A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces...A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces of O2. Moreover, the immobilized cells increased both the evolution rate and the yield of hydrogen production. Batch experiments with a medium containing 10 g/L glucose demonstrated the yields of hydrogen production by the immobilized and free cells were 2.14 mol/mol glucose and 1.69 mol/mol glucose, respectively. In continuous cultures at medium retention time of 2.0 h, the yield and the evolution rate of hydrogen production by the immobilized cells were 2.31 mol/mol glucose and 1 435.4 ml/（L·h） respectively. However, at medium retention time of 6.0 h, the yield and the evolution rate of hydrogen production by free cells were only 1.75 mol/mol glucose and 362.9 ml/（L·h）, respectively.展开更多
Hydrogen,as a clean and sustainable energy source,is of great significance in addressing energy crises and environmental issues.Microorganisms such as Escherichia coli(E.coli)are commonly used to produce hydrogen due ...Hydrogen,as a clean and sustainable energy source,is of great significance in addressing energy crises and environmental issues.Microorganisms such as Escherichia coli(E.coli)are commonly used to produce hydrogen due to their high efficiency,wide choice of substrates,and fast growth rate.However,the hydrogenase in E.coli can only be activated to produce hydrogen under anaerobic conditions,which greatly limits its practical application as a hydrogen producing microorganism.Herein,we report a strategy to construct E.coli@ZIF-8 micro-nano reactors(MNRs).展开更多
The potential of a multiphase Al-Li alloy with the unreported Al1.08Li1.92 phase for use as a hydrolytic material to produce hydrogen was studied.This alloy enabled rapid hydrogen release in a wide temperature range w...The potential of a multiphase Al-Li alloy with the unreported Al1.08Li1.92 phase for use as a hydrolytic material to produce hydrogen was studied.This alloy enabled rapid hydrogen release in a wide temperature range with robust hydrogen yield.It could produce 1496 ml H2 per g within merely 0.5 min at 299 K and release 1076 ml H_(2)per g in 0.5 min even at a subzero temperature of 243 K.The hydrogen production kinetics were confirmed with a chemical step and could be well controlled by tailoring the solution components of water/ethanol mixtures.Furthermore,the alloy showed good air-resistance ability,indicating its suitability for safe handling and transport in practical applications.Our results confirmed the excellent hydrogen production achieved using this Al-based generation system.It might shed light on the progress of hydrogen production technologies for commercial use.展开更多
Electrocatalytic reduction of water is a promising route to produce hydrogen under mild conditions.High-index facet control is one of the most promising ways to achieve excellent catalytic activity for the hydrogen ev...Electrocatalytic reduction of water is a promising route to produce hydrogen under mild conditions.High-index facet control is one of the most promising ways to achieve excellent catalytic activity for the hydrogen evolution reaction(HER).However,the mechanism of the high-index facet enhancement remains unclear.Here,we combine in situ Raman spectroscopy and theoretical calculations to elucidate the mechanism of HER catalytic performance enhanced by high-index facets on Ti@TiO2 nanosheets.During the HER process,water molecules tend to adsorb to the high-index facet surface and then reduce to hydrogen.Our work lays the foundation for future exploration of the mechanism of electrocatalysis in transition-metal-based electrocatalysts by in situ Raman spectroscopy for applications in energy and environment-related issues.展开更多
Developing bifunctional electrocatalysts with high efficiency and prominent durability toward overall water splitting is a fascinating way to produce hydrogen for clean energy applications.In this work,partially oxidi...Developing bifunctional electrocatalysts with high efficiency and prominent durability toward overall water splitting is a fascinating way to produce hydrogen for clean energy applications.In this work,partially oxidized Ru nanoparticles integrated within electrospun carbon nanofibers(RuO_(2)/Ru-CNFs)are prepared via a convenient electrospinning-carbonization-oxidation process.展开更多
Water electrolysis is the most fascinating procedure for producing pure hydrogen owing to its flexibility and convenience.Platinum(Pt)is the most effective electrocatalyst for the hydrogen evolution reaction(HER)but i...Water electrolysis is the most fascinating procedure for producing pure hydrogen owing to its flexibility and convenience.Platinum(Pt)is the most effective electrocatalyst for the hydrogen evolution reaction(HER)but its high price and scarcity have greatly restricted its commercial application.Therefore,it is necessary to greatly increase the mass activity(MA)of Pt to meet practical applications.In the present study,an oxidized Pt atomic cluster-supported Au electrode(Pt_(AC)–O–Au)with an ultra-low loading was prepared by high vacuum magnetron sputtering combined with electrochemical anodic oxidation.The(Pt_(AC)–O–Au)-1 electrode has a very high mass activity(MA),reaching 49.2 A mg_(Pt)^(−1) at an overpotential of 50 mV,which is 41 times that of the 20 wt% Pt/C electrode and 20 times that of the 0.5 wt% Pt/C electrode.Even at such a low load,the(Pt_(AC)–O–Au)-1 electrode has excellent apparent activity and only needs an overpotential of 41 mV@10 mA cm^(−2),which is close to that of the 20 wt% Pt/C electrode(37 mV@10 mA cm^(−2)).Moreover,the(Pt_(AC)–O–Au)-1 electrode has an ultra-high specific activity(SA).The SA of(Pt_(AC)–O–Au)-1 is 12–18 times higher than that of the 0.5 wt%Pt/C electrode and 36–56 times higher than commercial Pt/C electrodes.More importantly,it was confirmed by the electrochemical analysis method(cyclic voltammetry and CO adsorption–stripping)and X-ray photoelectron spectroscopy(XPS)that the active site is the oxidized platinum(Pt–O–Au)on the surface of the electrode.Density functional theory(DFT)calculations have also elucidated that the absolute value ofΔG_(H*)(Pt)of Pt_(AC)–O–Au is close to that of Pt(111),indicating that its outstanding HER activity originates from its optimalΔG_(H*)(Pt)value.展开更多
Proton exchange membrane(PEM)electrolyzers are one of the most significant technologies for producing green hydrogen energy,in which nanostructured catalysts occupy an important role.At commercial densities,the nanoca...Proton exchange membrane(PEM)electrolyzers are one of the most significant technologies for producing green hydrogen energy,in which nanostructured catalysts occupy an important role.At commercial densities,the nanocatalysts on the cathode side in PEM electrolyzers often suffer from undesirable oxidation with the slight oxygen passing through the membrane.In this study,we designed a ternary Mo_(x)Pd_(y)Ni nanocatalyst supported on N-doped carbon(NC)from the pyrolysis of ZIF-8 toward the hydrogen evolution reaction(HER),while at the same time avoiding a loss of the activity toward the oxygen reduction reaction(ORR).Taking advantage of the charge redistribution among these elements,the representative Mo_(0.2)Pd_(3)Ni/NC exhibited a low overpotential(η_(10)=53 mV)toward HER with a low Tafel slope of 35.8 mV dec^(−1) in H_(2)SO_(4).In addition,Mo_(0.2)Pd_(3)Ni/NC also exhibited a half-wave potential of 0.90 V toward ORR with a mass activity of 0.78 A mg_(Pd)^(−1),which was twice that of Pt/C(0.38 A mg_(Pt)^(−1)).Microstructured analyses and density functional theory calculations revealed that the d-band center of Pd was downshifted by the synergistic effect between Ni and Mo,which weakened the binding energy of the intermediates with Pd,thus lowering the energy barrier toward HER and ORR.This strategy could significantly enhance the HER stability,which could be extended to the design of other bifunctional nanocatalysts for other reactions.展开更多
With a broad range of application prospects,hydrogen fuel cell technology is regarded as a clean and efficient energy conversion technology.Nevertheless,challenges exist in terms of the safe storage and transportation...With a broad range of application prospects,hydrogen fuel cell technology is regarded as a clean and efficient energy conversion technology.Nevertheless,challenges exist in terms of the safe storage and transportation of hydrogen.One proposed solution to this problem is the utilization of methanol on-line steam reforming technology for hydrogen production.In this paper,an integrated system for in-situ steam reforming of fuel coupled with proton exchange membrane fuel cells(PEMFC)power generation is proposed,and sensitivity analysis and exergy sensitivity analysis are conducted.Through the gradual utilization of waste heat and the integration of the system,fuel consumption is reduced and the power generation efficiency of the system is improved.Under the design operating conditions,the power generation efficiency and exergy efficiency of the system are achieved at 44.59%and 39.70%,respectively.This study presents a proven method for the efficient integration of fuel thermochemical conversion for hydrogen production with fuel cells for power generation,highlighting the advantages of complementary utilization of methanol steam reforming and PEMFC.展开更多
The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish ...The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.展开更多
Creating sophisticated and captivating electrocatalysts to produce hydrogen is extremely attractive but highly challenging with noble metal(NM)-free catalysts.The production of hydrogen fuel through seawater electroly...Creating sophisticated and captivating electrocatalysts to produce hydrogen is extremely attractive but highly challenging with noble metal(NM)-free catalysts.The production of hydrogen fuel through seawater electrolysis is an advancing sustainable alternative for mass utilization.In this work,we constructed CuS nanoparticles(NPs)on a thin 1T phase of WS_(2)/WO_(3)heterointerface,stabilized by ammonium ion(NH4+)intercalation(Cu@1T-N-W NSs).The developed NPs on a thin metallic sheets achieves high electrical conductivity and enhanced intrinsic activity in all of the edges and both basal planes.The Cu@1T-NW NS required only 121.8 mV and 158.2 mV to achieve 10 mA cm^(−2)in 1 M KOH and natural seawater+1 M KOH electrolytes,respectively.An operando EIS study reveals the complete electron-ion transportation and faster kinetics with various potentials.This work provides a unique path to design an NM-free catalyst with a stable metallic 1T phase for efficient hydrogen generation in alkaline and seawater electrolysis.展开更多
文摘A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces of O2. Moreover, the immobilized cells increased both the evolution rate and the yield of hydrogen production. Batch experiments with a medium containing 10 g/L glucose demonstrated the yields of hydrogen production by the immobilized and free cells were 2.14 mol/mol glucose and 1.69 mol/mol glucose, respectively. In continuous cultures at medium retention time of 2.0 h, the yield and the evolution rate of hydrogen production by the immobilized cells were 2.31 mol/mol glucose and 1 435.4 ml/（L·h） respectively. However, at medium retention time of 6.0 h, the yield and the evolution rate of hydrogen production by free cells were only 1.75 mol/mol glucose and 362.9 ml/（L·h）, respectively.
基金supported by the National Natural Science Foundation of China(22205100,22375091,and 21971114)the Jiangsu Provincial Funds for Natural Science Foundation(BK20200090).
文摘Hydrogen,as a clean and sustainable energy source,is of great significance in addressing energy crises and environmental issues.Microorganisms such as Escherichia coli(E.coli)are commonly used to produce hydrogen due to their high efficiency,wide choice of substrates,and fast growth rate.However,the hydrogenase in E.coli can only be activated to produce hydrogen under anaerobic conditions,which greatly limits its practical application as a hydrogen producing microorganism.Herein,we report a strategy to construct E.coli@ZIF-8 micro-nano reactors(MNRs).
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.NSFC51621001)the National Natural Science Foundation of China(No.51771075).
文摘The potential of a multiphase Al-Li alloy with the unreported Al1.08Li1.92 phase for use as a hydrolytic material to produce hydrogen was studied.This alloy enabled rapid hydrogen release in a wide temperature range with robust hydrogen yield.It could produce 1496 ml H2 per g within merely 0.5 min at 299 K and release 1076 ml H_(2)per g in 0.5 min even at a subzero temperature of 243 K.The hydrogen production kinetics were confirmed with a chemical step and could be well controlled by tailoring the solution components of water/ethanol mixtures.Furthermore,the alloy showed good air-resistance ability,indicating its suitability for safe handling and transport in practical applications.Our results confirmed the excellent hydrogen production achieved using this Al-based generation system.It might shed light on the progress of hydrogen production technologies for commercial use.
基金supported by the Key Research and Development Program of China(2019YFA0705700)the National Natural Science Foundation of China(51973244 and 21902188)+1 种基金the China Postdoctoral Science Foundation(2018M640847 and 2019T120764)the Fundamental Research Funds for the Central Universities(19lgpy15).
文摘Electrocatalytic reduction of water is a promising route to produce hydrogen under mild conditions.High-index facet control is one of the most promising ways to achieve excellent catalytic activity for the hydrogen evolution reaction(HER).However,the mechanism of the high-index facet enhancement remains unclear.Here,we combine in situ Raman spectroscopy and theoretical calculations to elucidate the mechanism of HER catalytic performance enhanced by high-index facets on Ti@TiO2 nanosheets.During the HER process,water molecules tend to adsorb to the high-index facet surface and then reduce to hydrogen.Our work lays the foundation for future exploration of the mechanism of electrocatalysis in transition-metal-based electrocatalysts by in situ Raman spectroscopy for applications in energy and environment-related issues.
基金supported by the National Natural Science Foundation of China(51973079 and 21875084)the Project of the Education Department of Jilin Province,China(JJKH20211047KJ).
文摘Developing bifunctional electrocatalysts with high efficiency and prominent durability toward overall water splitting is a fascinating way to produce hydrogen for clean energy applications.In this work,partially oxidized Ru nanoparticles integrated within electrospun carbon nanofibers(RuO_(2)/Ru-CNFs)are prepared via a convenient electrospinning-carbonization-oxidation process.
基金support from the Natural Science Foundation of Hubei province(2020CFB777).
文摘Water electrolysis is the most fascinating procedure for producing pure hydrogen owing to its flexibility and convenience.Platinum(Pt)is the most effective electrocatalyst for the hydrogen evolution reaction(HER)but its high price and scarcity have greatly restricted its commercial application.Therefore,it is necessary to greatly increase the mass activity(MA)of Pt to meet practical applications.In the present study,an oxidized Pt atomic cluster-supported Au electrode(Pt_(AC)–O–Au)with an ultra-low loading was prepared by high vacuum magnetron sputtering combined with electrochemical anodic oxidation.The(Pt_(AC)–O–Au)-1 electrode has a very high mass activity(MA),reaching 49.2 A mg_(Pt)^(−1) at an overpotential of 50 mV,which is 41 times that of the 20 wt% Pt/C electrode and 20 times that of the 0.5 wt% Pt/C electrode.Even at such a low load,the(Pt_(AC)–O–Au)-1 electrode has excellent apparent activity and only needs an overpotential of 41 mV@10 mA cm^(−2),which is close to that of the 20 wt% Pt/C electrode(37 mV@10 mA cm^(−2)).Moreover,the(Pt_(AC)–O–Au)-1 electrode has an ultra-high specific activity(SA).The SA of(Pt_(AC)–O–Au)-1 is 12–18 times higher than that of the 0.5 wt%Pt/C electrode and 36–56 times higher than commercial Pt/C electrodes.More importantly,it was confirmed by the electrochemical analysis method(cyclic voltammetry and CO adsorption–stripping)and X-ray photoelectron spectroscopy(XPS)that the active site is the oxidized platinum(Pt–O–Au)on the surface of the electrode.Density functional theory(DFT)calculations have also elucidated that the absolute value ofΔG_(H*)(Pt)of Pt_(AC)–O–Au is close to that of Pt(111),indicating that its outstanding HER activity originates from its optimalΔG_(H*)(Pt)value.
基金supported by Natural Science Foundation of Zhejiang Province(No.LZ22B060003)Major Scientific Project of Zhejiang Laboratory(No.2020MC0AD01).
文摘Proton exchange membrane(PEM)electrolyzers are one of the most significant technologies for producing green hydrogen energy,in which nanostructured catalysts occupy an important role.At commercial densities,the nanocatalysts on the cathode side in PEM electrolyzers often suffer from undesirable oxidation with the slight oxygen passing through the membrane.In this study,we designed a ternary Mo_(x)Pd_(y)Ni nanocatalyst supported on N-doped carbon(NC)from the pyrolysis of ZIF-8 toward the hydrogen evolution reaction(HER),while at the same time avoiding a loss of the activity toward the oxygen reduction reaction(ORR).Taking advantage of the charge redistribution among these elements,the representative Mo_(0.2)Pd_(3)Ni/NC exhibited a low overpotential(η_(10)=53 mV)toward HER with a low Tafel slope of 35.8 mV dec^(−1) in H_(2)SO_(4).In addition,Mo_(0.2)Pd_(3)Ni/NC also exhibited a half-wave potential of 0.90 V toward ORR with a mass activity of 0.78 A mg_(Pd)^(−1),which was twice that of Pt/C(0.38 A mg_(Pt)^(−1)).Microstructured analyses and density functional theory calculations revealed that the d-band center of Pd was downshifted by the synergistic effect between Ni and Mo,which weakened the binding energy of the intermediates with Pd,thus lowering the energy barrier toward HER and ORR.This strategy could significantly enhance the HER stability,which could be extended to the design of other bifunctional nanocatalysts for other reactions.
基金supported by the National Key R&D Program of China(2021YFF0500701)Youth Innovation Promotion Association CAS(2021141)。
文摘With a broad range of application prospects,hydrogen fuel cell technology is regarded as a clean and efficient energy conversion technology.Nevertheless,challenges exist in terms of the safe storage and transportation of hydrogen.One proposed solution to this problem is the utilization of methanol on-line steam reforming technology for hydrogen production.In this paper,an integrated system for in-situ steam reforming of fuel coupled with proton exchange membrane fuel cells(PEMFC)power generation is proposed,and sensitivity analysis and exergy sensitivity analysis are conducted.Through the gradual utilization of waste heat and the integration of the system,fuel consumption is reduced and the power generation efficiency of the system is improved.Under the design operating conditions,the power generation efficiency and exergy efficiency of the system are achieved at 44.59%and 39.70%,respectively.This study presents a proven method for the efficient integration of fuel thermochemical conversion for hydrogen production with fuel cells for power generation,highlighting the advantages of complementary utilization of methanol steam reforming and PEMFC.
基金Science and Technology Department of Sichuan Province,Grant/Award Number:2022YFH0094National Natural Science Foundation of China,Grant/Award Numbers:51973141,52033005,U21A2090。
文摘The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.
基金supported by“Regional Innovation Strategy(RIS)”through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(2024RIS-008)supported by“HRD Program for Industrial Innovation(Carbon Composite Professional Human Resources Training Program)”grant funded by the Korea Government(MOTIE),(P0017002,2024)supported by“Regional Integrated Hydrogen Industry Human Resource Development(Jeonbuk National University)Program”grant funded by the Ministry of Trade,Industry and Energy(H2 Korea).
文摘Creating sophisticated and captivating electrocatalysts to produce hydrogen is extremely attractive but highly challenging with noble metal(NM)-free catalysts.The production of hydrogen fuel through seawater electrolysis is an advancing sustainable alternative for mass utilization.In this work,we constructed CuS nanoparticles(NPs)on a thin 1T phase of WS_(2)/WO_(3)heterointerface,stabilized by ammonium ion(NH4+)intercalation(Cu@1T-N-W NSs).The developed NPs on a thin metallic sheets achieves high electrical conductivity and enhanced intrinsic activity in all of the edges and both basal planes.The Cu@1T-NW NS required only 121.8 mV and 158.2 mV to achieve 10 mA cm^(−2)in 1 M KOH and natural seawater+1 M KOH electrolytes,respectively.An operando EIS study reveals the complete electron-ion transportation and faster kinetics with various potentials.This work provides a unique path to design an NM-free catalyst with a stable metallic 1T phase for efficient hydrogen generation in alkaline and seawater electrolysis.
