In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperat...In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.展开更多
Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prep...Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol.展开更多
Cyclohexene is an important raw material in the production of nylon.Selective hydrogenation of benzene is a key method for preparing cyclohexene.However,the Ru catalysts used in current industrial processes still face...Cyclohexene is an important raw material in the production of nylon.Selective hydrogenation of benzene is a key method for preparing cyclohexene.However,the Ru catalysts used in current industrial processes still face challenges,including high metal usage,high process costs,and low cyclohexene yield.This study utilizes existing literature data combined with machine learning methods to analyze the factors influencing benzene conversion,cyclohexene selectivity,and yield in the benzene hydrogenation to cyclohexene reaction.It constructs predictive models based on XGBoost and Random Forest algorithms.After analysis,it was found that reaction time,Ru content,and space velocity are key factors influencing cyclohexene yield,selectivity,and benzene conversion.Shapley Additive Explanations(SHAP)analysis and feature importance analysis further revealed the contribution of each variable to the reaction outcomes.Additionally,we randomly generated one million variable combinations using the Dirichlet distribution to attempt to predict high-yield catalyst formulations.This paper provides new insights into the application of machine learning in heterogeneous catalysis and offers some reference for further research.展开更多
Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon...Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.展开更多
The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically in...The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃ to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.展开更多
CO_(2)utilization powered by sustainable energy offers a promising route to mitigate carbon emissions while producing value-added chemicals[1].Among these pathways,CO_(2)hydrogenation is especially attractive because ...CO_(2)utilization powered by sustainable energy offers a promising route to mitigate carbon emissions while producing value-added chemicals[1].Among these pathways,CO_(2)hydrogenation is especially attractive because it integrates renewable H 2 with carbon resources,which have achieved notable success in producing methanol,CO,etc.[2,3].展开更多
Recent advances in geoscience have underscored the critical role of abiogenic processes in petroleum formation,especially the formation and polymerization of methane.However,whether a direct carbon-H_(2) reaction can ...Recent advances in geoscience have underscored the critical role of abiogenic processes in petroleum formation,especially the formation and polymerization of methane.However,whether a direct carbon-H_(2) reaction can produce C_(2+)hydrocarbons(e.g.,ethane and propane)beyond methane remains an open question.Here,we demonstrate the direct synthesis of ethane and propane via reactions between amorphous carbon and H_(2) under upper mantle conditions(2-10 GPa and 800-1200℃).A systematic investigation reveals that increasing structural disorder in carbon precursors,from graphite to glassy carbon-Ⅱ and carbon black,enhances the production of C_(2)-C_(3) hydrocarbons.Through integrated X-ray diffraction and reverse Monte Carlo simulations,we establish that the continuous random atomic network structures in amorphous carbon enable one-step synthesis of heavy hydrocarbons with H_(2).These models establish a direct link between atomic-scale carbon structures and the one-step synthesis of C_(2+) hydrocarbons under H_(2)-rich,high-pressure,and high-temperature conditions—potentially revealing an efficient mechanism for the abiotic production of C_(2+) hydrocarbons in the upper mantle.展开更多
Endogenous hydrogen systems,consisting of metal–organic coordination catalysts and alcohols,have been widely applied for the transfer hydrogenation(TH)of biomass-derived carbonyl compounds in recent years.Metal-organ...Endogenous hydrogen systems,consisting of metal–organic coordination catalysts and alcohols,have been widely applied for the transfer hydrogenation(TH)of biomass-derived carbonyl compounds in recent years.Metal-organic coordination catalysts showed satisfactory ability of TH in the secondary alcohols,but most of them could not effectively employ the cheaper primary alcohols as hydrogen donors.Furthermore,they commonly contained high metal contents,which also led to low catalytic efficiency in significant measure.In this work,we constructed a novel magnesium single-atom catalyst(Mg-NC)with merely 0.37 wt%Mg by means of a combined self-assembly and pyrolysis strategy.The characterization results indicated that Mg was atomically dispersed and it was coordinated with four pyridinic-N in Mg-NC.Due to the obvious electron transfer from Mg to its coordinated pyridinic-N,Mg–N_(4)active centers displayed high Lewis acid-base strength with abundant content,which brought remarkable catalytic activity.When Mg-NC was used for the TH of 5-hydroxymethylfurfural(HMF)in ethanol(EtOH),2,5-bis(hydroxymethyl)furan(BHMF)yield was up to 96.3%with high productivity of 19.85 molBHMF mol_(Mg)^(−1)h^(−1)at 150°C for 5 h.More interestingly,the process of TH over Mg-NC in EtOH was proved to proceed via the hydrogen radical mechanism.Additionally,Mg-NC exhibited powerful catalytic universality;it could not only utilize other primary alcohols(such as n-propanol and n-butanol)as hydrogen donors,but also catalyze the TH of other carbonyl compounds(such as furfural,5-methylfurfural,benzaldehyde,cyclohexanone,and levulinic acid).Overall,this work offered some important clues and references to reinforce the hydrogen-supplying ability of primary alcohols in the TH of various biomass-derived carbonyl compounds to high-value fine chemicals.展开更多
Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via lo...Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.展开更多
The hydrogenation of carbon dioxide(CO_(2))to ethanol(EtOH)represents a promising strategy for carbon resource utilization.This progress advances the fields of green chemistry and renewable energy technologies.However...The hydrogenation of carbon dioxide(CO_(2))to ethanol(EtOH)represents a promising strategy for carbon resource utilization.This progress advances the fields of green chemistry and renewable energy technologies.However,its practical implementation remains hindered by challenges in catalyst development,reaction mechanism elucidation,and industrial scalability.The reaction pathway for CO_(2)hydrogenation to EtOH is intricate,involving C–O bond activation and C–C coupling,with its thermodynamic and kinetic properties strongly influenced by temperature,pressure,and catalyst structure.Briefly,CO_(2)conversion rate and EtOH selectivity are significantly enhanced by optimizing catalyst active sites,incorporating promoters and selecting appropriate supports.In recent years,multifunctional catalysts have emerged as research hotspots due to their facile structural design and superior catalytic performance.Here,it reviews the reaction mechanisms,catalyst design principles,and optimization strategies for CO_(2)hydrogenation to EtOH in the continuous-flow fixed-bed reactor with a particular emphasis on the roles of noble metals(e.g.,Rh)and transition metals(e.g.,Co,Cu)in this reaction.Future investigations should focus on deepening the mechanistic understanding of the reaction,developing efficient and stable catalysts,and optimizing the reaction conditions to enable the industrial-scale application of CO_(2)hydrogenation to EtOH in the continuous-flow fixed-bed reactor,thereby advancing green chemistry and sustainable development.展开更多
Metal-support interaction(MSI) is crucial for fine-tuning the active-site structure of supported catalysts and enhancing performance.Here,we present an ammonia-directed reactive gas-metal-support interaction(RGMSI),in...Metal-support interaction(MSI) is crucial for fine-tuning the active-site structure of supported catalysts and enhancing performance.Here,we present an ammonia-directed reactive gas-metal-support interaction(RGMSI),in which NH_(3) reduces ZnO and assembles an anti-perovskite Ni_(3)ZnN structure with interstitial nitrogen,significantly boosting hydrogenation efficiency.Nitrogen incorporation expands the lattice parameter,increasing the(111) lattice spacing from 2.04Å in Ni to 2.18Å in Ni_(3)ZnN,with an extended Ni-Ni interatomic distance from 2.49Å to 2.65Å.Additionally,Ni-N coordination shifts the d-band center downward and induces electron deficiency in Ni via charge transfer.These modifications optimize reactant adsorption on the tailored Ni_(3)ZnN structure compared to Ni,leading to a remarkable increase in 1,3-butadiene hydrogenation selectivity from 30.0 % to 92.9 %,along with an enhanced TOF from 0.067 s^(-1) to 0.079 s^(-1).These findings highlight RGMSI as a versatile and effective strategy for designing supported metal catalysts,offering new insights into selective hydrogenation catalysis.展开更多
Significant increase of specific target olefin selectivity in CO_(2)hydrogenation is not only scientifically interesting but also practically valuable because of the reduction of separation cost.Here,a new composite c...Significant increase of specific target olefin selectivity in CO_(2)hydrogenation is not only scientifically interesting but also practically valuable because of the reduction of separation cost.Here,a new composite catalyst is fabricated with surface oxygen vacancy-abundant ZnZrO_(x)(H)solid solution and ultra-small H-SAPO-34(US)molecular sieve crystals.This catalyst shows a propene selectivity in hydrocarbons of 51.2%that accounts for about 63%of light olefins,along with a CO_(2)conversion of 13.5%,at 350°C and 3.0 MPa.A combination of in situ spectroscopy,isotope-labelled experiments,DFT calculations,and AIMD simulations reveals that an increase of surface oxygen vacancies in ZnZrO_(x)(H)induces formation of a coordinatively unsaturated(Zr-O)_(n)-Zn-(Ov)_(m)configuration,which elevates Zn site electron density and enhances the electronic interaction of Zn-3d and H-1s orbitals.This promotes the H_(2)dissociation and facilitates methanol intermediate formation.The ultra-small H-SAPO-34(US)crystals with a size of 100–200 nm effectively suppresses alkenes hydrogenation and subsequent aromatization in the methanol conversion process.As a result,more propene was produced.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
The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively red...The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.展开更多
Hydrogenation reactions,vital in chemical engineering,are hampered by limitations including catalyst recovery,mass transfer issues,and scalability.Catalytic membrane reactors offer a promising alternative by integrati...Hydrogenation reactions,vital in chemical engineering,are hampered by limitations including catalyst recovery,mass transfer issues,and scalability.Catalytic membrane reactors offer a promising alternative by integrating reaction and separation,boosting efficiency and simplifying catalyst handling.However,scaling these membranes to industrial levels while ensuring long-term stability and high efficiency remains a significant challenge.This study tackles this by developing and demonstrating a pilot-scale multi-channel ceramic catalytic membrane reactor system.This system,featuring three 19-channel ceramic catalytic membranes,achieved nearly 100%p-nitrophenol hydrogenation conversion consistently over 600 h of continuous liquid-phase operation.This underscores the superior catalytic efficiency,remarkable long-term stability,and strong scalability of multi-channel ceramic catalytic membrane.This work establishes a robust platform for continuous-flow hydrogenation,providing a solid foundation for practical catalytic membrane reactor technology application in the chemical industry.展开更多
The semi-hydrogenation of alkynes to alkenes is of great significance in the industrial production of pharmaceutical and fine chemicals.Electrochemical semi-hydrogenation(ECSH)has emerged as a promising alternative to...The semi-hydrogenation of alkynes to alkenes is of great significance in the industrial production of pharmaceutical and fine chemicals.Electrochemical semi-hydrogenation(ECSH)has emerged as a promising alternative to conventional thermochemical hydrogenation.However,its practical application is hindered by low reaction rate and competing hydrogen evolution reaction(HER).In this work,the controllable incorporation of sulfur into the lattice of Pd nanostructures is proposed to develop disordered and electron-deficient Pd-based nanosheets on Ni foam and enhance their ECSH performance of alkynes.Mechanistic investigations demonstrate that the electronic and geometric structures of Pd sites are optimized by lattice sulfur,which tunes the competitive adsorption of H*and alkynes,inherently inhibits the H*coupling and weakens alkene adsorption,thereby promotes the semi-hydrogenation of alkynes and prevents the over-hydrogenation of alkenes.The optimized Pd-based nanosheets exhibit efficient electrocatalytic semi-hydrogenation performance in an H-cell,achieving 97%alkene selectivity,94%Faradaic efficiency,and a reaction rate of 303.7μmol mgcatal.^(-1) h^(-1) using 4-methoxyphenylacetylene as the model substrate.Even in a membrane electrode assembly(MEA)configuration,the optimized Pd-based nanosheets achieves a single-cycle alkyne conversion of 96%and an alkene selectivity of 97%,with continuous production of alkene at a rate of 1901.1μmol mgcatal.^(-1) h^(-1).The potential-and time-independent selectivity,good substrate universality with excellent tolerance to active groups(C–Br/Cl/C]O,etc.)further highlight the potential of this strategy for advanced catalysts design and green chemistry.展开更多
CO_(2)hydrogenation to value-added light olefins(C_(2-4)=)is crucial for the utilization and cycling of global carbon resource.Moderate CO_(2)activation and carbon chain growth ability are key factors for iron-based c...CO_(2)hydrogenation to value-added light olefins(C_(2-4)=)is crucial for the utilization and cycling of global carbon resource.Moderate CO_(2)activation and carbon chain growth ability are key factors for iron-based catalysts for efficient CO_(2)conversion to target C_(2-4)=products.The electronic interaction and confinement effect of electron-deficient graphene inner surface on the active phase are effective to improve surface chemical properties and enhance the catalytic performance.Here,we report a core-shell FeCo alloy catalyst with graphene layers confinement prepared by a simple sol-gel method.The electron transfer from Fe species to curved graphene inner surface modifies the surface electronic structure of the active phaseχ-(Fe_(x)Co_(1-x))_(5)C_(2)and improves CO_(2)adsorption capacity,enhancing the efficient conversion of CO_(2)and moderate C-C coupling.Therefore,the catalyst FeCoK@C exhibits C_(2-4)=selectivity of 33.0%while maintaining high CO_(2)conversion of 52.0%.The high stability without obvious deactivation for over 100 h and unprecedented C_(2-4)=space time yield(STY)up to 52.9 mmolCO_(2)·g^(-1)·h^(-1)demonstrate its potential for practical application.This work provides an efficient strategy for the development of high-performance CO_(2)hydrogenation catalysts.展开更多
The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly unders...The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly understood due to challenges in atomic-level structural characterizations and analysis of reaction intermediates.In this study,we prepared two Zn-Al spinel oxide catalysts via coprecipitation(ZnAl-C)and hydrothermal(ZnAl-H)methods,and conducted a comparative investigation in the CO_(2)hydrogenation reaction.Surprisingly,under similar conditions,ZnAl-C exhibited significantly higher selectivity towards methanol and DME compared to ZnAl-H.Comprehensive characterizations using X-ray diffraction(XRD),Raman spectroscopy and electron paramagnetic resonance(EPR)unveiled that ZnAl-C catalyst had abundant ZnO species on its surface,and the interaction between the ZnO species and its ZnAl spinel oxide matrix led to the formation of oxygen vacancies,which are crucial for CO_(2)adsorption and activation.Additionally,state-of-the-art solid-state nuclear magnetic resonance(NMR)techniques,including ex-situ and in-situ NMR analyses,confirmed that the surface ZnO facilitates the formation of unique highly reactive interfacial formate species,which was readily hydrogenated to methanol and DME.These insights elucidate the promotion effects of ZnO on the ZnAl spinel oxide in regulating active sites and reactive intermediates for CO_(2)-to-methanol hydrogenation reaction,which is further evidenced by the significant enhancement in methanol and DME selectivity observed upon loading ZnO onto the ZnAl-H catalyst.These molecular-level mechanism understandings reinforce the idea of optimizing the ZnO-ZnAl interface through tailored synthesis methods to achieve activity-selectivity balance.展开更多
As one of the most important industrially viable methods for carbon dioxide(CO_(2))utilization,methanol synthesis serves as a platform for production of green fuels and commodity chemicals.For sustainable methanol syn...As one of the most important industrially viable methods for carbon dioxide(CO_(2))utilization,methanol synthesis serves as a platform for production of green fuels and commodity chemicals.For sustainable methanol synthesis,In_(2)O_(3)is an ideal catalyst and has garnered significant attention.Herein,cubic In_(2)O_(3)nanoparticles were prepared via the precipitation method and evaluated for CO_(2)hydrogenation to produce methanol.During the initial 10 h of reaction,CO_(2)conversion gradually increased,accompanied by a slow decrease of methanol selectivity,and the reaction reached equilibrium after 10-20 h on stream.This activation and induction stage may be attributed to the sintering of In_(2)O_(3)nanoparticles and the creation of more oxygen vacancies on In_(2)O_(3)surfaces.Further experimental studies demonstrate that hydrogen induction created additional oxygen vacancies during the catalyst activation stage,enhancing the performance of In_(2)O_(3)catalyst for CO_(2)hydrogenation.Density functional theory calculations and microkinetic simulations further demonstrated that surfaces with higher oxygen vacancy coverages or hydroxylated surfaces formed during this induction period can enhance the reaction rate and increase the CO_(2)conversion.However,they predominantly promote the formation of CO instead of methanol,leading to reduced methanol selectivity.These predictions align well with the above-mentioned experimental observations.Our work thus provides an in-depth analysis of the induction stage of the CO_(2)hydrogenation process on In_(2)O_(3)nano-catalyst,and offers valuable insights for significantly improving the CO_(2)reactivity of In_(2)O_(3)-based catalysts while maintaining long-term stability.展开更多
Molybdenum carbide has shown great potential in various hydrogenation reactions,and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in th...Molybdenum carbide has shown great potential in various hydrogenation reactions,and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in the efficient utilization of coal resources.In this study,a molybdenum carbide catalyst with a three-dimensional mesh-like hollow structure and lattice defects was carefully designed.The MoO_(3)precursor with abundant oxygen vacancies and defects was prepared by flame spray pyrolysis,and a structural modifier,Cu,was introduced by sputtering.The Cu deposited by sputtering affected the carburization and phase evolution processes.A three-dimensional mesh-like hollow structure composed of defective molybdenum carbide is formed,with theβ-Mo_(2)C exhibiting lattice distortions and defects.This defectiveβ-Mo_(2)C exhibits high reactivity,and facilitates the C=O hydrogenation process,showing a high reactivity of 83.1%yield in the hydrogenation of dimethyl oxalate.This work provides a new approach to the design and application of molybdenum carbide catalysts.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12074213 and 11574108)the Major Basic Program of Natural Science Foundation of Shandong Province (Grant No.ZR2021ZD01)the Natural Science Foundation of Shandong Province (Grant No.ZR2023MA082)。
文摘In recent years,the research on superconductivity in one-dimensional(1D)materials has been attracting increasing attention due to its potential applications in low-dimensional nanodevices.However,the critical temperature(T_(c))of 1D superconductors is low.In this work,we theoretically investigate the possible high T_(c) superconductivity of(5,5)carbon nanotube(CNT).The pristine(5,5)CNT is a Dirac semimetal and can be modulated into a semiconductor by full hydrogenation.Interestingly,by further hole doping,it can be regulated into a metallic state with the sp^(3)-hybridized σ electrons metalized,and a giant Kohn anomaly appears in the optical phonons.The two factors together enhance the electron–phonon coupling,and lead to high-T_(c) superconductivity.When the hole doping concentration of hydrogenated-(5,5)CNT is 2.5 hole/cell,the calculated T_(c) is 82.3 K,exceeding the boiling point of liquid nitrogen.Therefore,the predicted hole-doped hydrogenated-(5,5)CNT provides a new platform for 1D high-T_(c) superconductivity and may have potential applications in 1D nanodevices.
基金Supported by National Key R&D Program of China(2022YFA1503400)。
文摘Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol.
基金Supported by CAS Basic and Interdisciplinary Frontier Scientific Research Pilot Project(XDB1190300,XDB1190302)Youth Innovation Promotion Association CAS(Y2021056)+1 种基金Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2022007)The special fund for Science and Technology Innovation Teams of Shanxi Province(202304051001007)。
文摘Cyclohexene is an important raw material in the production of nylon.Selective hydrogenation of benzene is a key method for preparing cyclohexene.However,the Ru catalysts used in current industrial processes still face challenges,including high metal usage,high process costs,and low cyclohexene yield.This study utilizes existing literature data combined with machine learning methods to analyze the factors influencing benzene conversion,cyclohexene selectivity,and yield in the benzene hydrogenation to cyclohexene reaction.It constructs predictive models based on XGBoost and Random Forest algorithms.After analysis,it was found that reaction time,Ru content,and space velocity are key factors influencing cyclohexene yield,selectivity,and benzene conversion.Shapley Additive Explanations(SHAP)analysis and feature importance analysis further revealed the contribution of each variable to the reaction outcomes.Additionally,we randomly generated one million variable combinations using the Dirichlet distribution to attempt to predict high-yield catalyst formulations.This paper provides new insights into the application of machine learning in heterogeneous catalysis and offers some reference for further research.
基金Supported by the National Key Research and Development Program of China(2023YFB4104500,2023YFB4104502)the National Natural Science Foundation of China(22138013)the Taishan Scholar Project(ts201712020).
文摘Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.
文摘The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃ to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.
文摘CO_(2)utilization powered by sustainable energy offers a promising route to mitigate carbon emissions while producing value-added chemicals[1].Among these pathways,CO_(2)hydrogenation is especially attractive because it integrates renewable H 2 with carbon resources,which have achieved notable success in producing methanol,CO,etc.[2,3].
基金mainly supported by the Natural Science Foundation of China (Grant Nos. 52288102, 52090020, and 52372261)the Natural Science Foundation of Hebei Province (Grant No. E202403045)+1 种基金the S&T Program of Hebei (Grant No. 225A1102D)the Ministry of Education Chang Jiang Scholar Professor Program (Grant No. T2022241)
文摘Recent advances in geoscience have underscored the critical role of abiogenic processes in petroleum formation,especially the formation and polymerization of methane.However,whether a direct carbon-H_(2) reaction can produce C_(2+)hydrocarbons(e.g.,ethane and propane)beyond methane remains an open question.Here,we demonstrate the direct synthesis of ethane and propane via reactions between amorphous carbon and H_(2) under upper mantle conditions(2-10 GPa and 800-1200℃).A systematic investigation reveals that increasing structural disorder in carbon precursors,from graphite to glassy carbon-Ⅱ and carbon black,enhances the production of C_(2)-C_(3) hydrocarbons.Through integrated X-ray diffraction and reverse Monte Carlo simulations,we establish that the continuous random atomic network structures in amorphous carbon enable one-step synthesis of heavy hydrocarbons with H_(2).These models establish a direct link between atomic-scale carbon structures and the one-step synthesis of C_(2+) hydrocarbons under H_(2)-rich,high-pressure,and high-temperature conditions—potentially revealing an efficient mechanism for the abiotic production of C_(2+) hydrocarbons in the upper mantle.
基金financially supported by the National Natural Science Foundation of China(U22A20421)the Qinglan Project of Jiangsu Province,the 533 Talent Program of Huaian City,and the College Students’Innovative Entrepreneurial Training Plan Program of Jiangsu Province(X202510323027).
文摘Endogenous hydrogen systems,consisting of metal–organic coordination catalysts and alcohols,have been widely applied for the transfer hydrogenation(TH)of biomass-derived carbonyl compounds in recent years.Metal-organic coordination catalysts showed satisfactory ability of TH in the secondary alcohols,but most of them could not effectively employ the cheaper primary alcohols as hydrogen donors.Furthermore,they commonly contained high metal contents,which also led to low catalytic efficiency in significant measure.In this work,we constructed a novel magnesium single-atom catalyst(Mg-NC)with merely 0.37 wt%Mg by means of a combined self-assembly and pyrolysis strategy.The characterization results indicated that Mg was atomically dispersed and it was coordinated with four pyridinic-N in Mg-NC.Due to the obvious electron transfer from Mg to its coordinated pyridinic-N,Mg–N_(4)active centers displayed high Lewis acid-base strength with abundant content,which brought remarkable catalytic activity.When Mg-NC was used for the TH of 5-hydroxymethylfurfural(HMF)in ethanol(EtOH),2,5-bis(hydroxymethyl)furan(BHMF)yield was up to 96.3%with high productivity of 19.85 molBHMF mol_(Mg)^(−1)h^(−1)at 150°C for 5 h.More interestingly,the process of TH over Mg-NC in EtOH was proved to proceed via the hydrogen radical mechanism.Additionally,Mg-NC exhibited powerful catalytic universality;it could not only utilize other primary alcohols(such as n-propanol and n-butanol)as hydrogen donors,but also catalyze the TH of other carbonyl compounds(such as furfural,5-methylfurfural,benzaldehyde,cyclohexanone,and levulinic acid).Overall,this work offered some important clues and references to reinforce the hydrogen-supplying ability of primary alcohols in the TH of various biomass-derived carbonyl compounds to high-value fine chemicals.
基金the National Nature Science Foundation of China for Excellent Young Scientists Fund(32222058)Fundamental Research Foundation of CAF(CAFYBB2022QB001).
文摘Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.
基金supported by the National Key Research and Development Program of China(2022YFB4101800)the National Natural Science Foundation of China(22172032,U22A20431)。
文摘The hydrogenation of carbon dioxide(CO_(2))to ethanol(EtOH)represents a promising strategy for carbon resource utilization.This progress advances the fields of green chemistry and renewable energy technologies.However,its practical implementation remains hindered by challenges in catalyst development,reaction mechanism elucidation,and industrial scalability.The reaction pathway for CO_(2)hydrogenation to EtOH is intricate,involving C–O bond activation and C–C coupling,with its thermodynamic and kinetic properties strongly influenced by temperature,pressure,and catalyst structure.Briefly,CO_(2)conversion rate and EtOH selectivity are significantly enhanced by optimizing catalyst active sites,incorporating promoters and selecting appropriate supports.In recent years,multifunctional catalysts have emerged as research hotspots due to their facile structural design and superior catalytic performance.Here,it reviews the reaction mechanisms,catalyst design principles,and optimization strategies for CO_(2)hydrogenation to EtOH in the continuous-flow fixed-bed reactor with a particular emphasis on the roles of noble metals(e.g.,Rh)and transition metals(e.g.,Co,Cu)in this reaction.Future investigations should focus on deepening the mechanistic understanding of the reaction,developing efficient and stable catalysts,and optimizing the reaction conditions to enable the industrial-scale application of CO_(2)hydrogenation to EtOH in the continuous-flow fixed-bed reactor,thereby advancing green chemistry and sustainable development.
基金the financial support provided by the National Natural Science Foundation of China (Nos.22072164,22472180,22002173)Energy Revolution S&T Program of Yulin Innovation Institute of Clean Energy (No.E411030705)+2 种基金Natural Science Foundation of Liaoning Province (No.2022-MS004)China Postdoctoral Science Foundation (No.2020M680999)the Research Fund of Shenyang National Laboratory for Materials Science。
文摘Metal-support interaction(MSI) is crucial for fine-tuning the active-site structure of supported catalysts and enhancing performance.Here,we present an ammonia-directed reactive gas-metal-support interaction(RGMSI),in which NH_(3) reduces ZnO and assembles an anti-perovskite Ni_(3)ZnN structure with interstitial nitrogen,significantly boosting hydrogenation efficiency.Nitrogen incorporation expands the lattice parameter,increasing the(111) lattice spacing from 2.04Å in Ni to 2.18Å in Ni_(3)ZnN,with an extended Ni-Ni interatomic distance from 2.49Å to 2.65Å.Additionally,Ni-N coordination shifts the d-band center downward and induces electron deficiency in Ni via charge transfer.These modifications optimize reactant adsorption on the tailored Ni_(3)ZnN structure compared to Ni,leading to a remarkable increase in 1,3-butadiene hydrogenation selectivity from 30.0 % to 92.9 %,along with an enhanced TOF from 0.067 s^(-1) to 0.079 s^(-1).These findings highlight RGMSI as a versatile and effective strategy for designing supported metal catalysts,offering new insights into selective hydrogenation catalysis.
基金supported by the National Key R&D Program of China(2023YFB4103102)National Natural Science Foundation of China(21991090,21991092,22322208,22272195,U22A20431)+2 种基金the Basic Research Program of Shanxi Province of China(202203021224009)Innovation foundation of Institute of Coal Chemistry,Chinese Academy of Sciences(SCJC-DT-2023-06)Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS)(2021172).
文摘Significant increase of specific target olefin selectivity in CO_(2)hydrogenation is not only scientifically interesting but also practically valuable because of the reduction of separation cost.Here,a new composite catalyst is fabricated with surface oxygen vacancy-abundant ZnZrO_(x)(H)solid solution and ultra-small H-SAPO-34(US)molecular sieve crystals.This catalyst shows a propene selectivity in hydrocarbons of 51.2%that accounts for about 63%of light olefins,along with a CO_(2)conversion of 13.5%,at 350°C and 3.0 MPa.A combination of in situ spectroscopy,isotope-labelled experiments,DFT calculations,and AIMD simulations reveals that an increase of surface oxygen vacancies in ZnZrO_(x)(H)induces formation of a coordinatively unsaturated(Zr-O)_(n)-Zn-(Ov)_(m)configuration,which elevates Zn site electron density and enhances the electronic interaction of Zn-3d and H-1s orbitals.This promotes the H_(2)dissociation and facilitates methanol intermediate formation.The ultra-small H-SAPO-34(US)crystals with a size of 100–200 nm effectively suppresses alkenes hydrogenation and subsequent aromatization in the methanol conversion process.As a result,more propene was produced.
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.
文摘The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.
基金financial support from the National Key R&D Program(2022YFB3805504)the National Natural Science Foundation(U24A20536,U23A20117,22208149,22278209,22178165,21921006)the Natural Science Foundation of Jiangsu Province(BK20220354,BK20211262)of China.
文摘Hydrogenation reactions,vital in chemical engineering,are hampered by limitations including catalyst recovery,mass transfer issues,and scalability.Catalytic membrane reactors offer a promising alternative by integrating reaction and separation,boosting efficiency and simplifying catalyst handling.However,scaling these membranes to industrial levels while ensuring long-term stability and high efficiency remains a significant challenge.This study tackles this by developing and demonstrating a pilot-scale multi-channel ceramic catalytic membrane reactor system.This system,featuring three 19-channel ceramic catalytic membranes,achieved nearly 100%p-nitrophenol hydrogenation conversion consistently over 600 h of continuous liquid-phase operation.This underscores the superior catalytic efficiency,remarkable long-term stability,and strong scalability of multi-channel ceramic catalytic membrane.This work establishes a robust platform for continuous-flow hydrogenation,providing a solid foundation for practical catalytic membrane reactor technology application in the chemical industry.
基金financially supported by the National Natural Science Foundation of China(51701127,92163209,12264053)Shenzhen Fundamental Research Program(JCYJ20220811170904003,JCYJ20210324094000001)+6 种基金Shenzhen Peacock Plan(20180703896C)Shenzhen Key Laboratory of 2D Metamaterials for Information Technology(ZDSYS201707271014468)the research projects of Guangdong Provincial Education Office(2024KCXTD064)ZJUHIC start-up fund(02090200-K02013002)Beijing Natural Science Foundation(JQ22004)the Natural Science Foundation of Hangzhou(2024SZRYBB020001)the Scientific Research and Innovation Project of Postgraduate Students in the Academic Degree of Yunnan University(KC-23234366).
文摘The semi-hydrogenation of alkynes to alkenes is of great significance in the industrial production of pharmaceutical and fine chemicals.Electrochemical semi-hydrogenation(ECSH)has emerged as a promising alternative to conventional thermochemical hydrogenation.However,its practical application is hindered by low reaction rate and competing hydrogen evolution reaction(HER).In this work,the controllable incorporation of sulfur into the lattice of Pd nanostructures is proposed to develop disordered and electron-deficient Pd-based nanosheets on Ni foam and enhance their ECSH performance of alkynes.Mechanistic investigations demonstrate that the electronic and geometric structures of Pd sites are optimized by lattice sulfur,which tunes the competitive adsorption of H*and alkynes,inherently inhibits the H*coupling and weakens alkene adsorption,thereby promotes the semi-hydrogenation of alkynes and prevents the over-hydrogenation of alkenes.The optimized Pd-based nanosheets exhibit efficient electrocatalytic semi-hydrogenation performance in an H-cell,achieving 97%alkene selectivity,94%Faradaic efficiency,and a reaction rate of 303.7μmol mgcatal.^(-1) h^(-1) using 4-methoxyphenylacetylene as the model substrate.Even in a membrane electrode assembly(MEA)configuration,the optimized Pd-based nanosheets achieves a single-cycle alkyne conversion of 96%and an alkene selectivity of 97%,with continuous production of alkene at a rate of 1901.1μmol mgcatal.^(-1) h^(-1).The potential-and time-independent selectivity,good substrate universality with excellent tolerance to active groups(C–Br/Cl/C]O,etc.)further highlight the potential of this strategy for advanced catalysts design and green chemistry.
文摘CO_(2)hydrogenation to value-added light olefins(C_(2-4)=)is crucial for the utilization and cycling of global carbon resource.Moderate CO_(2)activation and carbon chain growth ability are key factors for iron-based catalysts for efficient CO_(2)conversion to target C_(2-4)=products.The electronic interaction and confinement effect of electron-deficient graphene inner surface on the active phase are effective to improve surface chemical properties and enhance the catalytic performance.Here,we report a core-shell FeCo alloy catalyst with graphene layers confinement prepared by a simple sol-gel method.The electron transfer from Fe species to curved graphene inner surface modifies the surface electronic structure of the active phaseχ-(Fe_(x)Co_(1-x))_(5)C_(2)and improves CO_(2)adsorption capacity,enhancing the efficient conversion of CO_(2)and moderate C-C coupling.Therefore,the catalyst FeCoK@C exhibits C_(2-4)=selectivity of 33.0%while maintaining high CO_(2)conversion of 52.0%.The high stability without obvious deactivation for over 100 h and unprecedented C_(2-4)=space time yield(STY)up to 52.9 mmolCO_(2)·g^(-1)·h^(-1)demonstrate its potential for practical application.This work provides an efficient strategy for the development of high-performance CO_(2)hydrogenation catalysts.
基金financially National Key R&D Program of China(No.2022YFA1504800)National Natural Science Foundation of China(Grant No.22325405,22372160,22321002)+1 种基金Liaoning Revitalization Talents Program(XLYC1807207)DICP I202104。
文摘The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly understood due to challenges in atomic-level structural characterizations and analysis of reaction intermediates.In this study,we prepared two Zn-Al spinel oxide catalysts via coprecipitation(ZnAl-C)and hydrothermal(ZnAl-H)methods,and conducted a comparative investigation in the CO_(2)hydrogenation reaction.Surprisingly,under similar conditions,ZnAl-C exhibited significantly higher selectivity towards methanol and DME compared to ZnAl-H.Comprehensive characterizations using X-ray diffraction(XRD),Raman spectroscopy and electron paramagnetic resonance(EPR)unveiled that ZnAl-C catalyst had abundant ZnO species on its surface,and the interaction between the ZnO species and its ZnAl spinel oxide matrix led to the formation of oxygen vacancies,which are crucial for CO_(2)adsorption and activation.Additionally,state-of-the-art solid-state nuclear magnetic resonance(NMR)techniques,including ex-situ and in-situ NMR analyses,confirmed that the surface ZnO facilitates the formation of unique highly reactive interfacial formate species,which was readily hydrogenated to methanol and DME.These insights elucidate the promotion effects of ZnO on the ZnAl spinel oxide in regulating active sites and reactive intermediates for CO_(2)-to-methanol hydrogenation reaction,which is further evidenced by the significant enhancement in methanol and DME selectivity observed upon loading ZnO onto the ZnAl-H catalyst.These molecular-level mechanism understandings reinforce the idea of optimizing the ZnO-ZnAl interface through tailored synthesis methods to achieve activity-selectivity balance.
文摘As one of the most important industrially viable methods for carbon dioxide(CO_(2))utilization,methanol synthesis serves as a platform for production of green fuels and commodity chemicals.For sustainable methanol synthesis,In_(2)O_(3)is an ideal catalyst and has garnered significant attention.Herein,cubic In_(2)O_(3)nanoparticles were prepared via the precipitation method and evaluated for CO_(2)hydrogenation to produce methanol.During the initial 10 h of reaction,CO_(2)conversion gradually increased,accompanied by a slow decrease of methanol selectivity,and the reaction reached equilibrium after 10-20 h on stream.This activation and induction stage may be attributed to the sintering of In_(2)O_(3)nanoparticles and the creation of more oxygen vacancies on In_(2)O_(3)surfaces.Further experimental studies demonstrate that hydrogen induction created additional oxygen vacancies during the catalyst activation stage,enhancing the performance of In_(2)O_(3)catalyst for CO_(2)hydrogenation.Density functional theory calculations and microkinetic simulations further demonstrated that surfaces with higher oxygen vacancy coverages or hydroxylated surfaces formed during this induction period can enhance the reaction rate and increase the CO_(2)conversion.However,they predominantly promote the formation of CO instead of methanol,leading to reduced methanol selectivity.These predictions align well with the above-mentioned experimental observations.Our work thus provides an in-depth analysis of the induction stage of the CO_(2)hydrogenation process on In_(2)O_(3)nano-catalyst,and offers valuable insights for significantly improving the CO_(2)reactivity of In_(2)O_(3)-based catalysts while maintaining long-term stability.
文摘Molybdenum carbide has shown great potential in various hydrogenation reactions,and serves as a primary active species for synthesis of ethanol from dimethyl oxalate hydrogenation process which is a crucial step in the efficient utilization of coal resources.In this study,a molybdenum carbide catalyst with a three-dimensional mesh-like hollow structure and lattice defects was carefully designed.The MoO_(3)precursor with abundant oxygen vacancies and defects was prepared by flame spray pyrolysis,and a structural modifier,Cu,was introduced by sputtering.The Cu deposited by sputtering affected the carburization and phase evolution processes.A three-dimensional mesh-like hollow structure composed of defective molybdenum carbide is formed,with theβ-Mo_(2)C exhibiting lattice distortions and defects.This defectiveβ-Mo_(2)C exhibits high reactivity,and facilitates the C=O hydrogenation process,showing a high reactivity of 83.1%yield in the hydrogenation of dimethyl oxalate.This work provides a new approach to the design and application of molybdenum carbide catalysts.
