that would be promising for efficient catalyst system construction.
基金supported by the National Natural Science Foundation of China(Nos.22302168 and 22272148).
文摘Methanol-assisted water electrolysis presents a promising yet challenging technique for electrochemical hydrogen production,as limited by the easy poisoning issue of Pt active sites.In this study,we successfully synthesized an efficient bifunctional catalyst composed of three-dimensional(3D)flower-like MoTe_(2) embedded nitrogen-doped carbon(NC)nanospheres,assembled by nanosheets,to support Pt nanoparticles(Pt-MoTe_(2)/NC)for methanol-assisted water electrolysis.This innovative Pt-MoTe_(2)/NC catalyst demonstrated superior catalytic performance targeting both hydrogen evolution reaction(HER)and methanol oxidation reaction(MOR)due to the strong metal-support interaction and the promotional effect of oxophilic molybdenum telluride.In situ infrared spectroscopy and CO stripping measurements revealed their excellent anti-poisoning ability.In particular,the onset potential of CO oxidation decreased by 130 mV relative to the standard Pt/C electrode.Theoretical calculations indicated the proper H*adsorption energy for HER and weakened CO adsorption energy for MOR in the optimized electronic structure.Therefore,the Pt-MoTe_(2)/NC electrode achieved the highest forward peak current density(76.6 mA·cm^(−2))for MOR,approximately 2.8-fold that of the commercial Pt/C,and only 34 mV was needed to deliver 10 mA·cm^(−2) for HER in acidic electrolyte.When employed as the bifunctional electrode in methanol electrolysis,Pt-MoTe_(2)/NC enabled efficient hydrogen generation with good stability,requiring merely 0.65 V to achieve 10 mA·cm^(−2),approximately 1090 mV less than traditional water electrolysis.This work presents an anti-poisoning catalyst in energy-saving hydrogen production from methanol electrolysis.
基金supported by the National Natural Science Foundation of China(22272148,22202172)financial support from the China Postdoctoral Science Foundation(2023M742947)support of the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Yangzhou University)(KYCX24_3720)。
文摘Developing heterojunction catalysts with diverse adsorption sites presents significant opportunities to enhance the performance of urea-assisted water electrolysis.Herein,we highlighted a NiTe/Mo_(6)Te_(8)heterojunction catalyst confined in carbon nanofiber with spontaneous charge redistribution driven by high valent metal,which promotes the adsorption and transformation of intermediates and greatly reduces the reaction energy barrier for urea oxidation.The heterojunction catalyst promotes the formation of Ni^(3+)active species and accelerates the fracture of the C-N bond by enhancing selective adsorption of-NH_(2)and C=O groups in binding urea molecules driven by the spontaneous formation of nucleophilic and electrophilic sites.The catalyst achieves a low kinetic current density of 10 mA cm^(-2)at 1.35 V with a cell voltage for urea electrolysis of just 1.47 V and good durability over 60 h.Density-functional theory and in-situ spectral observation reveal that the high valent Mo promoted the 3d orbit of Ni approaching the Fermi level by adjusting the electronic structure,which enhanced spontaneous urea dehydrogenation and reduced the energy barrier for^(*)COO desorption.This study highlights the effectiveness of modulating the interfacial electronic structure to improve energy conversion efficiency.
基金supported by the National Key Research and Development Program of China (2018YFB1502302)the National Natural Science Foundation of China (21972107, 21832004, and 21633008)+2 种基金the National Natural Science Foundation of Jiangsu Province (BK20191186)the Fundamental Research Funds for the Central UniversitiesLarge-scale Instrument and Equipment Sharing Foundation of Wuhan University。
文摘Improving the slow kinetics of alkaline hydrogen electrode reactions, involving hydrogen oxidation and evolution reactions(HOR/HER) is highly desirable for accelerating the commercialization of alkaline exchange membrane-based fuel cells(AEMFCs) and water electrolyzers(AEMWEs). However, fundamental understanding of the mechanism for HOR/HER catalysis under alkaline media is still debatable. Here we develop an amorphous tungsten oxide clusters modified iridium-tungsten nanocrystallines(Ir WOx)which exhibited by far the highest exchange current density and mass activity, about three times higher than the commercial Pt/C toward alkaline HOR/HER. Density functional theory(DFT) calculations reveal the WOxclusters act as a pivotal role to boost reversible hydrogen electrode reactions in alkaline condition but via different mechanisms, which are, hydrogen binding energy(HBE) mechanism for HOR and bifunctional mechanism for HER. This work is expected to promote our fundamental understanding about the alkaline HOR/HER catalysis and provide a new avenue for rational design of highly efficient electrocatalysts toward HOR/HER under alkaline electrolytes.
基金financially supported by the National Key Research and Development Program of China(no.2018YFB1502302)the National Natural Science Foundation of China(nos.21972107,21832004,21633008,and 51872115)+1 种基金the National Natural Science Foundation of Jiangsu Province(no.BK20191186)the National Natural Science Foundation of Hubei Province(no.2020CFA095).
文摘Exploring efficient and economical electrocatalysts and understanding the mechanism for alkaline hydrogen oxidation reaction(HOR)are crucial to facilitate the development of alkaline polymer electrolyte fuel cells(APEFCs).Herein,Ru_(2)P was synthesized and used as an anodic HOR electrocatalyst for APEFC,achieving a peak power density of 1.3 W cm^(−2),the highest value among Pt-free anode electrocatalysts reported under the same conditions.Fromthe density functional theory(DFT)calculations and experimental results,it was found that besides the optimized hydrogen binding energy,the enhanced adsorption strength of oxygenated species(OH*)and the reduced work function of Ru_(2)P contributed to the enhanced HOR performance.The normalized exchange current densities of Ru_(2)P/C were 0.37 mA cm_(ECSA)^(−2) and 0.27 mAμgRu^(−1),respectively,both approximately three times higher than those of Ru when conducted in the rotating disk electrode(RDE)system.Our work provides a new pathway for exploring highly active Pt-free HOR electrocatalysts and expanding the family of anodic electrocatalysts for APEFCs.
基金National Natural Science Foundation of China(21972124 and 22272148)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institution was also appreciated by the authors.
文摘Methanol as an important hydrogen-rich fuel has received increasing attention in energy storage and conversion techniques,and energy release can be realized in the methanol oxidation reaction(MOR)process.Note that highly efficient catalysts are still required to drive methanol oxidation,and the Ni-based catalysts have received intensive attention due to their facile active site generation based on the electrochemical-chemical oxidation mechanisms.In light of the significant advances made recently,herein,we reviewed the recent advances of Ni-based catalysts for methanol oxidation in the alkaline medium.The fundamental of methanol oxidation in the alkaline medium was first presented,and then the catalyst design principles including synergistic effect,electronic effect,defect construction,doping effect,as well as surface reconstruction were presented;and the advances of various Ni-based catalysts for MOR are summarized and discussed by combining with some typical examples.The problems and challenges were also concluded for the Ni-based catalyst fabrication,the performance evaluation,and their application.We believe that the summary of this review will be helpful in the design of nickel-based catalysts and understanding the catalysis mechanism of nickel-based materials in alcohol fuel electrochemical reactions.
