Boosting oxygen reduction activity and CO_(2) resistance on bismuth ferrite-based perovskite cathode for low-temperature solid oxide fuel cells below 600℃

Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical commercialization.Herein,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for LT-SOFCs.Sm doping can significantly enhance the electrocata lytic activity and chemical stability of cathode.At 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious degradation.The remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi level.Moreover,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) resistivity.This work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.

Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane

It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.

Enhancing performance of low-temperature processed CsPbI2Br all-inorganic perovskite solar cells using polyethylene oxide-modified TiO_(2)

CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.

Low-temperature chemistry in plasma-driven ammonia oxidative pyrolysis

Ammonia is gaining increasing attention as a green alternative fuel for achieving large-scale carbon emission reduction. Despite its potential technical prospects, the harsh ignition conditions and slow flame propagation speed of ammonia pose significant challenges to its application in engines. Non-equilibrium plasma has been identified as a promising method, but current research on plasma-enhanced ammonia combustion is limited and primarily focuses on ignition characteristics revealed by kinetic models. In this study, low-temperature and low-pressure chemistry in plasma-assisted ammonia oxidative pyrolysis is investigated by integrated studies of steady-state GC measurements and mathematical simulation. The detailed kinetic mechanism of NH_(3) decomposition in plasma-driven Ar/NH_(3) and Ar/NH_(3)/O_(2) mixtures has been developed. The numerical model has good agreements with the experimental measurements in NH_(3)/O_(2) consumption and N_(2)/H_(2) generation, which demonstrates the rationality of modelling. Based on the modelling results, species density profiles, path flux and sensitivity analysis for the key plasmaproduced species such as NH_(2), NH, H_(2), OH, H, O, O(^(1)D), O_(2)(a^(1)△_(g)), O_(2)(b^(1)∑_(g)^(+)), Ar^(*), H^(-), Ar^(+), NH_(3)^(+), O_(2)^(-) in the discharge and afterglow are analyzed in detail to illustrate the effectiveness of the active species on NH_(3) excitation and decomposition at low temperature and relatively higher E/N values. The results revealed that NH_(2), NH, H as well as H_(2) are primarily generated through the electron collision reactions e + NH_(3)→ e + NH_(2)+ H, e + NH_(3)→ e + NH + H_(2) and the excited-argon collision reaction Ar^(*) + NH_(3)+ H → Ar + NH_(2)+ 2H, which will then react with highly reactive oxidative species such as O_(2)^(*), O^(*), O, OH, and O_(2) to produce stable products of NOx and H_(2)O. NH_(3)→ NH is found a specific pathway for NH_(3) consumption with plasma assistance, which further highlights the enhanced kinetic effects.

Understanding the roles of Brønsted/Lewis acid sites on manganese oxide-zeolite hybrid catalysts for low-temperature NH_(3)-SCR

Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their subsequent reaction mechanism on acid sites is still unclear and requires investigation.In this study,the distribution of Brønsted/Lewis acid sites in the hybrid materials was precisely adjusted by introducing potassium ions,which not only selectively bind to Brønsted acid sites but also potentially affect the formation and diffusion of activated NO species.Systematic in situ diffuse reflectance infrared Fourier transform spectroscopy analyses coupled with selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)reaction demonstrate that the Lewis acid sites over MnO_(x)are more active for NO reduction but have lower selectivity to N_(2)than Brønsted acids sites.Brønsted acid sites primarily produce N_(2),whereas Lewis acid sites primarily produce N_(2)O,contributing to unfavorable N_(2)selectivity.The Brønsted acid sites present in Y zeolite,which are stronger than those on MnO_(x),accelerate the NH_(3)-SCR reaction in which the nitrite/nitrate species diffused from the MnO_(x)particles rapidly convert into the N_(2).Therefore,it is important to design the catalyst so that the activated NO species formed in MnO_(x)diffuse to and are selectively decomposed on the Brønsted acid sites of H-Y zeolite rather than that of MnO_(x)particle.For the physically mixed H-MnO_(x)+H-Y sample,the abundant Brønsted/Lewis acid sites in H-MnO_(x)give rise to significant consumption of activated NO species before their inter-particle diffusion,thereby hindering the enhancement of the synergistic effects.Furthermore,we found that the intercalated K+in K-MnO_(x)has an unexpected favorable role in the NO reduction rate,probably owing to faster diffusion of the activated NO species on K-MnO_(x)than H-MnO_(x).This study will help to design promising metal oxide-zeolite hybrid catalysts by identifying the role of the acid sites in two different constituents.

Structural Engineering of Anode Materials for Low-Temperature Lithium-Ion Batteries:Mechanisms,Strategies,and Prospects

The severe degradation of electrochemical performance for lithium-ion batteries(LIBs)at low temperatures poses a significant challenge to their practical applications.Consequently,extensive efforts have been contributed to explore novel anode materials with high electronic conductivity and rapid Li^(+)diffusion kinetics for achieving favorable low-temperature performance of LIBs.Herein,we try to review the recent reports on the synthesis and characterizations of low-temperature anode materials.First,we summarize the underlying mechanisms responsible for the performance degradation of anode materials at subzero temperatures.Second,detailed discussions concerning the key pathways(boosting electronic conductivity,enhancing Li^(+)diffusion kinetics,and inhibiting lithium dendrite)for improving the low-temperature performance of anode materials are presented.Third,several commonly used low-temperature anode materials are briefly introduced.Fourth,recent progress in the engineering of these low-temperature anode materials is summarized in terms of structural design,morphology control,surface&interface modifications,and multiphase materials.Finally,the challenges that remain to be solved in the field of low-temperature anode materials are discussed.This review was organized to offer valuable insights and guidance for next-generation LIBs with excellent low-temperature electrochemical performance.

Low-temperature characteristicsof rubbers and performance testsof type 120 emergencyvalve diaphragms

Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.

Screening non-noble metal oxides to boost the low-temperature combustion of polyethylene waste in air

Globally,the efficient utilization of polymer wastes is one of the most important issues for current sustainable development topics.Herein,a green and efficient low-temperature combustion approach is proposed to deal with polymer wastes and recover heat energy,simultaneously alleviating the environment and energy crisis.Non-noble metal oxides(Al_(2)O_(3),Fe_(2)O_(3),NiO_(2),ZrO_(2),La_(2)O_(3)and CeO_(2)) were prepared,characterized and screened to boost the low-temperature combustion of polyethylene waste at 300℃ in air.The mass change,heat release and CO_(x) formation were studied in details and employed to evaluate the combustion rate and efficiency.It was found that CeO_(2)significantly enhanced the combustion rate and efficiency,which was respectively 2 and 7 times that of non-catalytic case.An interesting phenomenon was observed that the catalytic performance of CeO_(2) in polyethylene low-temperature combustion was significantly improved by the 7-day storage in the room environment or water treatment.XPS analysis confirmed the co-existence of Ce^(3+) and Ce^(4+) in CeO_(2),and the 7-day storage and water treatment promoted the amount of Ce^(3+),which facilitated the formation of the oxygen vacancies.That may be the reason why CeO_(2) exhibited excellent catalytic performance in polyethylene low-temperature combustion.

Advances in sodium-ion batteries at low-temperature: Challenges and strategies

With the continuing boost in the demand for energy storage,there is an increasing requirement for batteries to be capable of operation in extreme environmental conditions.Sodium-ion batteries(SIBs) have emerged as a highly promising energy storage solution due to their promising performance over a wide range of temperatures and the abundance of sodium resources in the earth's crust.Compared to lithiumion batteries(LIBs),although sodium ions possess a larger ionic radius,they are more easily desolvated than lithium ions.Fu rthermore,SIBs have a smaller Stokes radius than lithium ions,resulting in improved sodium-ion mobility in the electrolyte.Nevertheless,SIBs demonstrate a significant decrease in performance at low temperatures(LT),which constrains their operation in harsh weather conditions.Despite the increasing interest in SIBs,there is a notable scarcity of research focusing specifically on their mechanism under LT conditions.This review explores recent research that considers the thermal tolerance of SIBs from an inner chemistry process perspective,spanning a wide temperature spectrum(-70 to100℃),particularly at LT conditions.In addition,the enhancement of electrochemical performance in LT SIBs is based on improvements in reaction kinetics and cycling stability achieved through the utilization of effective electrode materials and electrolyte components.Furthermore,the safety concerns associated with SIBs are addressed and effective strategies are proposed for mitigating these issues.Finally,prospects conducted to extend the environmental frontiers of commercial SIBs are discussed mainly from three viewpoints including innovations in materials,development and research of relevant theoretical mechanisms,and intelligent safety management system establishment for larger-scale energy storage SIBs.

Temperature inversion enables superior stability for low-temperature Zn-ion batteries

It is challenging for aqueous Zn-ion batteries(ZIBs)to achieve comparable low-temperature(low-T)performance due to the easy-frozen electrolyte and severe Zn dendrites.Herein,an aqueous electrolyte with a low freezing point and high ionic conductivity is proposed.Combined with molecular dynamics simulation and multi-scale interface analysis(time of flight secondary ion mass spectrometry threedimensional mapping and in-situ electrochemical impedance spectroscopy method),the temperature independence of the V_(2)O_(5)cathode and Zn anode is observed to be opposite.Surprisingly,dominated by the solvent structure of the designed electrolyte at low temperatures,vanadium dissolution/shuttle is significantly inhibited,and the zinc dendrites caused by this electrochemical crosstalk are greatly relieved,thus showing an abnormal temperature inversion effect.Through the disclosure and improvement of the above phenomena,the designed Zn||V_(2)O_(5)full cell delivers superior low-T performance,maintaining almost 99%capacity retention after 9500 cycles(working more than 2500 h)at-20°C.This work proposes a kind of electrolyte suitable for low-T ZIBs and reveals the inverse temperature dependence of the Zn anode,which might offer a novel perspective for the investigation of low-T aqueous battery systems.

Molecular composition of low-temperature oxidation products of the heavy oil

Low-temperature oxidation(LTO)is the main reaction that affects fuel formation in the in-situ combustion process,which has important significance for the subsequent combustion propulsion and the successful extraction of crude oil.In this study,heavy oil was subjected to LTO reactions at different temperatures.Three types of reaction products with varying oxidation depths were characterized in terms of the number of oxygen atoms and the polarity of the molecule to reveal the low-temperature oxidation process of the heavy oil.Ketone compounds and acid polyoxides in the oil phase and deep oxidation products with a higher number of oxygen atoms in the coke were identified with increasing oxidation depth.The experimental results showed that the oxidation reaction of the heavy oil changed from kinetic-controlled to diffusion-controlled in the open oxidation system of the heavy oil as the oxidation depth increased.The oxidation reaction of the oil phase reached a maximum and stable value in oxygen content.The molecular compositions of the ketone compound and acid polyoxide did not change significantly with further increase in reaction temperature.The molecular compositions of the deep oxidation products with a higher number of oxygen atoms in the coke phase changed significantly.The coke precursor molecules with a lower oxygen content and condensation degree participated in the coke formation,and the oxidation reaction pathway and the complexity of the oxidation product component also increased.

Impact of Low-temperature Storage on Volatile Flavor Compounds in Prepared Pork Products

[Objectives]This study was conducted to explore the dynamic changes of volatile flavor compounds in prepared pork during storage at different low-temperature conditions.[Methods]Prepared pork was stored at 4,-4 and-18℃.The volatile flavor compounds of prepared pork were determined by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)at days 0,7,14,21 and 28,and relative odor activity value(OAV),principal component analysis(PCA)and cluster analysis(CA)were combined to analyze changes in volatile flavor compounds of prepared pork during storage.[Results]The total number of volatile flavor compounds gradually decreased with the prolongation of the storage period,and OAV analysis identified 22 key flavor compounds(OAV≥1).The results of PCA and CA showed that 2-methyl-1-butanol,1-octen-3-ol,linalool,cineole,hexanal and nonanal were the main key flavor components,and the degree of flavor degradation was low under both superchilling and freezing conditions.After 28 days of storage,the alcohol content in the chilling group was significantly higher than other two groups,and the overall content of volatile flavor compounds was also significantly higher than other two groups,indicating that the-4℃chilling storage was more favorable for maintaining the overall flavor of prepared pork.[Conclusions]This study provides a theoretical basis for finding a better storage method for prepared meat products.

Exceptional Performance of 3D Additive Manufactured NiFe Phosphite Oxyhydroxide Hollow Tubular Lattice Plastic Electrode for Large-Current-Density Water Oxidization

In this article,we report a 3D NiFe phosphite oxyhydroxide plastic electrode using high-resolution digital light processing(DLP)3D-printing technology via induced chemical deposition method.The as-prepared 3D plastic electrode exhibits no template requirement,freedom design,low-cost,robust,anticorrosion,lightweight,and micro-nano porous characteristics.It can be drawn to the conclusion that highly oriented open-porous 3D geometry structure will be beneficial for improving surface catalytic active area,wetting performance,and reaction–diffusion dynamics of plastic electrodes for oxygen evolution reaction(OER)catalysis process.Density functional theory(DFT)calculation interprets the origin of high activity of NiFe(PO_(3))O(OH)and demonstrates that the implantation of the–PO_(3)can effectively bind the 3d orbital of Ni in NiFe(PO_(3))O(OH),lead to the weak adsorption of intermediate,make electron more active to improve the conductivity,thereby lowing the transform free energy of*O to*OOH.The water oxidization performance of as-prepared 3D NiFe(PO_(3))O(OH)hollow tubular(HT)lattice plastic electrode has almost reached the state-of-the-art level compared with the as-reported large-current-density catalysts or 3D additive manufactured plastic/metal-based electrodes,especially for high current OER electrodes.This work breaks through the bottleneck that plagues the performance improvement of low-cost high-current electrodes.

Fluidized magnetization roasting of refractory siderite-containing iron ore via preoxidation-low-temperature reduction

Magnetization roasting is one of the most effective way of utilizing low-grade refractory iron ore.However,the reduction roasting of siderite(FeCO3)generates weakly magnetic wüstite,thus reducing iron recovery via weak magnetic separation.We systematically studied and proposed the fluidized preoxidation-low-temperature reduction magnetization roasting process for siderite.We found that the maghemite generated during the air oxidation roasting of siderite would be further reduced into wüstite at 500 and 550℃due to the unstable intermediate product magnetite(Fe_(3)O_(4)).Stable magnetite can be obtained through maghemite reduction only at low temperature.The optimal fluidized magnetization roasting parameters included preoxidation at 610℃for 2.5 min,followed by reduction at 450℃for 5 min.For roasted ore,weak magnetic separation yielded an iron ore concentrate grade of 62.0wt%and an iron recovery rate of 88.36%.Compared with that of conventional direct reduction magnetization roasting,the iron recovery rate of weak magnetic separation had greatly improved by 34.33%.The proposed fluidized preoxidation-low-temperature reduction magnetization roasting process can realize the efficient magnetization roasting utilization of low-grade refractory siderite-containing iron ore without wüstite generation and is unlimited by the proportion of siderite and hematite in iron ore.

Preparation of α-Bi_2O_3 from bismuth powders through low-temperature oxidation

α-Bi2O3 powders were prepared from nanometer Bi powders through low-temperature oxidation at less than 873.15 K. XRD, SEM, TEM and HRTEM were used to characterize the structure and morphology of Bi powders and Bi2O3 particles. Kinetic studies on the bismuth oxidation at low-temperatures were carried out by TGA method. The results show that bismuth beads should be reunited and oxidized to become irregular Bi2O3 powders. The bismuth oxidation follows shrinking core model, and its controlling mechanism varies at different reaction time. Within 0-10 min, the kinetics is controlled by chemical reaction, after that it is controlled by O2 diffusion in the solid α-Bi2O3 layer. The apparent activation energy is determined as 55.19 kJ/mol in liquid-phase oxidation.

Low-temperature catalytic oxidation of formaldehyde over Co_3O_4catalysts prepared using various precipitants

Co3O4 catalysts prepared with different precipitants（NH3·H2O,KOH,NH4HCO3,K2CO3 and KHCO3）were investigated for the oxidation of formaldehyde（HCHO）.Among these,KHCO3-precipitated Co3O4（KHCO3-Co） was the most active low-temperature catalyst,and was able to completely oxidize HCHO at the 100-ppm level to CO2 at 90℃.In situ diffuse reflectance infrared spectroscopy demonstrated that hydroxyl groups on the catalyst surface were regenerated by K~＋ and CO3^（2-）,thus promoting the oxidation of HCHO.Moreover,H2-temperature programmed reduction and X-ray photoelectron spectroscopy showed that employing KHCO3 as the precipitant increased the Co^3＋/Co^2＋molar ratio on the surface of the Co3O4 catalyst,thus further promoting oxidation.Structural characterization revealed that catalysts precipitated with carbonate or bicarbonate reagents exhibited greater specific surface areas and pore volumes.Overall,these data suggest that the high activity observed during the Co3O4 catalyzed oxidation of HCHO can be primarily attributed to the presence of K~＋ and CO3^（2-） on the Co3O4 surface and the favorable Co^3＋/Co^2＋ ratio.

Single atom gold catalysts for low-temperature CO oxidation

Low‐temperature CO oxidation is important for both fundamental studies and practical applica‐tions. Supported gold catalysts are generally regarded as the most active catalysts for low‐temperature CO oxidation. The active sites are traditionally believed to be Au nanoclusters or nanoparticles in the size range of 0.5–5 nm. Only in the last few years have single‐atom Au catalysts been proved to be active for CO oxidation. Recent advances in both experimental and theoretical studies on single‐atom Au catalysts unambiguously demonstrated that when dispersed on suitable oxide supports the Au single atoms can be extremely active for CO oxidation. In this mini‐review, recent advances in the development of Au single‐atom catalysts are discussed, with the aim of illus‐trating their unique catalytic features during CO oxidation.

Cyclic oxidation and hot corrosion of Al_2O_3 or Y_2O_3-dispersed low-temperature chromizing coating

Chromium coatings with and without Al_2O_3 or Y_2O_3 particles were prepared by chromizing the as-deposited Ni-film with and without Al_2O_3 or Y_2O_3 particles using a conventional pack-cementation method at 800 ℃. The cyclic oxidation at 800 ℃ and hot corrosion in molten 75% Na2SO4＋25% NaC1 at 800 ℃ of the three different chromizing coatings were investigated. The effects of Al_2O_3 or Y_2O_3 on the cyclic oxidation and hot corrosion behavior of the chromizing coatings were discussed. Microstructure results show that the codeposited Al_2O_3 or Y_2O_3 particles significantly retard the grain growth of the chromizing coating, which increases the cyclic oxidation and hot corrosion resistance of the chromizing coatings, due to the more rapid formation of purer and denser chromia scnle

Effect of different fillers on oxidation behavior of low-temperature chromizing coating

Three different chromizing coatings were produced on Ni substrate using a conventional pack-cementation method with Al2O3,Al2O3＋CeO2 and CeO2 acting as filler,respectively,at a greatly decreased temperature（700 ℃）.Effects of different fillers on the isothermal and cyclic oxidation resistance of chromizing coating in air at 850 ℃ were comparably investigated.Microstructure results show that the addition of CeO2 into the filler significantly retards the grain growth of the chromizing coating.Oxidation results indicate that the chromizing coating using CeO2 as filler exhibits somewhat increased oxidation resistance than the normal chromizmg coating,while the chromizing coating using Al2O3＋CeO2 as filler exhibits much better oxidation resistance.The effects of different fillers on the oxidation behaviors were discussed in detail.

Effects of Exogenous Glycine Betaine on Oxidation Metabolism in Cucumbers during Low-temperature Storage

[Objective] This study aimed to analyze the effects of different concentrations of glycine betaine（GB） on oxidation metabolism in cucumbers under low-temperature stress and to investigate the possible mechanism of low-temperature resistance in cucumber during low-temperature storage. [Method] Cucumber cultivar Zhongnong No.8 was treated with 0, 5, 10 and 15 mmol/L GB solutions for 15 min and stored at 4 ℃. Changes in oxidative metabolism-related parameters were observed. [Result] Increasing exogenous GB concentration could enhance GB content in cucumbers, decline lipoxygenase（LOX） activity, improve peroxidase（POD） and catalase（CAT） activities, remove effectively hydrogen peroxide（H2O2） and reduce the accumulation of malondialdehyde（MDA）. [Conclusion] Treating cucumbers with10 mmol/L GB exhibited the most remarkable effect.