Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effectiv...Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.展开更多
Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catal...Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.展开更多
Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardan...Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardant strategies often compromise their mechanical properties,hindering their practical applications.Herein,a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)-based comonomer(DDP)was used to synthesize flame-retardant poly(ethylene furandicarboxylate-co-phosphaphenanthrene)(PEFDn).The covalent integration of DDP confers intrinsic flame retardancy,avoiding the plasticization and migration issues associated with additive-type systems.Upon thermal decomposition,the DOPO-derived moieties release phosphoric acid and radical scavengers,promoting char formation and suppressing flame propagation.Furthermore,density functional theory(DFT)calculations combined with non-covalent interaction(NCI)analysis revealed that DOPO dimer molecules adopt a stable parallel-displaced π-π stacking configu ration,potentially facilitating microphase separation and enhancing the energy dissipation capability.PEFD_(10)achieves a UL-94 V-0 rating while simultaneously increasing impact toughness from 1.5 kJ/m^(2) to 14.7 kJ/m^(2).Im portantly,PEFDn maintained acceptable oxygen-barrier properties.PEFD10 also exhibited high transparency and UV-shielding performance.The combination of intrinsic flame safety,im pact-toughness resistance,UV shielding,and an oxygen barrier ensures reliable protection of electrical components and long-term operational stability.The integration of multiple critical properties within a single bio-based material represents a novel approach fo r enabling sustainable polymer solutions for high-pe rformance electrical applications.展开更多
Although the efficiency of poly(ethylene terephthalate)(PET)degradation has been successfully improved by depolymerase engineering,mostly by using Goodfellow-PET(gf-PET)as a substrate,efforts to degrade unpretreated P...Although the efficiency of poly(ethylene terephthalate)(PET)degradation has been successfully improved by depolymerase engineering,mostly by using Goodfellow-PET(gf-PET)as a substrate,efforts to degrade unpretreated PET materials with high crystallinity remain insufficient.Here,we endeavored to improve the degradation capability of a WCCG mutant of leaf-branch compost cutinase(LCC)on a unpretreated PET substrate(crystallinity>40%)by employing iterative saturation mutagenesis.Using this method,we developed a high-throughput screening strategy appropriate for unpretreated substrates.Through extensive screening of residues around the substrate-binding groove,two variants,WCCG-sup1 and WCCG-sup2,showed good depolymerization capabilities with both high-(42%)and low-crystallinity(9%)substrates.The WCCG-sup1 variant completely depolymerized a commercial unpretreated PET product in 36 h at 72℃.In addition to enzyme thermostability and catalytic efficiency,the adsorption of enzymes onto substrates plays an important role in PET degradation.This study provides valuable insights into the structure-function relationship of LCC.展开更多
Ethylene glycol(EG)is a biomass derivative of polyethylene terephthalate(PET),and its electrocatalytic conversion into high-value chemicals has sparked widespread interest.This study reviews the most recent research d...Ethylene glycol(EG)is a biomass derivative of polyethylene terephthalate(PET),and its electrocatalytic conversion into high-value chemicals has sparked widespread interest.This study reviews the most recent research development in electrocatalysis-based EG to glycolic acid(GA)conversion.Firstly,the strategies and research results of modulating the electronic structure of catalysts for efficient selective GA production from EG are reviewed.Second,by reviewing the data of in-situ Fourier transform infrared spectroscopy and in-situ electrochemically attenuated total reflection surface enhanced infrared absorption spectroscopy,the reaction pathway and catalytic mechanism of EG partial oxidation to GA were clarified.Finally,the design and regulation of catalysts for selective oxidation of EG by electrocatalysis in the future are prospected.展开更多
The synthesis of polyurethanes(PUs)from the reaction of low molecular weight poly(ethylene carbonate)diol(PECD)is rarely investigated.This work reports a novel PU with excellent mechanical properties from the solution...The synthesis of polyurethanes(PUs)from the reaction of low molecular weight poly(ethylene carbonate)diol(PECD)is rarely investigated.This work reports a novel PU with excellent mechanical properties from the solution polymerization of 4,4-diphenylmethane diisocyanate(MDI)with PECD that was derived from the copolymerization of carbon dioxide(CO_(2))and ethylene oxide(EO).The tensile strength,the elongation at break and 300%constant tensile strength of the PECD-PU were up to 66±2 MPa,880%±50%and 13 MPa,respectively,higher than the control PUs from the reaction of MDI with commercial polyethers or polyesters.The PECD-PU with high CO_(2) carbonate content exhibited good solvent resistance and chemical stability.Of importance,the mechanical properties and chemical resistance of PECD-PU were significantly enhanced with the increasing content of CO_(2),i.e.,the carbonate unit in PECD.This work provides comprehensive properties of PECD-derived PUs,indicating that PECD is a competitive precursor for the preparation of PU and has broad application prospects.展开更多
Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In t...Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.展开更多
Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(...Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(CO_(2)).With a maximal EDA conversion of 82%and EU selectivity of 99%at 160℃ for 2 h,Mn_(2)O_(3) catalysts had the best catalytic activity among them,which was superior to the reported catalysts.In the following order:Mn_(2)O_(3)>MnO_(2)>Mn_(3)O_(4),the catalytic activity for the synthesis of EU from CO_(2) and EDA decreased.Further characterization showed the Mn_(2)O_(3) catalyst possessed a greater Mn^(3+)/Mn4+ratio and more surface oxygen vacancies than the MnO_(2) and Mn_(3)O_(4),which improved its capacity to adsorb and activate CO_(2) and EDA.After four recycling runs,the EDA conversion slightly declined from 82%to 56%on Mn_(2)O_(3) catalyst,while no obvious change in EU selectivity was observed.The loss of surface Ov contents and Mn^(3+)proportion were concluded as main reasons for the decrease in catalytic activity over Mn_(2)O_(3) catalyst.This work demonstrated a metal oxide catalyst that was efficient in producing EU from CO_(2) and EDA.展开更多
Polyamines(PAs)and ethylene are involved in the modulation of plant growth and development.However,their roles in fruit-set,especially in exogenous gibberellin(GA_(3))-induced grape parthenocarpic berries,and the rela...Polyamines(PAs)and ethylene are involved in the modulation of plant growth and development.However,their roles in fruit-set,especially in exogenous gibberellin(GA_(3))-induced grape parthenocarpic berries,and the related competitive action mode are poorly understood.For this,we,here performed their content determination,bioinformatics and expression pattern analysis of genes to identify the key ones in the competitive network of polyamines metabolic and ethylene biosynthesis(PMEB)pathways.The content of putrescine(Put)significantly increased;while 1-aminocyclopropanecarboxylic acid(ACC)sharply decreased during the fruit-set process of GA_(3)-induced grape parthenocarpic seedless berries.Totally,twenty-five genes in PMEB pathways,including 20 polyamines metabolic(PM)genes and 5 ethylene biosynthesis(EB)ones were identified in grape,of which 8 PM and 2 EB genes possessed the motifs responsive to phytohormone GA.The expression levels of most PMEB genes kept changing during grape fruit-set generating a competitive action mode of GA_(3)-mediated two metabolic fluxes toward PAs and ethylene synthesis.Exogenous GA_(3)might enhance grape fruit-set of parthenocarpic berries via up-regulation of VvSAMS4,VvSAMDC1/2,VvODC1,VvSPDS1,and VvPAO1 to promote PAs accumulation,whereby repressing the ethylene synthesis by down-regulation of VvACS1 and VvACO_(2).Our findings provide novel insights into GA_(3)-mediated competitive inhibition of ethylene by PAs to promote the fruit-set of parthenocarpic berries in grape,which has important implications for molecular breeding of seedless grape with high fruit-setting rate.展开更多
Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that sy...Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that synergizes CO_(2)-H_(2)O co-electrolysis(producing CO/O_(2) feeds)with oxidative double carbonylation of ethylene/acetylene to synthesize CO_(2)-derived C_(4) diesters(dimethyl succinate,fumarate,and maleate).A group of versatile building blocks for manufacturing plasticizers,biodegradable polymers,and pharmaceutical intermediates.Remarkably,CO_(2) exhibits dual functionality:serving simultaneously as a CO/O_(2) source and an explosion suppressant during the oxidative carbonylation process.We systematically investigated the explosion-suppressing efficacy of CO_(2) in flammable gas mixtures(CO/O_(2),C_(2)H_(4)/CO/O_(2),and C_(2)H_(2)/CO/O_(2))across varying concentrations.Notably,the mixed gas stream from CO_(2)/H_(2)O co-electrolysis at an industrial-scale current densities of 400 mA/cm^(2),enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety.Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis.This study establishes not only a safe protocol for oxidative carbonylation processes,but also opens an innovative pathway for sustainable CO_(2) valorization,including CO surrogate and explosion suppressant.展开更多
Tomato(Solanum lycopersicum)has become a model for the study of fleshy fruits.Comprehending the regulatory mechanisms of fleshy fruit ripening is important.Transcription factors(TFs),hormones,and epigenetic regulation...Tomato(Solanum lycopersicum)has become a model for the study of fleshy fruits.Comprehending the regulatory mechanisms of fleshy fruit ripening is important.Transcription factors(TFs),hormones,and epigenetic regulation mainly regulate tomato fruit ripening,and the initiation of ripening requires ethylene and ripening-related TFs,such as NAC,MADS-box,RIN,GH3,HD-ZIP,and basic helix-loop-helix.In this review,we summarize recent research progress on these TFs in the regulation of tomato fruit ripening and highlight the crosstalk mechanisms of ethylene and ripening-related TFs.By affecting ethylene synthesis and signaling,TFs regulate softening and color changes in tomato fruits,thereby influencing fruit quality.Our review contributes to a systematic understanding of the regulatory mechanisms of tomato fruit ripening and provides a basis for developing or modeling complex ripening regulatory networks.展开更多
In climacteric fruits,the role of ethylene in promoting ripening process and its molecular regulatory mechanisms have been well elucidated.However,research into ethylene's roles in non-climacteric fruits has only ...In climacteric fruits,the role of ethylene in promoting ripening process and its molecular regulatory mechanisms have been well elucidated.However,research into ethylene's roles in non-climacteric fruits has only advanced in recent years,largely because these fruits produce much less ethylene than climacteric fruits.Consequently,reports on its molecular regulatory involvement are still limited.Grape(Vitis vinifera L.),one of the most economically valuable fruits,is regarded as a classical non-climacteric fruit.In this study,an enzyme participating in the last step of ethylene biosynthesis,VvACO1,has been identified as a key enzyme controlling ethylene release in grape fruits(Vitis vinifera‘Jingyan’and‘Red Balado’)using correlation analysis and enzymatic experiments.The transcriptional regulation of VvACO1 was investigated by integrating multiple methods such as DNA pull-down assays,co-expression analysis,dual luciferase reporting system,yeast one-hybrid assays,and transgenic experiments.Our findings revealed that the upregulation of VvACO1 in grape fruits was primarily caused by the removal of transcriptional inhibition.Remarkably,seven transcription factors(TFs)were identified as inhibitors of VvACO1,including VvHY5 from bZIP family,VvWIP2 from C2H2 family,VvBLH1 from Homeobox family,VvAG1 and VvCMB1 from MADS-box family,VvASIL1 and VvASIL2 from Trihelix family.These seven TFs were located in nuclei and exhibited transcriptional inhibition activity.Notably,VvAG1 and VvASIL2 could inhibit VvACO1 expression when overexpressed in grape leaves.Our findings provided theoretical clues for differences of ethylene release regulation between climacteric and non-climacteric fruits,also the identified seven TFs could be potential targets for grape molecular breeding.展开更多
Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most ...Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most autophagy-related genes(ATGs)were up-regulated during tomato(Solanum lycopersicum L.)fruit ripening.By using mutants of different autophagy pathway genes(ATG6,ATG10,ATG18a),we revealed that the deficiency of autophagy delayed the ripening of fruit.Compared with wild-type(WT),the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening.We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT,while the content of organic acids showed the opposite trend.Additionally,the negative regulator of ethylene production,APETALA2a(AP2a),interacted with ATG8 through a specific ATG8-interacting motif(AIM)and could be degraded through the autophagy pathway.These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments,sugars and organic acids in tomato.展开更多
Chemical looping oxidative dehydrogenation(CL‐ODH)is a promising novel method to convert ethane into higher value‐added ethylene.In this study,perovskite‐type Co_(2)O_(3)/LaCoO_(3) was prepared by the one‐step cit...Chemical looping oxidative dehydrogenation(CL‐ODH)is a promising novel method to convert ethane into higher value‐added ethylene.In this study,perovskite‐type Co_(2)O_(3)/LaCoO_(3) was prepared by the one‐step citric acid‐gel method and applied as an oxygen carrier in the CL‐ODH process of ethane to ethylene;moreover,the effects of CuO,ZnO,and MgO as additives were investigated.The properties of the oxygen carriers were characterized using XRD,BET,XPS,H_(2)‐TPR,O_(2)‐TPD,and EPR.Characterization results showed that the addition of additives into Co_(2)O_(3)/LaCoO_(3) increased the amounts of surface chemisorbed oxygen and lattice oxygen.Co_(2)O_(3)/LaCoO_(3) had a strong ability to absorb and release oxygen after adding CuO,ZnO,and MgO,respectively.The performances of the oxygen carriers for CL‐ODH of ethane to ethylene were studied at a reaction temperature of 650℃,atmospheric pressure,and GHSV of 15,000 mL/g·h in eight redox cycles.All the oxygen carriers had 100%ethane conversion,and ZnO‐Co_(2)O_(3)/LaCoO_(3) exhibited the best ethylene selectivity of more than 70%in all the oxygen carriers.It was confirmed that lattice oxygen was mainly responsible for the selectivity of ethylene,and oxygen vacancies were conducive to the migration of lattice oxygen.Most of Zn^(2+) entered into the bulk phase of Co_(2)O_(3)/LaCoO_(3),and formed lots of oxygen vacancies.展开更多
Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephth...Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephthalate(PET)due to its enhanced material properties.However,the fabrication of PEF with stable and desirable properties is still a challenge,largely due to the impurities in FDCA.In this study,a highly efficient purification strategy for FDCA was proposed,utilizing a dioxane/H_(2)O binary solvent system for effective crystallization.Furthermore,PEFs were synthesized from FDCA with varying impurity and the effects of these impurities were systematically characterized.The results revealed that impurities in FDCA could result in PEFs with relatively poor thermal properties.This study provides crucial insights for the impact of impurities on PEF properties and FDCA purification.展开更多
Electrocatalytic oxidation of surplus ethylene glycol(EG)to high-value glycolic acid(GA)represents a promising approach for sustainable resource utilization,though critical challenges persist in developing durable ele...Electrocatalytic oxidation of surplus ethylene glycol(EG)to high-value glycolic acid(GA)represents a promising approach for sustainable resource utilization,though critical challenges persist in developing durable electrocatalysts and achieving effective recovery of the free acid product from its salt derivatives in alkaline electrolytes.In this work,a PdNi/NF catalyst was rationally synthesized via a one-step electrodeposition method.Systematic characterization revealed that the electron transfer from Ni to Pd modulates *OH adsorption to accelerate EG oxidation reaction(EGOR)while preventing Pd deactivation through oxidation.The optimized system demonstrated exceptional alkaline performance with a glycolic acid Faraday efficiencyof 95%and a current density of 666 mA·cm^(-2).When implemented in an asymmetric EGOR||HER flowcell configuration where only the cathodic electrolyte contains alkaline,the system demonstrated exceptional operational stability by sustaining 70 mA·cm^(-2) current density at a low cell voltage of 0.9 V in neutral media for over 100 h,with product glycolic acid requiring no further acidification.This investigation provides a practical framework for designing efficientelectrocatalytic systems that simplifiesproduct separation steps.展开更多
In direct ethylene glycol fuel cells,advanced anodic electrocatalysts are urgently required to achieve high energy efficiency and optimal fuel utilization for complete ethylene glycol electrooxidation.In this work,bim...In direct ethylene glycol fuel cells,advanced anodic electrocatalysts are urgently required to achieve high energy efficiency and optimal fuel utilization for complete ethylene glycol electrooxidation.In this work,bimetallic PtRh nanodendrites(PtRh NDs)with a three-dimensionally self-supporting structure,abundant(100)crystal facets,and numerous Pt/Rh active sites are synthesized using a simple wet chemical reduction method.The as-synthesized PtRh NDs exhibit outstanding electrocatalytic activity and remarkable selectivity for the ethylene glycol oxidation reaction(EGOR)in alkaline media,significantly enhancing the utilization of ethylene glycol fuel in fuel cells.Theoretical calculations demonstrate that the exposure of(100)crystal faces and the incorporation of Rh atoms play crucial roles in improving the activity and selectivity of EGOR.The present work not only provides an effective method for the synthesis of PtRh NDs with rich(100)crystal faces but also provides new insights into the synergistic effects between the crystal faces and the components in the electrocata lytic process.展开更多
Ethylene(C_(2)H_(4))is a core raw material for the petrochemical industry.It is of economic and environmental significance to use C_(2)H_(6)as the fuel and proton-conducting solid oxide fuel cells(P-SOFC)as the reacto...Ethylene(C_(2)H_(4))is a core raw material for the petrochemical industry.It is of economic and environmental significance to use C_(2)H_(6)as the fuel and proton-conducting solid oxide fuel cells(P-SOFC)as the reactor to co-generate electricity and C_(2)H_(4).However,the large-sized Ni particles in the conventional Nicermet anode directly crack C_(2)H_(6);and oxide materials with a mild capability of breaking C-C bonds are generally limited to electrolyte-supported structures with high ohmic impedance.This research for the first time constructs an anode-supported cell using BZCY as the porous scaffold and impregnated double perovskite(PrBa)_(0.95)(Fe_(0.8)Ni_(0.2))_(1.8)Mo_(0.2)O_(6-δ)(PBFNM0.2)as the anode electrocatalysis.FeNi3 nanoparticles exsolve from PBFNM0.2 in H_(2) and uniformly distribute on the surface of perovskite substrate,acting as an active component for C_(2)H_(6)dehydrogenation and electrochemical performance enhancement.The cell with 30 wt%PBFNM0.2 impregnated anode showing a high power density of 508 and 386mW/cm^(2) with H_(2) and C_(2)H_(6)fuels,respectively;high C_(2)H_(6)conversion of 50.9%,C_(2)H_(4)selectivity of 92.1%,and C_(2)H_(4)yield of 46.9%are achieved at 750℃and 700mA/cm^(2),which outperforms all previously electrolyte-supported cells for co-generated electricity and ethylene.Moreover,the cell demonstrated excellent recoverability throughout three dehydrogenation-regeneration cycles.This work provides a practical way with broad application potential to create a novel anode-supported cell efficiently realizing the co-generation of electricity and C_(2)H_(4)from C_(2)H_(6).展开更多
Ambient temperature affects the occurrence and prevalence of plant disease.Most bacterial diseases are damaging at high temperatures.However,kiwifruit bacterial canker caused by Pseudomonas syringae pv.actinidiae(Psa)...Ambient temperature affects the occurrence and prevalence of plant disease.Most bacterial diseases are damaging at high temperatures.However,kiwifruit bacterial canker caused by Pseudomonas syringae pv.actinidiae(Psa)has been found to be prevalent at relatively cool temperatures,and it is unclear how ambient temperature affects the development of kiwifruit bacterial canker.In this study,basal resistance to Psa was suppressed in kiwifruit at cool growth temperature(16℃)compared with at normal temperature(24℃).In addition,RNA sequence analysis and ethylene content assessment indicated that ethylene modulated kiwifruit resistance to Psa at normal growth temperature and that cool temperature inhibited ethylene accumulation and Psa-induced activation of the ethylene signaling pathway in kiwifruit.Virusmediated silencing of the kiwifruit ethylene signaling gene AcEIN2 suppressed kiwifruit resistance to Psa at normal growth temperature.Exogenous application of ethylene inhibitor 1-methylcyclopropene eliminated the difference in kiwifruit resistance to Psa at 16 and 24℃.Exogenous application of ethylene analogues ethephon induced resistance to Psa in kiwifruit.In conclusion,cool temperatures impair basal resistance to Psa by reducing the activation of ethylene biosynthesis and signaling in kiwifruit.The results provide clues for new strategies to control plant diseases in a context of global environmental change.展开更多
The small punch test technique facilitates the convenient acquisition of the mechanical properties of in-service equipment materials and the assessment of their remaining service life through sampling.However,the weld...The small punch test technique facilitates the convenient acquisition of the mechanical properties of in-service equipment materials and the assessment of their remaining service life through sampling.However,the weldability of components with thin walls after small punch sampling,such as ethylene cracking furnace tubes,requires further investigation.Therefore,the weldability of in-service ethylene cracking furnace tubes following small punch sampling was investigated through nondestructive testing,microstructural characterization,and mechanical testing.Additionally,the impact of small punch sampling size and residual stress on the creep performance of the specimens was studied using an improved ductility exhaustion model.The results indicate that both the surface and interior of the weld repair areas on new furnace tubes and service-exposed furnace tubes after small-punch sampling are defect-free,exhibiting good weld quality.The strength of the specimens after weld repair was higher than that before sampling,whereas toughness decreased.Weld repair following small punch sampling of furnace tubes is both feasible and necessary.Furthermore,a linear relationship was observed between specimen thickness,diameter,and creep fracture time.The residual stress of welding affects the creep performance of the specimen under different stresses.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52473338)the National Natural Science Foundation of China(Nos.52173004 and 51873055)+3 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0540000)Advanced Materials-National Science and Technology Major Project(No.2025ZD0614000)Hebei Natural Science Foundation(No.E2022202015)Anhui Province Science and Technology Innovation Tackling Key Project(No.202423i08050025)。
文摘Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.
基金financial support from the National Natural Science Foundation of China(Nos.22401274,U23B6011)the Jilin Provincial Science and Technology Department Program(No.20250102070JC)。
文摘Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3700300)the National Natural Science Foundation of China(Nos.52573017 and U21B2093)+1 种基金Key Research and Development Program of Ningbo(No.2022Z200)the Zhejiang Provincial Natural Science Foundation(No.LY23E030005)。
文摘Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardant strategies often compromise their mechanical properties,hindering their practical applications.Herein,a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)-based comonomer(DDP)was used to synthesize flame-retardant poly(ethylene furandicarboxylate-co-phosphaphenanthrene)(PEFDn).The covalent integration of DDP confers intrinsic flame retardancy,avoiding the plasticization and migration issues associated with additive-type systems.Upon thermal decomposition,the DOPO-derived moieties release phosphoric acid and radical scavengers,promoting char formation and suppressing flame propagation.Furthermore,density functional theory(DFT)calculations combined with non-covalent interaction(NCI)analysis revealed that DOPO dimer molecules adopt a stable parallel-displaced π-π stacking configu ration,potentially facilitating microphase separation and enhancing the energy dissipation capability.PEFD_(10)achieves a UL-94 V-0 rating while simultaneously increasing impact toughness from 1.5 kJ/m^(2) to 14.7 kJ/m^(2).Im portantly,PEFDn maintained acceptable oxygen-barrier properties.PEFD10 also exhibited high transparency and UV-shielding performance.The combination of intrinsic flame safety,im pact-toughness resistance,UV shielding,and an oxygen barrier ensures reliable protection of electrical components and long-term operational stability.The integration of multiple critical properties within a single bio-based material represents a novel approach fo r enabling sustainable polymer solutions for high-pe rformance electrical applications.
文摘Although the efficiency of poly(ethylene terephthalate)(PET)degradation has been successfully improved by depolymerase engineering,mostly by using Goodfellow-PET(gf-PET)as a substrate,efforts to degrade unpretreated PET materials with high crystallinity remain insufficient.Here,we endeavored to improve the degradation capability of a WCCG mutant of leaf-branch compost cutinase(LCC)on a unpretreated PET substrate(crystallinity>40%)by employing iterative saturation mutagenesis.Using this method,we developed a high-throughput screening strategy appropriate for unpretreated substrates.Through extensive screening of residues around the substrate-binding groove,two variants,WCCG-sup1 and WCCG-sup2,showed good depolymerization capabilities with both high-(42%)and low-crystallinity(9%)substrates.The WCCG-sup1 variant completely depolymerized a commercial unpretreated PET product in 36 h at 72℃.In addition to enzyme thermostability and catalytic efficiency,the adsorption of enzymes onto substrates plays an important role in PET degradation.This study provides valuable insights into the structure-function relationship of LCC.
文摘Ethylene glycol(EG)is a biomass derivative of polyethylene terephthalate(PET),and its electrocatalytic conversion into high-value chemicals has sparked widespread interest.This study reviews the most recent research development in electrocatalysis-based EG to glycolic acid(GA)conversion.Firstly,the strategies and research results of modulating the electronic structure of catalysts for efficient selective GA production from EG are reviewed.Second,by reviewing the data of in-situ Fourier transform infrared spectroscopy and in-situ electrochemically attenuated total reflection surface enhanced infrared absorption spectroscopy,the reaction pathway and catalytic mechanism of EG partial oxidation to GA were clarified.Finally,the design and regulation of catalysts for selective oxidation of EG by electrocatalysis in the future are prospected.
基金financially supported by the Maoming Science and Technology Bureau(No.2022DZXHT007)。
文摘The synthesis of polyurethanes(PUs)from the reaction of low molecular weight poly(ethylene carbonate)diol(PECD)is rarely investigated.This work reports a novel PU with excellent mechanical properties from the solution polymerization of 4,4-diphenylmethane diisocyanate(MDI)with PECD that was derived from the copolymerization of carbon dioxide(CO_(2))and ethylene oxide(EO).The tensile strength,the elongation at break and 300%constant tensile strength of the PECD-PU were up to 66±2 MPa,880%±50%and 13 MPa,respectively,higher than the control PUs from the reaction of MDI with commercial polyethers or polyesters.The PECD-PU with high CO_(2) carbonate content exhibited good solvent resistance and chemical stability.Of importance,the mechanical properties and chemical resistance of PECD-PU were significantly enhanced with the increasing content of CO_(2),i.e.,the carbonate unit in PECD.This work provides comprehensive properties of PECD-derived PUs,indicating that PECD is a competitive precursor for the preparation of PU and has broad application prospects.
基金financially supported by the National Natural Science Foundation of China(No.21172269)the Fundamental Research Funds for the Central Universities,SouthCentral Minzu University(No.CZH24005)。
文摘Binuclear complexes have attracted extensive attention in fields such as catalysis because of their likely bimetallic synergistic effect;however,the mechanism and factors influencing this synergism remain unclear.In this work,six bis-β-ketoimine binuclear titanium complexes4a-4f containing different alkylthio sidearms and configurations were synthesized and characterized by nuclear magnetic resonance hydrogen spectrum(~1H-NMR),nuclear magnetic resonance carbon spectrum(^(13)C-NMR),Fourier transform infrared spectrum(FTIR),and elemental analysis.The intermetallic distances of isomeric complexes 4a,4d,4e and 4f determined through density functional theory(DFT)optimization were in the order 4a<4d<4e<4f and were found to significantly influence the catalytic performance for ethylene(co)polymerization.These complexes could efficiently catalyze ethylene polymerization and ethylene/1-hexene or ethylene/1-octene copolymerization with high activity to produce highmolecular-weight ethylene homo-and co-polymers.Among the three binuclear titanium complexes 4a-4c with similar structures but different lengths of alkylthio sidearms,complex 4a,which contained the shortest methylthio sidearm,exhibited the highest activity for ethylene polymerization and copolymerization with 1-hexene or 1-octene.Additionally,for ethylene/1-hexene or ethylene/1-octene copolymerization,it showed the highest comonomer incorporation compared with propylthio(4b)and octylthio(4c)derivatives because of the smaller steric hindrance of the methyl group in 4a and the more open coordination space for vinyl monomers.Furthermore,among the isomeric complexes 4a,4d,4e and4f,complex 4a with the shortest bimetallic distance also exhibited the highest activity towards ethylene(co)polymerization,and the highest 1-hexene or 1-octene incorporation in comparison with its regioisomeric counterparts 4d,4e and p-phenyl-bridged analog 4f,owing to a more appropriate bimetallic distance that is conducive to a synergistic effect.
基金supported by the National Natural Science Foundation of China(No.22278041)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K78)+1 种基金Jiangsu Province Key Laboratory of Fine Petrochemical Engineering(No.KF2107)the Advanced Catalysis and Green Manufacturing Collab-orative Innovation Center(No.ACGM2022-10-07)。
文摘Herein,a series of manganese oxide catalysts with different valences(Mn_(3)O_(4),Mn_(2)O_(3),and MnO_(2))were designed and synthesized for the synthesis of ethylene urea(EU)from ethylenediamine(EDA)and carbon dioxide(CO_(2)).With a maximal EDA conversion of 82%and EU selectivity of 99%at 160℃ for 2 h,Mn_(2)O_(3) catalysts had the best catalytic activity among them,which was superior to the reported catalysts.In the following order:Mn_(2)O_(3)>MnO_(2)>Mn_(3)O_(4),the catalytic activity for the synthesis of EU from CO_(2) and EDA decreased.Further characterization showed the Mn_(2)O_(3) catalyst possessed a greater Mn^(3+)/Mn4+ratio and more surface oxygen vacancies than the MnO_(2) and Mn_(3)O_(4),which improved its capacity to adsorb and activate CO_(2) and EDA.After four recycling runs,the EDA conversion slightly declined from 82%to 56%on Mn_(2)O_(3) catalyst,while no obvious change in EU selectivity was observed.The loss of surface Ov contents and Mn^(3+)proportion were concluded as main reasons for the decrease in catalytic activity over Mn_(2)O_(3) catalyst.This work demonstrated a metal oxide catalyst that was efficient in producing EU from CO_(2) and EDA.
基金supported by grants from Jiangsu province seed industry revitalization of the leading project(JBGS[2021]086)the National Natural Science Funds(31972373,32272647,32202433)+1 种基金the Provincial Natural Science Foundation of Jiangsu(BK20200541)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD),and Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX22_0754,SJCX23-0209).
文摘Polyamines(PAs)and ethylene are involved in the modulation of plant growth and development.However,their roles in fruit-set,especially in exogenous gibberellin(GA_(3))-induced grape parthenocarpic berries,and the related competitive action mode are poorly understood.For this,we,here performed their content determination,bioinformatics and expression pattern analysis of genes to identify the key ones in the competitive network of polyamines metabolic and ethylene biosynthesis(PMEB)pathways.The content of putrescine(Put)significantly increased;while 1-aminocyclopropanecarboxylic acid(ACC)sharply decreased during the fruit-set process of GA_(3)-induced grape parthenocarpic seedless berries.Totally,twenty-five genes in PMEB pathways,including 20 polyamines metabolic(PM)genes and 5 ethylene biosynthesis(EB)ones were identified in grape,of which 8 PM and 2 EB genes possessed the motifs responsive to phytohormone GA.The expression levels of most PMEB genes kept changing during grape fruit-set generating a competitive action mode of GA_(3)-mediated two metabolic fluxes toward PAs and ethylene synthesis.Exogenous GA_(3)might enhance grape fruit-set of parthenocarpic berries via up-regulation of VvSAMS4,VvSAMDC1/2,VvODC1,VvSPDS1,and VvPAO1 to promote PAs accumulation,whereby repressing the ethylene synthesis by down-regulation of VvACS1 and VvACO_(2).Our findings provide novel insights into GA_(3)-mediated competitive inhibition of ethylene by PAs to promote the fruit-set of parthenocarpic berries in grape,which has important implications for molecular breeding of seedless grape with high fruit-setting rate.
文摘Upgrading carbon dioxide(CO_(2))into value-added bulk chemicals offers a dual-benefit strategy for the carbon neutrality and circular carbon economy.Herein,we develop an integrated CO_(2) valorization strategy that synergizes CO_(2)-H_(2)O co-electrolysis(producing CO/O_(2) feeds)with oxidative double carbonylation of ethylene/acetylene to synthesize CO_(2)-derived C_(4) diesters(dimethyl succinate,fumarate,and maleate).A group of versatile building blocks for manufacturing plasticizers,biodegradable polymers,and pharmaceutical intermediates.Remarkably,CO_(2) exhibits dual functionality:serving simultaneously as a CO/O_(2) source and an explosion suppressant during the oxidative carbonylation process.We systematically investigated the explosion-suppressing efficacy of CO_(2) in flammable gas mixtures(CO/O_(2),C_(2)H_(4)/CO/O_(2),and C_(2)H_(2)/CO/O_(2))across varying concentrations.Notably,the mixed gas stream from CO_(2)/H_(2)O co-electrolysis at an industrial-scale current densities of 400 mA/cm^(2),enabling direct utilization in oxidative double carbonylation reactions with exceptional compatibility and inherent safety.Extended applications were demonstrated through substrate scope expansion and gram-scale synthesis.This study establishes not only a safe protocol for oxidative carbonylation processes,but also opens an innovative pathway for sustainable CO_(2) valorization,including CO surrogate and explosion suppressant.
基金supported by the National Natural Science Foundation of China(Grant Nos.32360743,32072559,31860568,31560563 and 31160398)the National Key Research and Development Program(Grant No.2018YFD1000800).
文摘Tomato(Solanum lycopersicum)has become a model for the study of fleshy fruits.Comprehending the regulatory mechanisms of fleshy fruit ripening is important.Transcription factors(TFs),hormones,and epigenetic regulation mainly regulate tomato fruit ripening,and the initiation of ripening requires ethylene and ripening-related TFs,such as NAC,MADS-box,RIN,GH3,HD-ZIP,and basic helix-loop-helix.In this review,we summarize recent research progress on these TFs in the regulation of tomato fruit ripening and highlight the crosstalk mechanisms of ethylene and ripening-related TFs.By affecting ethylene synthesis and signaling,TFs regulate softening and color changes in tomato fruits,thereby influencing fruit quality.Our review contributes to a systematic understanding of the regulatory mechanisms of tomato fruit ripening and provides a basis for developing or modeling complex ripening regulatory networks.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.32025032 and 32202415)the Agricultural Breeding Project of Ningxia Hui Autonomous Region(Grant No.NXNYYZ20210104)the National Key Research and Development Program of China(Grant No.2022YFE0116400).
文摘In climacteric fruits,the role of ethylene in promoting ripening process and its molecular regulatory mechanisms have been well elucidated.However,research into ethylene's roles in non-climacteric fruits has only advanced in recent years,largely because these fruits produce much less ethylene than climacteric fruits.Consequently,reports on its molecular regulatory involvement are still limited.Grape(Vitis vinifera L.),one of the most economically valuable fruits,is regarded as a classical non-climacteric fruit.In this study,an enzyme participating in the last step of ethylene biosynthesis,VvACO1,has been identified as a key enzyme controlling ethylene release in grape fruits(Vitis vinifera‘Jingyan’and‘Red Balado’)using correlation analysis and enzymatic experiments.The transcriptional regulation of VvACO1 was investigated by integrating multiple methods such as DNA pull-down assays,co-expression analysis,dual luciferase reporting system,yeast one-hybrid assays,and transgenic experiments.Our findings revealed that the upregulation of VvACO1 in grape fruits was primarily caused by the removal of transcriptional inhibition.Remarkably,seven transcription factors(TFs)were identified as inhibitors of VvACO1,including VvHY5 from bZIP family,VvWIP2 from C2H2 family,VvBLH1 from Homeobox family,VvAG1 and VvCMB1 from MADS-box family,VvASIL1 and VvASIL2 from Trihelix family.These seven TFs were located in nuclei and exhibited transcriptional inhibition activity.Notably,VvAG1 and VvASIL2 could inhibit VvACO1 expression when overexpressed in grape leaves.Our findings provided theoretical clues for differences of ethylene release regulation between climacteric and non-climacteric fruits,also the identified seven TFs could be potential targets for grape molecular breeding.
基金supported by the National Natural Science Foundation of China(Grant Nos.32302642,32272790)the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(Grant No.SN-ZJU-SIAS-0011)+1 种基金Collaborative Promotion Program of Zhejiang Provincial Agricultural Technology of China(Grant No.2023ZDXT05)the Fundamental Research Funds for the Central Universities(Grant No.226-2022-00122).
文摘Autophagy is a universal cellular process in eukaryotes that plays a critical role in plant growth and stress response.However,the role of autophagy in fruit ripening is largely unknown.Here,we demonstrated that most autophagy-related genes(ATGs)were up-regulated during tomato(Solanum lycopersicum L.)fruit ripening.By using mutants of different autophagy pathway genes(ATG6,ATG10,ATG18a),we revealed that the deficiency of autophagy delayed the ripening of fruit.Compared with wild-type(WT),the production of ethylene was significantly reduced and the accumulation of lycopene was delayed in atg mutants during fruit ripening.We also observed the contents of glucose and fructose were both significantly decreased in atg mutants compared with WT,while the content of organic acids showed the opposite trend.Additionally,the negative regulator of ethylene production,APETALA2a(AP2a),interacted with ATG8 through a specific ATG8-interacting motif(AIM)and could be degraded through the autophagy pathway.These results demonstrate that autophagy plays a critical role in fruit ripening by regulating ethylene production and the accumulation of pigments,sugars and organic acids in tomato.
基金The funding of this submission came from our laboratory sponsored by the college
文摘Chemical looping oxidative dehydrogenation(CL‐ODH)is a promising novel method to convert ethane into higher value‐added ethylene.In this study,perovskite‐type Co_(2)O_(3)/LaCoO_(3) was prepared by the one‐step citric acid‐gel method and applied as an oxygen carrier in the CL‐ODH process of ethane to ethylene;moreover,the effects of CuO,ZnO,and MgO as additives were investigated.The properties of the oxygen carriers were characterized using XRD,BET,XPS,H_(2)‐TPR,O_(2)‐TPD,and EPR.Characterization results showed that the addition of additives into Co_(2)O_(3)/LaCoO_(3) increased the amounts of surface chemisorbed oxygen and lattice oxygen.Co_(2)O_(3)/LaCoO_(3) had a strong ability to absorb and release oxygen after adding CuO,ZnO,and MgO,respectively.The performances of the oxygen carriers for CL‐ODH of ethane to ethylene were studied at a reaction temperature of 650℃,atmospheric pressure,and GHSV of 15,000 mL/g·h in eight redox cycles.All the oxygen carriers had 100%ethane conversion,and ZnO‐Co_(2)O_(3)/LaCoO_(3) exhibited the best ethylene selectivity of more than 70%in all the oxygen carriers.It was confirmed that lattice oxygen was mainly responsible for the selectivity of ethylene,and oxygen vacancies were conducive to the migration of lattice oxygen.Most of Zn^(2+) entered into the bulk phase of Co_(2)O_(3)/LaCoO_(3),and formed lots of oxygen vacancies.
基金supported by the National Natural Science Foundation of China(22378338,U22A20421)the Project for Science and Technology Plan of Fujian Province of China(2024H4007)。
文摘Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephthalate(PET)due to its enhanced material properties.However,the fabrication of PEF with stable and desirable properties is still a challenge,largely due to the impurities in FDCA.In this study,a highly efficient purification strategy for FDCA was proposed,utilizing a dioxane/H_(2)O binary solvent system for effective crystallization.Furthermore,PEFs were synthesized from FDCA with varying impurity and the effects of these impurities were systematically characterized.The results revealed that impurities in FDCA could result in PEFs with relatively poor thermal properties.This study provides crucial insights for the impact of impurities on PEF properties and FDCA purification.
基金financially supported by the National Key Research and Development Program of China(2022YFA1504200)the National Natural Science Foundation of China(22178033 and 22090030)the Fundamental Research Funds for the Central Universities(2024CDJXY010).
文摘Electrocatalytic oxidation of surplus ethylene glycol(EG)to high-value glycolic acid(GA)represents a promising approach for sustainable resource utilization,though critical challenges persist in developing durable electrocatalysts and achieving effective recovery of the free acid product from its salt derivatives in alkaline electrolytes.In this work,a PdNi/NF catalyst was rationally synthesized via a one-step electrodeposition method.Systematic characterization revealed that the electron transfer from Ni to Pd modulates *OH adsorption to accelerate EG oxidation reaction(EGOR)while preventing Pd deactivation through oxidation.The optimized system demonstrated exceptional alkaline performance with a glycolic acid Faraday efficiencyof 95%and a current density of 666 mA·cm^(-2).When implemented in an asymmetric EGOR||HER flowcell configuration where only the cathodic electrolyte contains alkaline,the system demonstrated exceptional operational stability by sustaining 70 mA·cm^(-2) current density at a low cell voltage of 0.9 V in neutral media for over 100 h,with product glycolic acid requiring no further acidification.This investigation provides a practical framework for designing efficientelectrocatalytic systems that simplifiesproduct separation steps.
基金sponsored by the National Natural Science Foundation of China(22272103)the Programs of Science and Technology of Suzhou in China(ZXL2021448 and SYG202137)+4 种基金Science and Technology Innovation Team of Shaanxi Province(2022TD-35 and 2023-CX-TD-27)the Young Scientist Initiative Project of School of Materials Science and Engineering at Shaanxi Normal University(2024YSIP-MSE-SNNU004)the Fundamental Research Funds for the Central Universities(GK202505036)the Technology Innovation Leading Program of Shaanxi in ChinaSanqin Scholars Innovation Teams in Shaanxi Province in China。
文摘In direct ethylene glycol fuel cells,advanced anodic electrocatalysts are urgently required to achieve high energy efficiency and optimal fuel utilization for complete ethylene glycol electrooxidation.In this work,bimetallic PtRh nanodendrites(PtRh NDs)with a three-dimensionally self-supporting structure,abundant(100)crystal facets,and numerous Pt/Rh active sites are synthesized using a simple wet chemical reduction method.The as-synthesized PtRh NDs exhibit outstanding electrocatalytic activity and remarkable selectivity for the ethylene glycol oxidation reaction(EGOR)in alkaline media,significantly enhancing the utilization of ethylene glycol fuel in fuel cells.Theoretical calculations demonstrate that the exposure of(100)crystal faces and the incorporation of Rh atoms play crucial roles in improving the activity and selectivity of EGOR.The present work not only provides an effective method for the synthesis of PtRh NDs with rich(100)crystal faces but also provides new insights into the synergistic effects between the crystal faces and the components in the electrocata lytic process.
基金financially supported by the National Natural Science Foundation of China(Nos.52072134,52272205)Hubei Province(Nos.2021BCA149,2021CFA072,2022BAA087)the special fund for Science and Technology Innovation Teams of Shanxi Province(No.202304051001007)。
文摘Ethylene(C_(2)H_(4))is a core raw material for the petrochemical industry.It is of economic and environmental significance to use C_(2)H_(6)as the fuel and proton-conducting solid oxide fuel cells(P-SOFC)as the reactor to co-generate electricity and C_(2)H_(4).However,the large-sized Ni particles in the conventional Nicermet anode directly crack C_(2)H_(6);and oxide materials with a mild capability of breaking C-C bonds are generally limited to electrolyte-supported structures with high ohmic impedance.This research for the first time constructs an anode-supported cell using BZCY as the porous scaffold and impregnated double perovskite(PrBa)_(0.95)(Fe_(0.8)Ni_(0.2))_(1.8)Mo_(0.2)O_(6-δ)(PBFNM0.2)as the anode electrocatalysis.FeNi3 nanoparticles exsolve from PBFNM0.2 in H_(2) and uniformly distribute on the surface of perovskite substrate,acting as an active component for C_(2)H_(6)dehydrogenation and electrochemical performance enhancement.The cell with 30 wt%PBFNM0.2 impregnated anode showing a high power density of 508 and 386mW/cm^(2) with H_(2) and C_(2)H_(6)fuels,respectively;high C_(2)H_(6)conversion of 50.9%,C_(2)H_(4)selectivity of 92.1%,and C_(2)H_(4)yield of 46.9%are achieved at 750℃and 700mA/cm^(2),which outperforms all previously electrolyte-supported cells for co-generated electricity and ethylene.Moreover,the cell demonstrated excellent recoverability throughout three dehydrogenation-regeneration cycles.This work provides a practical way with broad application potential to create a novel anode-supported cell efficiently realizing the co-generation of electricity and C_(2)H_(4)from C_(2)H_(6).
基金supported by grants from the National Key Research and Development Program of China(Grant No.2022YFD1400200)the Special Support Plan for High-Level Talent of Shaanxi Province。
文摘Ambient temperature affects the occurrence and prevalence of plant disease.Most bacterial diseases are damaging at high temperatures.However,kiwifruit bacterial canker caused by Pseudomonas syringae pv.actinidiae(Psa)has been found to be prevalent at relatively cool temperatures,and it is unclear how ambient temperature affects the development of kiwifruit bacterial canker.In this study,basal resistance to Psa was suppressed in kiwifruit at cool growth temperature(16℃)compared with at normal temperature(24℃).In addition,RNA sequence analysis and ethylene content assessment indicated that ethylene modulated kiwifruit resistance to Psa at normal growth temperature and that cool temperature inhibited ethylene accumulation and Psa-induced activation of the ethylene signaling pathway in kiwifruit.Virusmediated silencing of the kiwifruit ethylene signaling gene AcEIN2 suppressed kiwifruit resistance to Psa at normal growth temperature.Exogenous application of ethylene inhibitor 1-methylcyclopropene eliminated the difference in kiwifruit resistance to Psa at 16 and 24℃.Exogenous application of ethylene analogues ethephon induced resistance to Psa in kiwifruit.In conclusion,cool temperatures impair basal resistance to Psa by reducing the activation of ethylene biosynthesis and signaling in kiwifruit.The results provide clues for new strategies to control plant diseases in a context of global environmental change.
基金supports provided by the National Natural Science Foundation of China(No.52372330).
文摘The small punch test technique facilitates the convenient acquisition of the mechanical properties of in-service equipment materials and the assessment of their remaining service life through sampling.However,the weldability of components with thin walls after small punch sampling,such as ethylene cracking furnace tubes,requires further investigation.Therefore,the weldability of in-service ethylene cracking furnace tubes following small punch sampling was investigated through nondestructive testing,microstructural characterization,and mechanical testing.Additionally,the impact of small punch sampling size and residual stress on the creep performance of the specimens was studied using an improved ductility exhaustion model.The results indicate that both the surface and interior of the weld repair areas on new furnace tubes and service-exposed furnace tubes after small-punch sampling are defect-free,exhibiting good weld quality.The strength of the specimens after weld repair was higher than that before sampling,whereas toughness decreased.Weld repair following small punch sampling of furnace tubes is both feasible and necessary.Furthermore,a linear relationship was observed between specimen thickness,diameter,and creep fracture time.The residual stress of welding affects the creep performance of the specimen under different stresses.
