Based on experimental results in which VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at%V nanocomposite, a VH/MgH2 in- terface is designed and constituted in this work. A first-princ...Based on experimental results in which VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at%V nanocomposite, a VH/MgH2 in- terface is designed and constituted in this work. A first-principles plane-wave pseudopo- tential method based on Density Functional Theory (DFT) has been used to investigate the vanadium alloying effects on the dehydrogenating properties of magnesium hydride, i.e., MgH2. A low absolute value of the negative heat of formation of VH/MgH2 interface compared with that of MgH2 indicates that vanadium hydrides befit to improve the dehydrogenating properties of MgH2. Based on the analysis of the density of states (DOS) and the total valence electron density distribution of MgH2 before and after V alloying, it was found that the improvement of the dehydrogenating properties of MgH2 caused by V alloying originates from the increasing of the valence electrons at Fermi level (EF) and the decreasing of the HOMO-LUMO gap ( Δ E H ?L) after V alloying. The catalysis effect of V on dehydrogenating kinetics of MgH2 may attribute to a stronger bonding between V and H atoms than that between Mg and H atoms, which leads to nucleation of the α-Mg at the VH/MgH2 interface in the MgH2-V systems easier than that in pure MgH2 phase.展开更多
Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using iso...Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.展开更多
Acceptorless dehydrogenative coupling of pyridinemethanol with ketones is one of the most reliable methodologies to access functionalized 1,8-naphthyridine derivatives.However,it is challenging to develop environmenta...Acceptorless dehydrogenative coupling of pyridinemethanol with ketones is one of the most reliable methodologies to access functionalized 1,8-naphthyridine derivatives.However,it is challenging to develop environmentally friendly catalytic systems,especially in constructing efficient and recyclable catalysts under water or solvent-free conditions.Here,we designed two novel coordination polymers Cd-CPs and Fe-CPs to investigate their catalytic performance in water.Gratifyingly,it was observed that Cd-CPs as a multifunctional catalyst was successfully applied to establish a universal pathway for direct fabrication of 1,8-naphthyridine derivatives under water conditions,while it was effective for the synthesis of1,3,5-triazines through acceptorless dehydrogenative coupling strategies.The features of broad substrate,high atom efficiency,and good catalyst reusability highlight the feasibility of this transformation.In additional,we demonstrated the spindle-like structures Fe-P,derived from the Fe-CPs via phosphorylation,which can be used as an efficient electrocatalyst for oxygen evolution reaction with good stability.This work provides two highly efficient non-noble metal catalysts for functionalized 1,8-naphthyridine derivatives production and oxygen evolution reaction,and opens a new avenue to further fabricate diverse metal catalysts with high catalytic performance in water.展开更多
The efficient storage and release of H_(2)are pivotal for the advancement of hydrogen energy technologies.Cyclohexane,as a promising liquid organic hydrogen carrier(LOHC),provides a safe and practical solution for H_(...The efficient storage and release of H_(2)are pivotal for the advancement of hydrogen energy technologies.Cyclohexane,as a promising liquid organic hydrogen carrier(LOHC),provides a safe and practical solution for H_(2)storage.However,the performance limitations of dehydrogenation catalysts have hindered the rapid development of LOHC technology.In this study,we successfully developed boron-modified Pt/ZrO_(2)catalysts,which exhibit exceptional catalytic performance in cyclohexane dehydrogenation.The optimal boron content is determined to be 0.5 wt.%,with the Pt/0.5B–ZrO_(2)catalyst achieving high turnover frequency(TOF)of 10,627.3 mol_(H_(2))·mol_(Pt)^(−1)·h^(−1)and benzene selectivity of 99%at 295°C.The catalyst also demonstrates H_(2)evolution rate of 908 mmol·g_(Pt)^(−1)·min^(−1)and low deactivation rate of 0.0043 h^(−1).Remarkably,the catalyst displays outstanding stability and regeneration performance,maintaining its activity without significant loss during a 60-h dehydrogenation reaction and retaining a cyclohexane conversion of 77.2%after 10 consecutive cycles.Comprehensive characterization techniques,including XPS,CO-FTIR,NH_(3)-TPD,H_(2)-TPD,Benzene-TPD,and Py-IR,reveals that boron modification reduces the electron density of Pt,generating abundant electron-deficient Pt atoms.These electron-deficient Pt atoms enhance H_(2)adsorption and accelerate benzene desorption,effectively preventing coke formation from deep benzene dehydrogenation,which is responsible for the high catalytic performance of the Pt/0.5B–ZrO_(2)catalyst.These findings offer a valuable strategy for optimizing dehydrogenation catalysts in LOHC technologies,addressing a critical bottleneck in the development of this essential energy storage solution.展开更多
Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitti...Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitting reveal two mechanisms:one shows a maximum rate at the early stage,such as V and Cr;the other needs a temperature-sensitive preparation time for its maximum rate,such as Ni.The combina-tion of two catalyst components demonstrates the best kinetics:V and Cr boost the initial dehydrogena-tion,and Ni benefits the further hydrogen transfer which alleviates the rate of decay.This work provides guidelines for the design of multi-element doped catalysts for MgH_(2) dehydrogenation.展开更多
Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron...Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.展开更多
A first-principles study was reported based on density functional theory of hydrogen vacancy,metal dopants,metal dopant-vacancy complex in LiBH4,a promising material for hydrogen storage.The formation of H vacancy and...A first-principles study was reported based on density functional theory of hydrogen vacancy,metal dopants,metal dopant-vacancy complex in LiBH4,a promising material for hydrogen storage.The formation of H vacancy and metal doping in LiBH4 is difficult,and their concentrations are low.The presence of one kind of defect is helpful to the formation of other kind of defect.Based on the analysis of electronic structure,the improvement of the dehydrogenating kinetics of LiBH4 by metal catalysts is due to the weaker bonding of B—H and the new metal-like system,which makes H atom diffuse easily;H vacancy accounts for a trace amount of BH3 release during the decomposing process of LiBH4;metal dopant weakens the strength of B—H bonds,which reduces the dehydriding temperature of LiBH4.The roles of metal and vacancy in the metal dopant-vacancy complex can be added in LiBH4 system.展开更多
The dehydrogenation of alkanes has emerged as a vital complementary process to address the increasing global demand for olefins.A key challenge remains in the construction of novel active centers that offer superior a...The dehydrogenation of alkanes has emerged as a vital complementary process to address the increasing global demand for olefins.A key challenge remains in the construction of novel active centers that offer superior activity,stability,and cost-effectiveness.Herein,tricoordinated cobalt atoms were successfully fabricated through an in-situ ligand-protected synthesis by introducing tungsten atoms into zeolite frameworks.These unsaturated Co species efficiently activate C-H bonds while suppressing C-C bond cleavage,resulting in exceptional catalytic activity and olefin selectivity in both propane and ethane dehydrogenation reactions.The optimized Co_(0.2%)@0.01W-S-1 catalyst demonstrated an impressive propylene formation rate of 15.2 molC_(3H6)gcC h^(-1)at 823 K and an ethylene formation rate of 240.3mol_(C2H4)g_(Co)^(-1)h^(-1)at 913 K,with propylene and ethylene selectivities of 99.0%and 97.5%,respectively.These results not only significantly surpass conventional tetracoordinated Co catalysts but also rival some Pt-based catalysts under similar conditions.Importantly,the catalyst exhibited excellent stability in dehydrogenation reactions,with no significant loss in catalytic activity after five consecutive regeneration cycles.This work offers valuable insights into the design of zeolite-supported non-precious metal catalysts with high activity and durability for efficient alkane dehydrogenation.展开更多
Propylene,a pivotal chemical feedstock,is extensively used in synthesizing high-value derivatives such as polypropylene and acrylonitrile[1].Although propylene is predominantly produced via naphtha cracking,a persiste...Propylene,a pivotal chemical feedstock,is extensively used in synthesizing high-value derivatives such as polypropylene and acrylonitrile[1].Although propylene is predominantly produced via naphtha cracking,a persistent supply-demand gap exists[2].Non-oil routes,such as propane dehydrogenation(PDH),are increasingly attractive,particularly with the availability of shale gas[3].Modern non-oxidative PDH heavily relies on Pt nanoparticle catalysts promoted with SnOx(e.g.,PtSn/Al2O3 used in Honeywell UOP's Oleflex process)[4].However,these systems suffer from inherent limitations:high Pt costs,coke formation via deep dehydrogenation,and sintering during regeneration-necessitating environmentally detrimental oxychlorination treatments to restore activity[5].展开更多
Non-oxidative dehydrogenation of propane(PDH)is an important route for large-scale on purpose propene production.Although cobalt-based catalysts are promising alternatives to currently used platinum-or chromium oxide-...Non-oxidative dehydrogenation of propane(PDH)is an important route for large-scale on purpose propene production.Although cobalt-based catalysts are promising alternatives to currently used platinum-or chromium oxide-based catalysts,their further developments are hindered by the uncertainties related to the kind of the active sites involved in the desired and side reactions.To contribute to closing such a gap,we systematically investigate the role of oxidized CoO_(x) and metallic Co0 species in the PDH reaction over catalysts based in Silicalite-1 with supported CoO_(x) species differing in their redox properties.C_(3)H_(8) pulse experiments with sub-millisecond and second resolution at pulse sizes of about 13 and 2200 nmol,respectively,combined with in-depth catalyst characterization and PDH tests at different propane conversions enabled us to understand how the reaction-induced reduction of CoO_(x) affects product selectivity.Propane readily reacts with CoO_(x) to yield propene,carbon oxides and water.The formed Co0 species show high activity to coking and cracking reactions.However,if the size of such species is below 2 nm,these undesired reactions are significantly hindered due to the coverage of the active sites by carbon-containing species.The remaining uncovered surface Co0 sites selectively dehydrogenate propane to propene.The best-performing catalyst showed higher activity than a commercial-like K-CrOx/Al_(2)O_(3) and operated durable in a series of 10 dehydrogenation/regeneration cycles under industrial relevant conditions.The space time yield of propene formation of 0.97 kg·h^(-1)·kgcat^(-1) was achieved at 550℃,52%equilibrium propane conversion and 95% propene selectivity.展开更多
Modifying the electronic density of states and the synergistic effect of the active centers by introducing a second metal present an efficient strategy to tune physi/chemi-sorption,probably lead to improving catalytic...Modifying the electronic density of states and the synergistic effect of the active centers by introducing a second metal present an efficient strategy to tune physi/chemi-sorption,probably lead to improving catalytic performances.Herein,bimetallic Ni_(3)Mo/Al_(2)O_(3)catalyst was demonstrated and exhibited over 5 times more active than Pt/Al_(2)O_(3)toward the ethane dehydrogenation(EDH)as well as 2-10 times activity enhancement compared with their monometallic Ni and Mo counterparts and other Ni-based bimetallic nanoparticles.Kinetic studies revealed that the activation energy over Ni_(3)Mo/Al_(2)O_(3)(111 kJ mol^(-1))was much lower than that of Ni(157 kJ mol^(-1))and Mo(171 kJ·mol^(-1)).DFT calculations showed ethane was adsorbed on the Ni or Mo surface in a more parallel configuration,whereas over Ni_(3)Mo it adopted an inclined configuration.This change promoted ethane adsorption and pre-activation of the C-H bond,thereby benefiting the ethane dehydrogenation process on the Ni_(3)Mo surface.展开更多
The bicarbonate-formate(HCO_(3)−–HCO_(2)−)interconversion provides a promising cycle for a conveniently accessible hydrogen storage system via reversible dehydrogenation and hydrogenation processes.Existing catalytic...The bicarbonate-formate(HCO_(3)−–HCO_(2)−)interconversion provides a promising cycle for a conveniently accessible hydrogen storage system via reversible dehydrogenation and hydrogenation processes.Existing catalytic systems often use organic solvents,tedious optimization as well as manipulation of pH values,solvent,pressure and various additives.Herein,we present an operational,robust,safe and cost-effective catalytic system for hydrogen storage and liberation.We have established a unique catalytic system with two different solid organometallic assemblies(NHC-Ru and NHC-Ir)that facilitate the reversible transformation between sodium formate and bicarbonate in aqueous solutions collaboratively and efficiently.Notably,the NHC-Ru catalyst is privileged for the hydrogenation of sodium bicarbonate,whereas the NHC-Ir component enables the dehydrogenation of sodium formate,all in a single reaction vessel.What sets this system apart is its simplicity.The H_(2)discharging and recharging is simply regulated by heating the mixture with or without H_(2).Remarkably,this process requires no extra additives or supplementary treatments.Moreover,the reversible hydrogen storage system is durable and can be reused for over 30 cycles without a discernible decline in activity and selectivity.The strategic paradigm in this study shows significant practical potential in hydrogen fuel cell applications.展开更多
Photocatalytic water splitting using natural solar light is considered as a sustainable approach to generate H_(2) and O_(2).While H_(2) has high market value,the by-product of water splitting,oxygen,is less valuable....Photocatalytic water splitting using natural solar light is considered as a sustainable approach to generate H_(2) and O_(2).While H_(2) has high market value,the by-product of water splitting,oxygen,is less valuable.To make H_(2) produced by means of photocatalysis more economically competitive to that generated from methane,its generation is studied together with synthesis of organic compounds that have higher market value.This review summarizes and analyzes critically dehydrogenation reactions that were developed since 1980s.Photocatalytic dehydrogenation reactions are classified and the results are collected in the online database.Performance of homogeneous and heterogenous photocatalysts in dehydrogenation reactions,such as yield rates of organic products on analytical and preparative scales,and quantum efficiencies are compared.Current limitations of the existing methods and photocatalytic systems are identified and directions for the future developments are outlined.展开更多
The single-atom M-N-C(M typically being Co or Fe)is a prominent material with exceptional reactivity in areas of catalysis for sustainable energy.However,the formation of metal nanoparticles in M-N-C materials is coup...The single-atom M-N-C(M typically being Co or Fe)is a prominent material with exceptional reactivity in areas of catalysis for sustainable energy.However,the formation of metal nanoparticles in M-N-C materials is coupled with hightemperature calcination conditions,limiting the density of M-Nx active sites and thus restricting the catalytic performance of such catalysts.Herein,we describe an effective decoupling strategy to construct high-density M-Nx active sites by generating polyfurfuryl alcohol in the MOF precursor,effectively preventing the formation of metal nanoparticles even with up to 6.377%cobalt loading.This catalyst showed a high H_(2) production rate of 778mLgcat^(−1) h^(−1) when used in the dehydrogenation reaction of formic acid.In addition to the high density of the active site,a curved carbon surface in the structure is also thought to be the reason for the high performance of the catalyst.展开更多
Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally ...Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally friendly and cost-effective alternatives.In this study,we developed a facile impregnation method to fabricate unsaturated Co single-atoms with a tricoordinated Co_(1)O_(3)H_(x) structure by regulating silanol nests in purely siliceous Beta zeolites.Detailed PDH catalytic tests and characterizations revealed a positive correlation between the presence of silanol nests and enhanced catalytic activity.Additionally,the unsaturated Co single-atoms exhibited a carbon deposition rate more than an order of magnitude slower than that of Co nanoparticles.Notably,the optimized Co_(0.3%)/deAl-meso-Beta catalyst achieved a record-high propylene formation rate of 21.2 mmol_(C3H6) g_(cat)^(-1) h^(-1),with an exceptional propylene selectivity of 99.1%at 550℃.Moreover,the Co_(0.3%)/deAl-meso-Beta catalyst demonstrated excellent stability,with negligible deactivation after 5 consecutive regeneration cycles.This study emphasizes the pivotal role of silanol nests of zeolites in stabilizing and modulating the coordination environment of metallic active sites,providing valuable insights for the design of high-activity,high-stability,and low-cost PDH catalysts.展开更多
Recent studies have revealed the extraordinary performance of zirconium oxide in propane dehydrogenation,which is attributed to the excellent reactivity of the coordinatively unsaturated zirconium sites(Zr_(cus))aroun...Recent studies have revealed the extraordinary performance of zirconium oxide in propane dehydrogenation,which is attributed to the excellent reactivity of the coordinatively unsaturated zirconium sites(Zr_(cus))around the oxygen vacancies.The origin of the enhanced catalytic activity of ZrO_(2)with defective tetrahedral Zr sites was examined by direct comparison with its pristine counterpart in the current study.Electronic-structure analysis revealed that electrons from oxygen removal were localized within vacancies on the defective surface,which directly attacked the C-H bond in propane.The involvement of localized electrons activates the C-H bond via back-donation to the antibonding orbital on the defective surface;conversely,charge is transferred from propane to the pristine surfaces.The barrier for the first C-H bond activation is clearly significantly reduced on the defective surfaces compared to that on the pristine surfaces,which verifies the superior activity of Zr_(cus).Notably,however,the desorption of both propene and hydrogen molecules from Zr_(cus)is more difficult due to strong binding.The calculated turnover frequency(TOF)for propene formation demonstrates that the pristine surfaces exhibit better catalytic performance at lower temperatures,whereas the defective surfaces have a larger TOF at high temperatures.However,the rate-determining step and reaction order on the defective surface differ from those on the pristine surface,which corroborates that the catalysts follow different mechanisms.A further optimization strategy was proposed to address the remaining bottlenecks in propane dehydrogenation on zirconium oxide.展开更多
Supported metal oxide catalysts have garnered significantattention in oxidative dehydrogenation(ODH)due to their tunable metal-support interactions.The pentacoordinate Al^(3+)(Al_(V)^(3+))in γ-Al_(2)O_(3)supports pla...Supported metal oxide catalysts have garnered significantattention in oxidative dehydrogenation(ODH)due to their tunable metal-support interactions.The pentacoordinate Al^(3+)(Al_(V)^(3+))in γ-Al_(2)O_(3)supports plays a pivotal role in modulating metal-support interaction.This study investigates oxalic acid(OA)pretreatment as a defect engineering strategy to enhance the catalytic performance of CeO_(2)/γ-Al_(2)O_(3)in cyclohexane ODH.Through integrated characterization(XRD,27Al MAS NMR,H_(2)-TPR,TPRO,MS,XPS)and catalytic testing,we demonstrate that optimal OA treatment(1:10 ratio)eliminates 100%of surface Al_(V)^(3+)defects while enhancing CeO_(2)crystallinity and interfacial oxygen mobility.The removal of Al_(V)^(3+)species restructures metal-support interaction,accelerating interfacial oxygen mobility.In oxidation dehydrogenation of cyclohexane,the modified CeO_(2)/γ-Al_(2)O_(3)achieves 29%of cyclohexane conversion with stable selectivity of 49%cyclohexene.These findingsprovide an initial framework for designing redox-active catalysts via targeted support modificationin CeO_(2)/γ-Al_(2)O_(3)systems,emphasizing the relationship between metal-support interaction and oxygen mobility.展开更多
The development of formic acid dehydrogenation materials with high activity and low cost is key to realizing hydrogen energy utilization.Herein,we describe a specific low-loading strategy to construct a high-activity ...The development of formic acid dehydrogenation materials with high activity and low cost is key to realizing hydrogen energy utilization.Herein,we describe a specific low-loading strategy to construct a high-activity Co atom site catalyst for this reaction.Under optimal conditions,the formic acid dehydrogenation performance of Co─Fe dual-atom catalyst(turnover frequency of 2,446.8 h^(−1),hydrogen production rate of 1,015,306.1 mL gCo^(−1)h^(−1))was 300 times greater than that of commercial 5%Pd/C.High-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectra,combined with theoretical calculations,confirm that the presence of different active sites(Co single-atom,Co-Co dual-atom,Co─Fe dual-atom)in catalysts is the key factor affecting their catalytic activity.These findings provide a strong scientific basis for the development of single-atom and dual-atom catalysts.展开更多
In response to the increasing demand of ethylene,electrochemical ethane nonoxidative dehydrogenation(EENDH)to ethylene by protonic ceramic electrolysis cells(PCECs)is developed.However,existing anode materials exhibit...In response to the increasing demand of ethylene,electrochemical ethane nonoxidative dehydrogenation(EENDH)to ethylene by protonic ceramic electrolysis cells(PCECs)is developed.However,existing anode materials exhibit poor proton conductivity and limited catalytic activity.Herein,a novel Sr_(1.95)Fe_(1.4)Co_(0.1)Mo_(0.4)Zr_(0.1)O_(6-δ)(SFCMZ)anode is prepared as PCECs anode for EENDH.Zr doping increases the oxygen vacancies and enhances the proton conductivity of SFCMZ.Moreover,an alloy-oxide heterostructure(Co Fe@SFCMZ)is formed through in-situ exsolution of Co Fe alloy nanoparticles under reduction conditions,generating abundant oxygen vacancies and improving its catalytic activity.Co Fe@SFCMZ cell achieves an electrolysis current density of 0.87 A/cm^(2) at 700℃ under 1.6 V,with an ethane conversion rate of 34.22%and corresponding ethylene selectivity of 93.4%.These results demonstrate that Co Fe@SFCMZ anode exhibits excellent electrocatalytic activity,suggesting promising applications for EENDH.展开更多
Owing to high thermal stability and large reaction enthalpy,Mg H_(2) has high reaction temperatures and sluggish reaction kinetics in the dehydrogenation process,which consumes lots of energy.To achieve hydrogen relea...Owing to high thermal stability and large reaction enthalpy,Mg H_(2) has high reaction temperatures and sluggish reaction kinetics in the dehydrogenation process,which consumes lots of energy.To achieve hydrogen release with low energy consumption,accelerated reaction rate,and high heating uniformity,this paper proposes a novel method of graphite responsive microwave-assisted thermal management with NaTiO_(x)H catalyst.A multi-physics model of the 5 wt%NaTiO_(x)H catalyzed Mg H_(2) reactor integrated with a microwave generator is developed to investigate the reaction,heat and mass transfer process of hydrogen release.It is found that the graphite responsive microwave heating method could improve the temperature uniformity of reaction bed,reduce the energy consumption by at least 10.71%and save the hydrogen release time by 53.49% compared with the traditional electric heating method.Moreover,the hydrogen desorption thermodynamics could be improved with the increase of microwave power.The hydrogen release time is shortened by 19.55%with the increase of 20 W microwave power.Meanwhile,it is also concluded that the microwave excitation frequency of 2.1 GHz and the graphite content of 2 wt%have better heating performance.Therefore,it can be verified that the graphite responsive microwave heating helps to low-energy and accelerated hydrogen release from MgH_(2) hydrogen storage reactor.展开更多
文摘Based on experimental results in which VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at%V nanocomposite, a VH/MgH2 in- terface is designed and constituted in this work. A first-principles plane-wave pseudopo- tential method based on Density Functional Theory (DFT) has been used to investigate the vanadium alloying effects on the dehydrogenating properties of magnesium hydride, i.e., MgH2. A low absolute value of the negative heat of formation of VH/MgH2 interface compared with that of MgH2 indicates that vanadium hydrides befit to improve the dehydrogenating properties of MgH2. Based on the analysis of the density of states (DOS) and the total valence electron density distribution of MgH2 before and after V alloying, it was found that the improvement of the dehydrogenating properties of MgH2 caused by V alloying originates from the increasing of the valence electrons at Fermi level (EF) and the decreasing of the HOMO-LUMO gap ( Δ E H ?L) after V alloying. The catalysis effect of V on dehydrogenating kinetics of MgH2 may attribute to a stronger bonding between V and H atoms than that between Mg and H atoms, which leads to nucleation of the α-Mg at the VH/MgH2 interface in the MgH2-V systems easier than that in pure MgH2 phase.
基金supported by the National Natural Science Foundation of China(Nos.22271007,W2431014)Peking University Shenzhen Graduate School+2 种基金State Key Laboratory of Chemical OncogenomicsShenzhen Key Laboratory of Chemical GenomicsShenzhen Bay Laboratory.
文摘Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.
基金financial support of this work by the National Natural Science Foundation of China(No.21861039)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_2530)the Fundamental Research Funds for the Central Universities。
文摘Acceptorless dehydrogenative coupling of pyridinemethanol with ketones is one of the most reliable methodologies to access functionalized 1,8-naphthyridine derivatives.However,it is challenging to develop environmentally friendly catalytic systems,especially in constructing efficient and recyclable catalysts under water or solvent-free conditions.Here,we designed two novel coordination polymers Cd-CPs and Fe-CPs to investigate their catalytic performance in water.Gratifyingly,it was observed that Cd-CPs as a multifunctional catalyst was successfully applied to establish a universal pathway for direct fabrication of 1,8-naphthyridine derivatives under water conditions,while it was effective for the synthesis of1,3,5-triazines through acceptorless dehydrogenative coupling strategies.The features of broad substrate,high atom efficiency,and good catalyst reusability highlight the feasibility of this transformation.In additional,we demonstrated the spindle-like structures Fe-P,derived from the Fe-CPs via phosphorylation,which can be used as an efficient electrocatalyst for oxygen evolution reaction with good stability.This work provides two highly efficient non-noble metal catalysts for functionalized 1,8-naphthyridine derivatives production and oxygen evolution reaction,and opens a new avenue to further fabricate diverse metal catalysts with high catalytic performance in water.
基金supported by National Natural Science Foundation of China(22478076,U25B6005)National Key R&D Program of China(2021YFA1500302)+1 种基金Industrial Joint Fund of Qingyuan Innovation Laboratory(00422001)111 Project(D17005).
文摘The efficient storage and release of H_(2)are pivotal for the advancement of hydrogen energy technologies.Cyclohexane,as a promising liquid organic hydrogen carrier(LOHC),provides a safe and practical solution for H_(2)storage.However,the performance limitations of dehydrogenation catalysts have hindered the rapid development of LOHC technology.In this study,we successfully developed boron-modified Pt/ZrO_(2)catalysts,which exhibit exceptional catalytic performance in cyclohexane dehydrogenation.The optimal boron content is determined to be 0.5 wt.%,with the Pt/0.5B–ZrO_(2)catalyst achieving high turnover frequency(TOF)of 10,627.3 mol_(H_(2))·mol_(Pt)^(−1)·h^(−1)and benzene selectivity of 99%at 295°C.The catalyst also demonstrates H_(2)evolution rate of 908 mmol·g_(Pt)^(−1)·min^(−1)and low deactivation rate of 0.0043 h^(−1).Remarkably,the catalyst displays outstanding stability and regeneration performance,maintaining its activity without significant loss during a 60-h dehydrogenation reaction and retaining a cyclohexane conversion of 77.2%after 10 consecutive cycles.Comprehensive characterization techniques,including XPS,CO-FTIR,NH_(3)-TPD,H_(2)-TPD,Benzene-TPD,and Py-IR,reveals that boron modification reduces the electron density of Pt,generating abundant electron-deficient Pt atoms.These electron-deficient Pt atoms enhance H_(2)adsorption and accelerate benzene desorption,effectively preventing coke formation from deep benzene dehydrogenation,which is responsible for the high catalytic performance of the Pt/0.5B–ZrO_(2)catalyst.These findings offer a valuable strategy for optimizing dehydrogenation catalysts in LOHC technologies,addressing a critical bottleneck in the development of this essential energy storage solution.
基金Yijing Wang acknowledges the funding support of the National Key Research and Development Program of China(No.2021YFB4000604)the National Natural Science Foundation of China(No.52271220)+6 种基金the Higher Education Discipline Innovation Project(No.B12015)“the Fundamental Research Funds for the Central Universities”Huaiyu Shao acknowledges the funding support of the Multi-Year Research Grant(MYRG)from the University of Macao(No.MYRG2022-00105-IAPME)the Joint Scientific Research Project Funding by the National Natural Science Foundation of China and the Macao Science and Technology Development Fund(No.0090/2022/AFJ)the Macao Science and Technology Development Fund(FDCT)for funding No.006/2022/ALC of the Macao Centre for Research and Development in Advanced Materials(No.2022-2024)the Natural Science Foundation of Guangdong Province(Grant No.2023A1515010765)the Shenzhen-Hong Kong-Macao Science and Technology Innovation Project(Category C).
文摘Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitting reveal two mechanisms:one shows a maximum rate at the early stage,such as V and Cr;the other needs a temperature-sensitive preparation time for its maximum rate,such as Ni.The combina-tion of two catalyst components demonstrates the best kinetics:V and Cr boost the initial dehydrogena-tion,and Ni benefits the further hydrogen transfer which alleviates the rate of decay.This work provides guidelines for the design of multi-element doped catalysts for MgH_(2) dehydrogenation.
文摘Organoboron compounds have become important intermediates for the construction of new compounds in synthetic chemistry and pharmaceutical chemistry,and it has been found that pinacol biborate(B_(2)pin_(2))as the boron source and Cu^(Ⅱ) organophosphorus complex(L)as the catalyst can effectively realize the hydrogen-reduced borylation products and dehydrohydrated borylation products of aryl olefins.The reaction regioselectivity involvingβ-C positions of aryl olefins can be controlled by regulating the ligand and additive types.The formation mechanism of the product is conducted at LCu^(Ⅰ)Bpin formed from Cu^(Ⅱ),L and B_(2)pin_(2).Subsequently the substrate aryl olefins undergo addition reaction to form the active intermediate PhCH(LCu^(Ⅰ))CH_(2)Bpin.Followed by the metathesis of the active intermediate with water to form hydrogen reduction products,the same active intermediate can be oxidized with 2,2,6,6-tetramethylpiperidoxyl(TEMPO)to form trans dehydrogenation products.
基金Project (2009AA05Z105) supported by the High-tech Research and Development Program of ChinaProject (20102173) supported by the Natural Science Foundation of Liaoning Province,China
文摘A first-principles study was reported based on density functional theory of hydrogen vacancy,metal dopants,metal dopant-vacancy complex in LiBH4,a promising material for hydrogen storage.The formation of H vacancy and metal doping in LiBH4 is difficult,and their concentrations are low.The presence of one kind of defect is helpful to the formation of other kind of defect.Based on the analysis of electronic structure,the improvement of the dehydrogenating kinetics of LiBH4 by metal catalysts is due to the weaker bonding of B—H and the new metal-like system,which makes H atom diffuse easily;H vacancy accounts for a trace amount of BH3 release during the decomposing process of LiBH4;metal dopant weakens the strength of B—H bonds,which reduces the dehydriding temperature of LiBH4.The roles of metal and vacancy in the metal dopant-vacancy complex can be added in LiBH4 system.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1506000)Gusu Innovation and Entrepreneurship Leading Talents Program(ZXL2022497)+5 种基金Jiangsu Distinguished Professor programfinancial support by National Natural Science Foundation of China(Grant No.22301057)Natural Science Foundation of Hebei Province(Grant No.B2023201065)Science Research Project of Hebei Education Department(Grant No.BJK2024103)supported by the Open Research Fund of Shanghai Key Laboratory of High-resolution Electron MicroscopyOpen Project of State Key Laboratory of Supramolecular Structure and Materials(sklssm2024019),ShanghaiTech University。
文摘The dehydrogenation of alkanes has emerged as a vital complementary process to address the increasing global demand for olefins.A key challenge remains in the construction of novel active centers that offer superior activity,stability,and cost-effectiveness.Herein,tricoordinated cobalt atoms were successfully fabricated through an in-situ ligand-protected synthesis by introducing tungsten atoms into zeolite frameworks.These unsaturated Co species efficiently activate C-H bonds while suppressing C-C bond cleavage,resulting in exceptional catalytic activity and olefin selectivity in both propane and ethane dehydrogenation reactions.The optimized Co_(0.2%)@0.01W-S-1 catalyst demonstrated an impressive propylene formation rate of 15.2 molC_(3H6)gcC h^(-1)at 823 K and an ethylene formation rate of 240.3mol_(C2H4)g_(Co)^(-1)h^(-1)at 913 K,with propylene and ethylene selectivities of 99.0%and 97.5%,respectively.These results not only significantly surpass conventional tetracoordinated Co catalysts but also rival some Pt-based catalysts under similar conditions.Importantly,the catalyst exhibited excellent stability in dehydrogenation reactions,with no significant loss in catalytic activity after five consecutive regeneration cycles.This work offers valuable insights into the design of zeolite-supported non-precious metal catalysts with high activity and durability for efficient alkane dehydrogenation.
文摘Propylene,a pivotal chemical feedstock,is extensively used in synthesizing high-value derivatives such as polypropylene and acrylonitrile[1].Although propylene is predominantly produced via naphtha cracking,a persistent supply-demand gap exists[2].Non-oil routes,such as propane dehydrogenation(PDH),are increasingly attractive,particularly with the availability of shale gas[3].Modern non-oxidative PDH heavily relies on Pt nanoparticle catalysts promoted with SnOx(e.g.,PtSn/Al2O3 used in Honeywell UOP's Oleflex process)[4].However,these systems suffer from inherent limitations:high Pt costs,coke formation via deep dehydrogenation,and sintering during regeneration-necessitating environmentally detrimental oxychlorination treatments to restore activity[5].
文摘Non-oxidative dehydrogenation of propane(PDH)is an important route for large-scale on purpose propene production.Although cobalt-based catalysts are promising alternatives to currently used platinum-or chromium oxide-based catalysts,their further developments are hindered by the uncertainties related to the kind of the active sites involved in the desired and side reactions.To contribute to closing such a gap,we systematically investigate the role of oxidized CoO_(x) and metallic Co0 species in the PDH reaction over catalysts based in Silicalite-1 with supported CoO_(x) species differing in their redox properties.C_(3)H_(8) pulse experiments with sub-millisecond and second resolution at pulse sizes of about 13 and 2200 nmol,respectively,combined with in-depth catalyst characterization and PDH tests at different propane conversions enabled us to understand how the reaction-induced reduction of CoO_(x) affects product selectivity.Propane readily reacts with CoO_(x) to yield propene,carbon oxides and water.The formed Co0 species show high activity to coking and cracking reactions.However,if the size of such species is below 2 nm,these undesired reactions are significantly hindered due to the coverage of the active sites by carbon-containing species.The remaining uncovered surface Co0 sites selectively dehydrogenate propane to propene.The best-performing catalyst showed higher activity than a commercial-like K-CrOx/Al_(2)O_(3) and operated durable in a series of 10 dehydrogenation/regeneration cycles under industrial relevant conditions.The space time yield of propene formation of 0.97 kg·h^(-1)·kgcat^(-1) was achieved at 550℃,52%equilibrium propane conversion and 95% propene selectivity.
文摘Modifying the electronic density of states and the synergistic effect of the active centers by introducing a second metal present an efficient strategy to tune physi/chemi-sorption,probably lead to improving catalytic performances.Herein,bimetallic Ni_(3)Mo/Al_(2)O_(3)catalyst was demonstrated and exhibited over 5 times more active than Pt/Al_(2)O_(3)toward the ethane dehydrogenation(EDH)as well as 2-10 times activity enhancement compared with their monometallic Ni and Mo counterparts and other Ni-based bimetallic nanoparticles.Kinetic studies revealed that the activation energy over Ni_(3)Mo/Al_(2)O_(3)(111 kJ mol^(-1))was much lower than that of Ni(157 kJ mol^(-1))and Mo(171 kJ·mol^(-1)).DFT calculations showed ethane was adsorbed on the Ni or Mo surface in a more parallel configuration,whereas over Ni_(3)Mo it adopted an inclined configuration.This change promoted ethane adsorption and pre-activation of the C-H bond,thereby benefiting the ethane dehydrogenation process on the Ni_(3)Mo surface.
基金Financial support from the National Natural Science Foundation of China(No.22271060)。
文摘The bicarbonate-formate(HCO_(3)−–HCO_(2)−)interconversion provides a promising cycle for a conveniently accessible hydrogen storage system via reversible dehydrogenation and hydrogenation processes.Existing catalytic systems often use organic solvents,tedious optimization as well as manipulation of pH values,solvent,pressure and various additives.Herein,we present an operational,robust,safe and cost-effective catalytic system for hydrogen storage and liberation.We have established a unique catalytic system with two different solid organometallic assemblies(NHC-Ru and NHC-Ir)that facilitate the reversible transformation between sodium formate and bicarbonate in aqueous solutions collaboratively and efficiently.Notably,the NHC-Ru catalyst is privileged for the hydrogenation of sodium bicarbonate,whereas the NHC-Ir component enables the dehydrogenation of sodium formate,all in a single reaction vessel.What sets this system apart is its simplicity.The H_(2)discharging and recharging is simply regulated by heating the mixture with or without H_(2).Remarkably,this process requires no extra additives or supplementary treatments.Moreover,the reversible hydrogen storage system is durable and can be reused for over 30 cycles without a discernible decline in activity and selectivity.The strategic paradigm in this study shows significant practical potential in hydrogen fuel cell applications.
文摘Photocatalytic water splitting using natural solar light is considered as a sustainable approach to generate H_(2) and O_(2).While H_(2) has high market value,the by-product of water splitting,oxygen,is less valuable.To make H_(2) produced by means of photocatalysis more economically competitive to that generated from methane,its generation is studied together with synthesis of organic compounds that have higher market value.This review summarizes and analyzes critically dehydrogenation reactions that were developed since 1980s.Photocatalytic dehydrogenation reactions are classified and the results are collected in the online database.Performance of homogeneous and heterogenous photocatalysts in dehydrogenation reactions,such as yield rates of organic products on analytical and preparative scales,and quantum efficiencies are compared.Current limitations of the existing methods and photocatalytic systems are identified and directions for the future developments are outlined.
基金National Natural Science Foundation of China,Grant/Award Numbers:21603054,31671930Innovation and entrepreneurship training program for college students of Hebei Agricultural University,Grant/Award Numbers:2019085,s202010086046+2 种基金Scientific Research Development Fund project of Hebei Agricultural University,Grant/Award Number:JY2020028the Natural Science Foundation of Hebei Province,Grant/Award Numbers:B2016204131,B2016204136Young Topnotch Talents Foundation of Hebei Provincial Universities,Grant/Award Number:BJ2016027.
文摘The single-atom M-N-C(M typically being Co or Fe)is a prominent material with exceptional reactivity in areas of catalysis for sustainable energy.However,the formation of metal nanoparticles in M-N-C materials is coupled with hightemperature calcination conditions,limiting the density of M-Nx active sites and thus restricting the catalytic performance of such catalysts.Herein,we describe an effective decoupling strategy to construct high-density M-Nx active sites by generating polyfurfuryl alcohol in the MOF precursor,effectively preventing the formation of metal nanoparticles even with up to 6.377%cobalt loading.This catalyst showed a high H_(2) production rate of 778mLgcat^(−1) h^(−1) when used in the dehydrogenation reaction of formic acid.In addition to the high density of the active site,a curved carbon surface in the structure is also thought to be the reason for the high performance of the catalyst.
文摘Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally friendly and cost-effective alternatives.In this study,we developed a facile impregnation method to fabricate unsaturated Co single-atoms with a tricoordinated Co_(1)O_(3)H_(x) structure by regulating silanol nests in purely siliceous Beta zeolites.Detailed PDH catalytic tests and characterizations revealed a positive correlation between the presence of silanol nests and enhanced catalytic activity.Additionally,the unsaturated Co single-atoms exhibited a carbon deposition rate more than an order of magnitude slower than that of Co nanoparticles.Notably,the optimized Co_(0.3%)/deAl-meso-Beta catalyst achieved a record-high propylene formation rate of 21.2 mmol_(C3H6) g_(cat)^(-1) h^(-1),with an exceptional propylene selectivity of 99.1%at 550℃.Moreover,the Co_(0.3%)/deAl-meso-Beta catalyst demonstrated excellent stability,with negligible deactivation after 5 consecutive regeneration cycles.This study emphasizes the pivotal role of silanol nests of zeolites in stabilizing and modulating the coordination environment of metallic active sites,providing valuable insights for the design of high-activity,high-stability,and low-cost PDH catalysts.
文摘Recent studies have revealed the extraordinary performance of zirconium oxide in propane dehydrogenation,which is attributed to the excellent reactivity of the coordinatively unsaturated zirconium sites(Zr_(cus))around the oxygen vacancies.The origin of the enhanced catalytic activity of ZrO_(2)with defective tetrahedral Zr sites was examined by direct comparison with its pristine counterpart in the current study.Electronic-structure analysis revealed that electrons from oxygen removal were localized within vacancies on the defective surface,which directly attacked the C-H bond in propane.The involvement of localized electrons activates the C-H bond via back-donation to the antibonding orbital on the defective surface;conversely,charge is transferred from propane to the pristine surfaces.The barrier for the first C-H bond activation is clearly significantly reduced on the defective surfaces compared to that on the pristine surfaces,which verifies the superior activity of Zr_(cus).Notably,however,the desorption of both propene and hydrogen molecules from Zr_(cus)is more difficult due to strong binding.The calculated turnover frequency(TOF)for propene formation demonstrates that the pristine surfaces exhibit better catalytic performance at lower temperatures,whereas the defective surfaces have a larger TOF at high temperatures.However,the rate-determining step and reaction order on the defective surface differ from those on the pristine surface,which corroborates that the catalysts follow different mechanisms.A further optimization strategy was proposed to address the remaining bottlenecks in propane dehydrogenation on zirconium oxide.
基金support from Zhejiang Provincial Natural Science Foundation of China(LZ23B060001).
文摘Supported metal oxide catalysts have garnered significantattention in oxidative dehydrogenation(ODH)due to their tunable metal-support interactions.The pentacoordinate Al^(3+)(Al_(V)^(3+))in γ-Al_(2)O_(3)supports plays a pivotal role in modulating metal-support interaction.This study investigates oxalic acid(OA)pretreatment as a defect engineering strategy to enhance the catalytic performance of CeO_(2)/γ-Al_(2)O_(3)in cyclohexane ODH.Through integrated characterization(XRD,27Al MAS NMR,H_(2)-TPR,TPRO,MS,XPS)and catalytic testing,we demonstrate that optimal OA treatment(1:10 ratio)eliminates 100%of surface Al_(V)^(3+)defects while enhancing CeO_(2)crystallinity and interfacial oxygen mobility.The removal of Al_(V)^(3+)species restructures metal-support interaction,accelerating interfacial oxygen mobility.In oxidation dehydrogenation of cyclohexane,the modified CeO_(2)/γ-Al_(2)O_(3)achieves 29%of cyclohexane conversion with stable selectivity of 49%cyclohexene.These findingsprovide an initial framework for designing redox-active catalysts via targeted support modificationin CeO_(2)/γ-Al_(2)O_(3)systems,emphasizing the relationship between metal-support interaction and oxygen mobility.
基金supported by the National Natural Science Foundation of China(21603054,31671930)the Natural Science Foundation of Hebei Province(B2016204136,B2016204131)+3 种基金the Young Top-notch Talents Foundation of Hebei Provincial Universities(BJ2016027)the Innovation and entrepreneurship training program for college students of Hebei Agricultural University(s202010086046,2019085)the Scientific Research Development Fund project of Hebei Agricultural University(JY2020028)the Innovation and entrepreneurship training program for college students of Hebei Agricultural University(2025019,2025198).
文摘The development of formic acid dehydrogenation materials with high activity and low cost is key to realizing hydrogen energy utilization.Herein,we describe a specific low-loading strategy to construct a high-activity Co atom site catalyst for this reaction.Under optimal conditions,the formic acid dehydrogenation performance of Co─Fe dual-atom catalyst(turnover frequency of 2,446.8 h^(−1),hydrogen production rate of 1,015,306.1 mL gCo^(−1)h^(−1))was 300 times greater than that of commercial 5%Pd/C.High-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectra,combined with theoretical calculations,confirm that the presence of different active sites(Co single-atom,Co-Co dual-atom,Co─Fe dual-atom)in catalysts is the key factor affecting their catalytic activity.These findings provide a strong scientific basis for the development of single-atom and dual-atom catalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.52272190 and 22178023)the National Key R&D Program of China(No.2021YFB4001401)。
文摘In response to the increasing demand of ethylene,electrochemical ethane nonoxidative dehydrogenation(EENDH)to ethylene by protonic ceramic electrolysis cells(PCECs)is developed.However,existing anode materials exhibit poor proton conductivity and limited catalytic activity.Herein,a novel Sr_(1.95)Fe_(1.4)Co_(0.1)Mo_(0.4)Zr_(0.1)O_(6-δ)(SFCMZ)anode is prepared as PCECs anode for EENDH.Zr doping increases the oxygen vacancies and enhances the proton conductivity of SFCMZ.Moreover,an alloy-oxide heterostructure(Co Fe@SFCMZ)is formed through in-situ exsolution of Co Fe alloy nanoparticles under reduction conditions,generating abundant oxygen vacancies and improving its catalytic activity.Co Fe@SFCMZ cell achieves an electrolysis current density of 0.87 A/cm^(2) at 700℃ under 1.6 V,with an ethane conversion rate of 34.22%and corresponding ethylene selectivity of 93.4%.These results demonstrate that Co Fe@SFCMZ anode exhibits excellent electrocatalytic activity,suggesting promising applications for EENDH.
基金supported by the National Key R&D Program of China(2023YFB3809103)the National Natural Science Foundation of China(No.52176203)+2 种基金the Key R&D Project of Shaanxi Province,China(No.2023KXJ-283)the Key R&D Project of Shaanxi Province,China(No.2024CY2-GJHX-19)the“Young Talent Support Plan”of Xi’an Jiaotong University(No.QB-A-JZB2015004)。
文摘Owing to high thermal stability and large reaction enthalpy,Mg H_(2) has high reaction temperatures and sluggish reaction kinetics in the dehydrogenation process,which consumes lots of energy.To achieve hydrogen release with low energy consumption,accelerated reaction rate,and high heating uniformity,this paper proposes a novel method of graphite responsive microwave-assisted thermal management with NaTiO_(x)H catalyst.A multi-physics model of the 5 wt%NaTiO_(x)H catalyzed Mg H_(2) reactor integrated with a microwave generator is developed to investigate the reaction,heat and mass transfer process of hydrogen release.It is found that the graphite responsive microwave heating method could improve the temperature uniformity of reaction bed,reduce the energy consumption by at least 10.71%and save the hydrogen release time by 53.49% compared with the traditional electric heating method.Moreover,the hydrogen desorption thermodynamics could be improved with the increase of microwave power.The hydrogen release time is shortened by 19.55%with the increase of 20 W microwave power.Meanwhile,it is also concluded that the microwave excitation frequency of 2.1 GHz and the graphite content of 2 wt%have better heating performance.Therefore,it can be verified that the graphite responsive microwave heating helps to low-energy and accelerated hydrogen release from MgH_(2) hydrogen storage reactor.
