Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios （Ce-Mn/GF） were prepared by an impregnation method and tested for low-temperature （80 180 ℃） selective cataly...Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios （Ce-Mn/GF） were prepared by an impregnation method and tested for low-temperature （80 180 ℃） selective catalytic reduction （SCR） of NO with ammonia. This brand-new technology could remove NO and particles matter from coal-fired flue gas. The surface properties of the catalysts were examined by means of Bmnauer-Emmett-Teller （BET）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and scanning electron microscopy （SEM）. The experimental results showed that the catalyst with a Ce/Mn molar ratio of 0.2 obtained high activity of 87.4% NO conversion at 150 ℃ under a high space velocity of 50000 h1. Deactivation poisoned by SO2 still occurred, but the Ce-Mn/GF（0.2） catalyst performed desirable tolerance to SO2 with decreasing 50% in 40 min and then maintaining at about 30% NO conversion. Characterization results indicated that the excellent low-temperature catalytic activity was related to the high specific surface area, pore structure, and amorphous phase.展开更多
Flame spray pyrolysis （FSP） was utilized to synthesize Ce-Mn oxides in one step for catalytic oxidation of benzene. Cerium acetate and manganese acetate were used as precursors. The materials synthesized were charac...Flame spray pyrolysis （FSP） was utilized to synthesize Ce-Mn oxides in one step for catalytic oxidation of benzene. Cerium acetate and manganese acetate were used as precursors. The materials synthesized were characterized using X-ray diffraction （XRD）, N2 adsorption, X-ray photoelectron spectroscopy （XPS）, transmission electron microscopy （TEM）, Raman spectroscopy, and H2-temperature programmed reduc- tion （H2-TPR） and their benzene catalytic oxidation behavior was evaluated. Mn ions were evidenced in multiple chemical states. Crystalline Ce-Mn oxides consist of particles with size 〈40 nm and specific sur- face areas （SSA） of 20-50 m2/g. Raman spectrums and H2-TPR results indicated the interaction between cerium and manganese oxides. Flame-made 12.5%-Ce-Mn oxide exhibited excellent catalytic activity at relatively low temperatures （T95 about 260℃） compared to other Ce-Mn oxides with different cerium- to-manganese ratios, Redox mechanism and strong interaction conform to structure analysis that Ce-Mn strong interaction formed during the high temperature flame process and the results were used to explain catalytic oxidation of benzene.展开更多
Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-bas...Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-based layered oxide cathodes-a leading candidate for PIB systems-has been fundamentally constrained by irreversible phase transitions(PT)during the cycling process,manifesting as severe structural degradation and capacity fading.This review presents a transformative paradigm integrating machine learning(ML)with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes.Through systematic ML-driven interrogation of structure-property relationships,we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics.Furthermore,we highlight recent breakthroughs in cross-disciplinary approaches,enabling the rational design of PT-mitigated cathode architectures.By consolidating these insights into a unified knowledge framework,this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems.展开更多
Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+d...Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.展开更多
With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysi...With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET.展开更多
In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic ac...In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic acid)ligand.Mg_(2)Ti-ABTC exhibited permanent porosity for N_(2),CO_(2),CH_(4),C_(2)H_(2),C_(2)H_(4),and C_(2)H_(6)gas adsorption.Further-more,Mg_(2)Ti-ABTC exhibited outstanding photocatalytic activity in the oxidation of aromatic sulfides to the corre-sponding sulfoxides under ambient air conditions.Mechanism studies reveal that photoinduced holes(h^(+)),the super-oxide radical(·O_(2)^(-)),and singlet oxygen(^(1)O_(2))are pivotal species involved in the photocatalytic oxidation reaction.展开更多
The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the ...The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.展开更多
Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising m...Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising methods for the removal of organic microcontaminants in the environment.Biogenic manganese oxides(BMO)are reported as catalysts due to their transitionmetal nature,and are also readily generated bymanganeseoxidizing microorganisms in the natural environment,and therefore their roles and effects in AOPs-based environmental remediation should be investigated.However,biogenic ironmanganese oxides(BFMO)are actually generated rather than BMO due to the coexistence of ferrous ionswhich can be oxidized to iron oxides.Therefore,this study produced BFMO originating from a highly efficientmanganese-oxidizing fungus Cladosporium sp.XM01 and chose peroxymonosulfate(PMS)as a typical oxidant for the degradation of bisphenol A(BPA),a model organic micropollutant.Characterization results indicate that the formed BFMO was amorphouswith a lowcrystallinity.The BFMO/PMS system achieved a high degradation performance that 85%BPA was rapidly degraded within 60min,and therefore the contribution of BFMO cannot be ignored during PMS-based environmental remediation.Different from the findings of previous studies(mostly radicals and singlet oxygen),the degradationmechanism was first proven as a 100%electron-transfer pathway mediated by high-valence Mn under acidic conditions provided by PMS.The findings of this study provide new insights into the degradation mechanisms of pollutants using biogenic metal oxides in PMS activation and the contribution of their coexistence in AOPs-based environmental remediation.展开更多
A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performa...A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performance and corresponding structural feature was comprehensively evaluated by XPS,in situ DRIFTS,BET,XRD,SEM and H_(2)-TPR.Meanwhile,10%Gd0.25Ce0.75/MPB exhibited excellent performance,favorable SO_(2) and moisture toleration over a broad temperature range from 160 to 320℃,where it achieved 96.8%removal efficiency with 90.5%selectivity at 200℃.The single or united effects of O_(2),SO_(2),H_(2)O on HCHO abatement over 10%Gd_(0.25)Ce_(0.75)/MPB were tested,and the findings demonstrated that the suppressive effects of SO_(2) and H_(2)O outweighed the promoting influence of O_(2) within a specific range.Gd and Ce co-modified MPB revealed superior HCHO removal capability in contrast to that of Gd or Ce severally modified MPB,ascribing to the synergistic effect of GdO_(x) and CeO_(x) and benefitting from the augmentation of surface area and total pore volume,the aggrandizement of surface active oxygen species,the promotion of redox ability and the inhibition crystallization of CeO_(x).According to in situ DRIFTS,a series of intermediates including formate species and dioxymethylene(DOM)were produced,which would eventually decompose into H_(2)O and CO_(2).In addition,the mass transfer and diffusion of the reactants along with the accessibility of the catalytic sites were enlarged by the hierarchical porous structure of the support,which were also answerable for its distinguished catalytic performance.Furthermore,10%Gd0.25Ce0.75/MPB possessed remarkable potential for industrial applications.展开更多
The Kitaev honeycomb model has received significant attention due to its exactly solvable quantum spin liquid ground states and fractionalized excitations.Layered cobalt oxides have been considered as a promising plat...The Kitaev honeycomb model has received significant attention due to its exactly solvable quantum spin liquid ground states and fractionalized excitations.Layered cobalt oxides have been considered as a promising platform for realizing this model.However,in contrast to the conventional wisdom regarding the single-q zigzag magnetic order inferred from previous studies of the candidate materials Na_(2)IrO_(3) and α-RuCl_(3),recent experiments on two representative honeycomb cobalt oxides,hexagonal Na_(2)Co_(2)TeO_(6) and monoclinic Na_(3)Co_(2)SbO_(6),have uncovered evidence for more complex multi-q zigzag order variants.This review surveys the experimental strategies used to distinguish between single-and multi-q orders,along with the crystallographic symmetries of cobalt oxides,in comparison with previously studied systems.The general formation mechanism of multi-q order is also briefly discussed.The goal is to provide a solid ground for examining the relevance of multi-q order in honeycomb cobalt oxides and discuss its implications for the microscopic model of these intriguing quantum magnets.展开更多
The use of metal oxides has been extensively documented in the literature and applied in a variety of contexts,including but not limited to energy storage,chemical sensors,and biomedical applications.One of the most s...The use of metal oxides has been extensively documented in the literature and applied in a variety of contexts,including but not limited to energy storage,chemical sensors,and biomedical applications.One of the most significant applications of metal oxides is heterogeneous catalysis,which represents a pivotal technology in industrial production on a global scale.Catalysts serve as the primary enabling agents for chemical reactions,and among the plethora of catalysts,metal oxides including magnesium oxide(MgO),ceria(CeO_(2))and titania(TiO_(2)),have been identified to be particularly effective in catalyzing a variety of reactions[1].Theoretical calculations based on density functional theory(DFT)and a multitude of other quantum chemistry methods have proven invaluable in elucidating the mechanisms of metal-oxide-catalyzed reactions,thereby facilitating the design of high-performance catalysts[2].展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
In this study,a string of Cr-Mnco-modified activated coke catalysts(XCryMn1-y/AC)were prepared to investigate toluene and Hg^(0) removal performance.Multifarious characterizations including XRD,TEM,SEM,in situ DRIFTS,...In this study,a string of Cr-Mnco-modified activated coke catalysts(XCryMn1-y/AC)were prepared to investigate toluene and Hg^(0) removal performance.Multifarious characterizations including XRD,TEM,SEM,in situ DRIFTS,BET,XPS and H_(2)-TPR showed that 4%Cr0.5Mn0.5/AC had excellent physicochemical properties and exhibited the best toluene and Hg^(0) removal efficiency at 200℃.By varying the experimental gas components and conditions,it was found that too large weight hourly space velocity would reduce the removal efficiency of toluene and Hg^(0).Although O_(2) promoted the abatement of toluene and Hg^(0),the inhibitory role of H_(2)O and SO_(2) offset the promoting effect of O_(2) to some extent.Toluene significantly inhibited Hg^(0) removal,resulting from that toluene was present at concentrations orders of magnitude greater than mercury’s or the catalyst was more prone to adsorb toluene,while Hg^(0) almost exerted non-existent influence on toluene elimination.The mechanistic analysis showed that the forms of toluene and Hg^(0) removal included both adsorption and oxidation,where the high-valent metal cations and oxygen vacancy clusters promoted the redox cycle of Cr^(3+)+Mn^(3+)/Mn^(4+)+Cr^(6+)+Mn^(2+),which facilitated the conversion and replenishment of reactive oxygen species in the oxidation process,and even the CrMn_(1.5)O_(4) spinel structure could provide a larger catalytic interface,thus enhancing the adsorption/oxidation of toluene and Hg^(0).Therefore,its excellent physicochemical properties make it a costeffective potential industrial catalyst with outstanding synergistic toluene and Hg^(0) removal performance and preeminent resistance to H_(2)O and SO_(2).展开更多
This study delved into the corrosion behavior of ZK60 Mg alloy in saturated NaCl solution,particularly focusing on the effects of the addition of rare earth oxide,namely CeO_(2)(forming ZKC alloy)and La_(2)O_(3)(formi...This study delved into the corrosion behavior of ZK60 Mg alloy in saturated NaCl solution,particularly focusing on the effects of the addition of rare earth oxide,namely CeO_(2)(forming ZKC alloy)and La_(2)O_(3)(forming ZKL alloy).The results indicate that the introduction of CeO_(2)and La_(2)O_(3)promotes the precipita-tion of T-(Mg_(1−x),Zn_(x))_(11)RE phases(Mg-Zn-RE phases,where RE represents Ce or La)at grain boundaries.The presence and distribution pattern of the T-phase have a profound impact on the corrosion resis-tance of the Mg alloy.Specifically,the ZKC alloy exhibits the most outstanding corrosion resistance.This superior performance is attributed to the uniform distribution of(Mg_(1−x),Zn_(x))_(11)Ce phase at grain bound-aries in ZK60-0.5 wt%CeO_(2),effectively hindering the penetration of corrosive media into the matrix.Additionally,scanning kelvin probe force microscopy(SKPFM)analysis reveals that the(Mg_(1−x),Zn_(x))_(11)Ce phase exhibits the smallest potential difference with the matrix,significantly mitigating the tendency for galvanic corrosion.In contrast,the ZKL alloy displays less precipitation and uneven distribution of the(Mg_(1−x),Zn_(x))_(11)La phase,resulting in inferior corrosion resistance compared to the ZKC alloy.The dispar-ities in the precipitation of the two phases,as derived from first-principles calculations,stem from the spontaneous reduction of CeO_(2)under Mg conditions,whereas the reduction reaction between La_(2)O_(3)and Mg cannot proceed spontaneously.Furthermore,SKPFM analysis and CALPHAD method found that as the addition of CeO_(2)/La_(2)O_(3)increases,the atomic ratio of Zn in the Mg-Zn-RE ternary phase rises,accompa-nied by an increase in the potential difference between the Mg-Zn-RE phase and the Mg matrix.This suggests that fine-tuning the addition of rare earth oxides can modify the atomic ratio of the Mg-Zn-RE ternary phase,thereby enhancing the corrosion resistance of the Mg alloy.In summary,this study not only unravels the specific mechanisms of how CeO_(2)and La_(2)O_(3)affect the corrosion behavior of ZK60 Mg alloy but also provides new strategies and insights for the development of low-cost,high-performance corrosion-resistant Mg alloy materials.展开更多
Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and re...Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery.Therefore,the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts.In this work,an efficient catalyst was developed with Co-N_(x)configuration facilely reconstructed on the surface of Co_(3)O_(4)(Co-N_(x)/Co_(3)O_(4)),which exhibited superior catalytic activity.We further fixed the highly efficient Co-N_(x)/Co_(3)O_(4)onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability.Results indicated that the inorganic ceramic membrane(CM)can achieve high water flux of 710 L m-2h-1,and the similar water flux can be achieved by Co-N_(x)/Co_(3)O_(4)/CM even without the pressure extraction.We also employed the Co-N_(x)/Co_(3)O_(4)/CM system to the wastewater secondary effluent,and the pollutant in complicated secondary effluent could be highly removed by the Co-N_(x)/Co_(3)O_(4)/CM system.This paper provides a new point of view for the application of metal-based catalysts with M-N_(x)coordination in catalytic reaction device.展开更多
A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields...A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields such as thermal barrier coatings,energy storage,dielectric materials,and transparent ceramics.However,there are limited reports on the dielectric properties of A_(2)B_(2)O_(7)high-entropy oxides.Consequently,further investigation is required to understand the polarization mechanisms in high-entropy ceramics and analyze the formation of oxygen vacancies and their influence.In the present study,La_(2)[(TiZrSnHfGe)_((1-2x)5)(NbGa)_(x)]_(2)O_(7)(x=0.129,0.143,0.157,0.171)(LTZSHGNGO)ceramics were synthesized successfully using a conventional solidstate reaction method.Compared withLa_(2)(TiZrSnHfGe)_(2)O_(7)ceramics,LTZSHGNGO demonstrated a nearly 6.7-fold increase in dielectric constant and a 33%reduction in dielectric loss.The incorporation of Nb/Ga enhanced the high-temperature dielectric properties and improved dielectric stability.The exceptional dielectric performance is primarily attributed to the synergistic highentropy effect,while Nb/Ga doping increased the number of oxygen vacancies and generated more defect dipole clusters[Ti^(4+)·e-V_(O)^(**)-Ti^(4+)·e].This study provides novel insights into the dielectric properties of LTZSHGNGO high-entropy ceramics and offers a novel approach to understanding the performance of A_(2)B_(2)O_(7)ceramics.展开更多
The vibrational resolved spectra of MO_(2)^(-)/MO_(2)(M=Ti,Zr,and Hf)are reported by using photoelectron imaging and theoretical calculations.The results indicate that all the ground states of anionic and neutral MO_(...The vibrational resolved spectra of MO_(2)^(-)/MO_(2)(M=Ti,Zr,and Hf)are reported by using photoelectron imaging and theoretical calculations.The results indicate that all the ground states of anionic and neutral MO_(2)(M=Ti,Zr,and Hf)compounds are formed in bent insertion structures.The observed ground-state adiabatic detachment energy(ADE)is measured to be 1.597±0.003,1.651±0.003,and 2.119±0.003 eV for TiO_(2)^(-),ZrO_(2)^(-),and HfO_(2)^(-),respectively.The vibrational frequencies of the anionic and neutral MO_(2)are also determined from the experimental spectra.The results of theoretical calculations show that the electronic configurations of MO_(2)^(-)are^(2)A_(1)with C_(2v)point group.Bond order analysis indicates that the two M-O bonds are all multiple characters.展开更多
Proton ceramic fuel cell efficiently converts chemical energy into electrical energy,representing a pivotal component of future energy systems.However,its current performance is hindered by limitations in cathode and ...Proton ceramic fuel cell efficiently converts chemical energy into electrical energy,representing a pivotal component of future energy systems.However,its current performance is hindered by limitations in cathode and electrolyte materials,thereby impeding commercialization.Anion doping emerges as a promising strategy to enhance the electrochemical efficiency of perovskite-based cathodes and electrolytes.However,integrating this approach within a single-cell structure still requires further research.In this study,F-doped perovskite oxides BaCo_(0.4)Fe_(0.4)Zr_(0.1)Y_(0.1)O_(2.9-δ)F_(0.1)(BCFZYF)and BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(2.9-δ)F_(0.1)(BZCYYbF)were synthesized for use as the cathode and electrolyte,respectively,in proton ceramic fuel cells.Our findings demonstrate that F-doped perovskite oxides exhibit superior electrochemical performance and enhanced structural stability.Furthermore,doping both electrodes and electrolytes with F ions improves their interfacial compatibility.The cell configuration BCFZYF|BZCYYbF|Ni-BZCYYbF achieved a peak power density of 998 mW·cm^(−2)at 650℃using H_(2)as fuel,and it maintained stable operation for over 400 h at 550℃with a current density of 400 mA·cm^(−2).This research underscores an effective strategy for enhancing the performance and durability of proton ceramic fuel cells.展开更多
Cryogenic magnetic cooling based on the principle of the magnetocaloric effects(MCEs)of magnetic solids has been recognized as an alternative cooling technology due to its significant economic and social benefits.Desi...Cryogenic magnetic cooling based on the principle of the magnetocaloric effects(MCEs)of magnetic solids has been recognized as an alternative cooling technology due to its significant economic and social benefits.Designing novel magnetic materials with good magnetocaloric performance is a prerequisite for practical applications.In this study,three gadolinium-transition metal-based high entropy oxides(HEOs)of Gd(Fe_(1/4)Ni_(1/4)Al_(1/4)Cr_(1/4))O_(3),Gd(Fe_(1/5)Ni_(1/5)Al_(1/5)Cr_(1/5)Co_(1/5))O_(3),and Gd(Fe_(1/6)Ni_(1/6)Al_(1/6)Cr_(1/6)Co_(1/6)Mn_(1/6))O_(3)were designed and systematically characterized regarding their structural and cryogenic magnetic properties.These HEOs were confirmed to crystallize into a single-phase perovskite-type orthorhombic structure with a homogeneous microstructure,reveal a second-order magnetic transition at low temperatures,and exhibit significant cryogenic MCEs.The magnetocaloric performances of the present HEOs,identified by magnetic entropy changes,relative cooling power,and temperature-averaged entropy changes,were com-parable with recently reported candidate materials.The present study indicates potential applications for cryogenic magnetic cooling of the present HEOs and provides meaningful clues for designing and exploring HEOs with good cryogenic magnetocaloric performances.展开更多
Rare earth metal elements include lanthanide elements as well as scandium and yttrium,totaling seventeen metal elements.Due to the wide application prospects of rare earth metal elements in various fields such as lumi...Rare earth metal elements include lanthanide elements as well as scandium and yttrium,totaling seventeen metal elements.Due to the wide application prospects of rare earth metal elements in various fields such as luminescent materials,magnetic materials,catalytic materials,electronic devices,they have an important strategic position.In the field of electrocatalysis,rare earth metal elements have great potential for development due to their unique 4f electron layer structure,spin orbit coupling,high reactivity,controllable coordination number,and rich optical properties.However,there is currently a lack of systematic reviews on the modification strategies of rare earth metal elements and the latest developments in electrocatalysis.Therefore,in order to stimulate the enthusiasm of researchers,this review focuses on the application progress of rare earth metal element modified metal oxides in multiple fields such as wastewater treatment,hydrogen peroxide synthesis,hydrogen evolution reaction(HER),carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and machine learning assisted research.In depth analysis of its electrocatalytic mechanism in various application scenarios and key factors affecting electrocatalytic performance.This review is of great significance for further developing high-performance and multifunctional electrocatalysts,and is expected to provide strong support for the development of energy,environment,and chemical industries.展开更多
基金Project supported by the National High Technology Research and Development Program of China(863 Program)(2008AA05Z305)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(201109)+2 种基金the Master Dissertation Innovation Funded Projects(EG2013015)the Fundamental Research Funds for the Central Universities Special Fund Project(11D11315)Program of Shanghai Subject Chief Scientist(14XD1424700)
文摘Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios （Ce-Mn/GF） were prepared by an impregnation method and tested for low-temperature （80 180 ℃） selective catalytic reduction （SCR） of NO with ammonia. This brand-new technology could remove NO and particles matter from coal-fired flue gas. The surface properties of the catalysts were examined by means of Bmnauer-Emmett-Teller （BET）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and scanning electron microscopy （SEM）. The experimental results showed that the catalyst with a Ce/Mn molar ratio of 0.2 obtained high activity of 87.4% NO conversion at 150 ℃ under a high space velocity of 50000 h1. Deactivation poisoned by SO2 still occurred, but the Ce-Mn/GF（0.2） catalyst performed desirable tolerance to SO2 with decreasing 50% in 40 min and then maintaining at about 30% NO conversion. Characterization results indicated that the excellent low-temperature catalytic activity was related to the high specific surface area, pore structure, and amorphous phase.
基金financial supports from National Nature Science Foundation of China(Grant No.51002154)Instrument Developing Project of the Chinese Academy of Sciences(Grant No.YZ200722)+2 种基金National High Technology Research and Development Program of China(Grant Nos.2012AA062702, 2010AA064903)the 12th Five-Year National Key Technology R&D Program(Grant Nos.2012BAJ02B03,2012BAJ02B07)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB05050300)
文摘Flame spray pyrolysis （FSP） was utilized to synthesize Ce-Mn oxides in one step for catalytic oxidation of benzene. Cerium acetate and manganese acetate were used as precursors. The materials synthesized were characterized using X-ray diffraction （XRD）, N2 adsorption, X-ray photoelectron spectroscopy （XPS）, transmission electron microscopy （TEM）, Raman spectroscopy, and H2-temperature programmed reduc- tion （H2-TPR） and their benzene catalytic oxidation behavior was evaluated. Mn ions were evidenced in multiple chemical states. Crystalline Ce-Mn oxides consist of particles with size 〈40 nm and specific sur- face areas （SSA） of 20-50 m2/g. Raman spectrums and H2-TPR results indicated the interaction between cerium and manganese oxides. Flame-made 12.5%-Ce-Mn oxide exhibited excellent catalytic activity at relatively low temperatures （T95 about 260℃） compared to other Ce-Mn oxides with different cerium- to-manganese ratios, Redox mechanism and strong interaction conform to structure analysis that Ce-Mn strong interaction formed during the high temperature flame process and the results were used to explain catalytic oxidation of benzene.
基金financially supported by the National Natural Science Foundation of China(U20A20247)the National Key Research and Development Program of the Ministry of Science and Technology(2022YFA1402504)+1 种基金Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(MATEC2023KF002)Guangdong Science and Technology Department(STKJ2021016)。
文摘Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-based layered oxide cathodes-a leading candidate for PIB systems-has been fundamentally constrained by irreversible phase transitions(PT)during the cycling process,manifesting as severe structural degradation and capacity fading.This review presents a transformative paradigm integrating machine learning(ML)with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes.Through systematic ML-driven interrogation of structure-property relationships,we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics.Furthermore,we highlight recent breakthroughs in cross-disciplinary approaches,enabling the rational design of PT-mitigated cathode architectures.By consolidating these insights into a unified knowledge framework,this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems.
基金supported by the National Natural Science Foundation of China(No.21805018)by Sichuan Science and Technology Program(Nos.2022ZHCG0018,2023NSFSC0117 and 2023ZHCG0060)Yibin Science and Technology Program(No.2022JB005)and China Postdoctoral Science Foundation(No.2022M722704).
文摘Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.
文摘With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET.
文摘In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic acid)ligand.Mg_(2)Ti-ABTC exhibited permanent porosity for N_(2),CO_(2),CH_(4),C_(2)H_(2),C_(2)H_(4),and C_(2)H_(6)gas adsorption.Further-more,Mg_(2)Ti-ABTC exhibited outstanding photocatalytic activity in the oxidation of aromatic sulfides to the corre-sponding sulfoxides under ambient air conditions.Mechanism studies reveal that photoinduced holes(h^(+)),the super-oxide radical(·O_(2)^(-)),and singlet oxygen(^(1)O_(2))are pivotal species involved in the photocatalytic oxidation reaction.
基金supported by the National Key R&D Program of China(No.2022YFB2404400)the National Natural Science Foundation of China(Nos.U23A20577,52372168,92263206 and 21975006)+1 种基金the“The Youth Beijing Scholars program”(No.PXM2021_014204_000023)the Beijing Natural Science Foundation(Nos.2222001 and KM202110005009).
文摘The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.
基金supported by the National Key Research and Development Program of China(No.2021YFC3200700)the National Natural Science Foundation of China(No.52400010)+1 种基金the Science and Technology Commission of Shanghai Municipality(No.24ZR1472300)the Fundamental Research Funds for the Central Universities.
文摘Bisphenol A(BPA)is a pervasive endocrine disruptor that enters the environment through anthropogenic activities,posing significant risks to ecosystems and human health.Advanced oxidation processes(AOPs)are promising methods for the removal of organic microcontaminants in the environment.Biogenic manganese oxides(BMO)are reported as catalysts due to their transitionmetal nature,and are also readily generated bymanganeseoxidizing microorganisms in the natural environment,and therefore their roles and effects in AOPs-based environmental remediation should be investigated.However,biogenic ironmanganese oxides(BFMO)are actually generated rather than BMO due to the coexistence of ferrous ionswhich can be oxidized to iron oxides.Therefore,this study produced BFMO originating from a highly efficientmanganese-oxidizing fungus Cladosporium sp.XM01 and chose peroxymonosulfate(PMS)as a typical oxidant for the degradation of bisphenol A(BPA),a model organic micropollutant.Characterization results indicate that the formed BFMO was amorphouswith a lowcrystallinity.The BFMO/PMS system achieved a high degradation performance that 85%BPA was rapidly degraded within 60min,and therefore the contribution of BFMO cannot be ignored during PMS-based environmental remediation.Different from the findings of previous studies(mostly radicals and singlet oxygen),the degradationmechanism was first proven as a 100%electron-transfer pathway mediated by high-valence Mn under acidic conditions provided by PMS.The findings of this study provide new insights into the degradation mechanisms of pollutants using biogenic metal oxides in PMS activation and the contribution of their coexistence in AOPs-based environmental remediation.
基金supported by the Scientific Research Project of Hunan Provincial EducationDepartment(No.22B0458)the National Natural Science Foundation of China(No.52270102).
文摘A chain of GdCe oxides boosted biochars derived from maize straw and sewage sludge(GdyCe1-y/MPBs)were fabricated for formaldehyde(HCHO)catalytic decomposition.The ingenerate relationship between the abatement performance and corresponding structural feature was comprehensively evaluated by XPS,in situ DRIFTS,BET,XRD,SEM and H_(2)-TPR.Meanwhile,10%Gd0.25Ce0.75/MPB exhibited excellent performance,favorable SO_(2) and moisture toleration over a broad temperature range from 160 to 320℃,where it achieved 96.8%removal efficiency with 90.5%selectivity at 200℃.The single or united effects of O_(2),SO_(2),H_(2)O on HCHO abatement over 10%Gd_(0.25)Ce_(0.75)/MPB were tested,and the findings demonstrated that the suppressive effects of SO_(2) and H_(2)O outweighed the promoting influence of O_(2) within a specific range.Gd and Ce co-modified MPB revealed superior HCHO removal capability in contrast to that of Gd or Ce severally modified MPB,ascribing to the synergistic effect of GdO_(x) and CeO_(x) and benefitting from the augmentation of surface area and total pore volume,the aggrandizement of surface active oxygen species,the promotion of redox ability and the inhibition crystallization of CeO_(x).According to in situ DRIFTS,a series of intermediates including formate species and dioxymethylene(DOM)were produced,which would eventually decompose into H_(2)O and CO_(2).In addition,the mass transfer and diffusion of the reactants along with the accessibility of the catalytic sites were enlarged by the hierarchical porous structure of the support,which were also answerable for its distinguished catalytic performance.Furthermore,10%Gd0.25Ce0.75/MPB possessed remarkable potential for industrial applications.
基金supported by the National Basic Research Program of China(Grant No.2021YFA1401901)the National Natural Science Foundation of China(Grant No.12474138)。
文摘The Kitaev honeycomb model has received significant attention due to its exactly solvable quantum spin liquid ground states and fractionalized excitations.Layered cobalt oxides have been considered as a promising platform for realizing this model.However,in contrast to the conventional wisdom regarding the single-q zigzag magnetic order inferred from previous studies of the candidate materials Na_(2)IrO_(3) and α-RuCl_(3),recent experiments on two representative honeycomb cobalt oxides,hexagonal Na_(2)Co_(2)TeO_(6) and monoclinic Na_(3)Co_(2)SbO_(6),have uncovered evidence for more complex multi-q zigzag order variants.This review surveys the experimental strategies used to distinguish between single-and multi-q orders,along with the crystallographic symmetries of cobalt oxides,in comparison with previously studied systems.The general formation mechanism of multi-q order is also briefly discussed.The goal is to provide a solid ground for examining the relevance of multi-q order in honeycomb cobalt oxides and discuss its implications for the microscopic model of these intriguing quantum magnets.
基金financial support from the National Key R&D Program of China(2021YFB3500700)the National Natural Science Foundation of China(22473042,22003016,and 92145302).
文摘The use of metal oxides has been extensively documented in the literature and applied in a variety of contexts,including but not limited to energy storage,chemical sensors,and biomedical applications.One of the most significant applications of metal oxides is heterogeneous catalysis,which represents a pivotal technology in industrial production on a global scale.Catalysts serve as the primary enabling agents for chemical reactions,and among the plethora of catalysts,metal oxides including magnesium oxide(MgO),ceria(CeO_(2))and titania(TiO_(2)),have been identified to be particularly effective in catalyzing a variety of reactions[1].Theoretical calculations based on density functional theory(DFT)and a multitude of other quantum chemistry methods have proven invaluable in elucidating the mechanisms of metal-oxide-catalyzed reactions,thereby facilitating the design of high-performance catalysts[2].
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金supported by the Scientific Research Project of Hunan Provincial Department of Education (No.22B0458)the National Natural Science Foundation of China (No.52270102).
文摘In this study,a string of Cr-Mnco-modified activated coke catalysts(XCryMn1-y/AC)were prepared to investigate toluene and Hg^(0) removal performance.Multifarious characterizations including XRD,TEM,SEM,in situ DRIFTS,BET,XPS and H_(2)-TPR showed that 4%Cr0.5Mn0.5/AC had excellent physicochemical properties and exhibited the best toluene and Hg^(0) removal efficiency at 200℃.By varying the experimental gas components and conditions,it was found that too large weight hourly space velocity would reduce the removal efficiency of toluene and Hg^(0).Although O_(2) promoted the abatement of toluene and Hg^(0),the inhibitory role of H_(2)O and SO_(2) offset the promoting effect of O_(2) to some extent.Toluene significantly inhibited Hg^(0) removal,resulting from that toluene was present at concentrations orders of magnitude greater than mercury’s or the catalyst was more prone to adsorb toluene,while Hg^(0) almost exerted non-existent influence on toluene elimination.The mechanistic analysis showed that the forms of toluene and Hg^(0) removal included both adsorption and oxidation,where the high-valent metal cations and oxygen vacancy clusters promoted the redox cycle of Cr^(3+)+Mn^(3+)/Mn^(4+)+Cr^(6+)+Mn^(2+),which facilitated the conversion and replenishment of reactive oxygen species in the oxidation process,and even the CrMn_(1.5)O_(4) spinel structure could provide a larger catalytic interface,thus enhancing the adsorption/oxidation of toluene and Hg^(0).Therefore,its excellent physicochemical properties make it a costeffective potential industrial catalyst with outstanding synergistic toluene and Hg^(0) removal performance and preeminent resistance to H_(2)O and SO_(2).
基金financial support from the National Natural Science Foundation of China(No.52201104)the Natural Science Foundation of Hunan Province(No.2023JJ40032)the Education Department of Hunan Province of China(No.24B0321).
文摘This study delved into the corrosion behavior of ZK60 Mg alloy in saturated NaCl solution,particularly focusing on the effects of the addition of rare earth oxide,namely CeO_(2)(forming ZKC alloy)and La_(2)O_(3)(forming ZKL alloy).The results indicate that the introduction of CeO_(2)and La_(2)O_(3)promotes the precipita-tion of T-(Mg_(1−x),Zn_(x))_(11)RE phases(Mg-Zn-RE phases,where RE represents Ce or La)at grain boundaries.The presence and distribution pattern of the T-phase have a profound impact on the corrosion resis-tance of the Mg alloy.Specifically,the ZKC alloy exhibits the most outstanding corrosion resistance.This superior performance is attributed to the uniform distribution of(Mg_(1−x),Zn_(x))_(11)Ce phase at grain bound-aries in ZK60-0.5 wt%CeO_(2),effectively hindering the penetration of corrosive media into the matrix.Additionally,scanning kelvin probe force microscopy(SKPFM)analysis reveals that the(Mg_(1−x),Zn_(x))_(11)Ce phase exhibits the smallest potential difference with the matrix,significantly mitigating the tendency for galvanic corrosion.In contrast,the ZKL alloy displays less precipitation and uneven distribution of the(Mg_(1−x),Zn_(x))_(11)La phase,resulting in inferior corrosion resistance compared to the ZKC alloy.The dispar-ities in the precipitation of the two phases,as derived from first-principles calculations,stem from the spontaneous reduction of CeO_(2)under Mg conditions,whereas the reduction reaction between La_(2)O_(3)and Mg cannot proceed spontaneously.Furthermore,SKPFM analysis and CALPHAD method found that as the addition of CeO_(2)/La_(2)O_(3)increases,the atomic ratio of Zn in the Mg-Zn-RE ternary phase rises,accompa-nied by an increase in the potential difference between the Mg-Zn-RE phase and the Mg matrix.This suggests that fine-tuning the addition of rare earth oxides can modify the atomic ratio of the Mg-Zn-RE ternary phase,thereby enhancing the corrosion resistance of the Mg alloy.In summary,this study not only unravels the specific mechanisms of how CeO_(2)and La_(2)O_(3)affect the corrosion behavior of ZK60 Mg alloy but also provides new strategies and insights for the development of low-cost,high-performance corrosion-resistant Mg alloy materials.
基金supported by National Natural Science Fundation of China(Nos.52170086,22308194,U22A20423)Natural Science Foundation of Shandong Province(No.ZR2021ME013)+1 种基金Taishan Scholars Program of Shandong Province(No.tsqn202211012)Shandong Provincial Excellent Youth(No.ZR2022YQ47)。
文摘Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery.Therefore,the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts.In this work,an efficient catalyst was developed with Co-N_(x)configuration facilely reconstructed on the surface of Co_(3)O_(4)(Co-N_(x)/Co_(3)O_(4)),which exhibited superior catalytic activity.We further fixed the highly efficient Co-N_(x)/Co_(3)O_(4)onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability.Results indicated that the inorganic ceramic membrane(CM)can achieve high water flux of 710 L m-2h-1,and the similar water flux can be achieved by Co-N_(x)/Co_(3)O_(4)/CM even without the pressure extraction.We also employed the Co-N_(x)/Co_(3)O_(4)/CM system to the wastewater secondary effluent,and the pollutant in complicated secondary effluent could be highly removed by the Co-N_(x)/Co_(3)O_(4)/CM system.This paper provides a new point of view for the application of metal-based catalysts with M-N_(x)coordination in catalytic reaction device.
基金financially supported by the National Natural Science Foundation of China(No.52201173)the S&T Program of Hebei(No.22567627H)+3 种基金the Natural Science Foundation of Hebei Province(No.E2021501017)Henan key Laboratory of Aeronautical Materials and Application Technology Open fund(No.ZHKF-230113)Hebei Key Laboratory of Dielectric and Electrolyte Functional Material,Northeastern University at Qinhuangdao(HKDEFM2021301)the Fundamental Research Funds for the Central Universities(No.2024GFYD002,N2323021)
文摘A_(2)B_(2)O_(7)high-entropy oxides are ceramic materials characterized by diverse compositions,strong structural inclusivity,and a broad range of potential applications.These materials hold significant value in fields such as thermal barrier coatings,energy storage,dielectric materials,and transparent ceramics.However,there are limited reports on the dielectric properties of A_(2)B_(2)O_(7)high-entropy oxides.Consequently,further investigation is required to understand the polarization mechanisms in high-entropy ceramics and analyze the formation of oxygen vacancies and their influence.In the present study,La_(2)[(TiZrSnHfGe)_((1-2x)5)(NbGa)_(x)]_(2)O_(7)(x=0.129,0.143,0.157,0.171)(LTZSHGNGO)ceramics were synthesized successfully using a conventional solidstate reaction method.Compared withLa_(2)(TiZrSnHfGe)_(2)O_(7)ceramics,LTZSHGNGO demonstrated a nearly 6.7-fold increase in dielectric constant and a 33%reduction in dielectric loss.The incorporation of Nb/Ga enhanced the high-temperature dielectric properties and improved dielectric stability.The exceptional dielectric performance is primarily attributed to the synergistic highentropy effect,while Nb/Ga doping increased the number of oxygen vacancies and generated more defect dipole clusters[Ti^(4+)·e-V_(O)^(**)-Ti^(4+)·e].This study provides novel insights into the dielectric properties of LTZSHGNGO high-entropy ceramics and offers a novel approach to understanding the performance of A_(2)B_(2)O_(7)ceramics.
基金supported by the National Natural Science Foundation of China(No.22273065)Shandong Energy institute(SEI U202312)"Strategic Priority Research Program"of the Chinese Academy of Sciences(No.XDA02020000).
文摘The vibrational resolved spectra of MO_(2)^(-)/MO_(2)(M=Ti,Zr,and Hf)are reported by using photoelectron imaging and theoretical calculations.The results indicate that all the ground states of anionic and neutral MO_(2)(M=Ti,Zr,and Hf)compounds are formed in bent insertion structures.The observed ground-state adiabatic detachment energy(ADE)is measured to be 1.597±0.003,1.651±0.003,and 2.119±0.003 eV for TiO_(2)^(-),ZrO_(2)^(-),and HfO_(2)^(-),respectively.The vibrational frequencies of the anionic and neutral MO_(2)are also determined from the experimental spectra.The results of theoretical calculations show that the electronic configurations of MO_(2)^(-)are^(2)A_(1)with C_(2v)point group.Bond order analysis indicates that the two M-O bonds are all multiple characters.
基金supported by the National Natural Science Foundation of China(No.22278203)The authors appreciate the support of Zhejiang Zheneng Technology and Environment Group Co.,Ltd’s project(No.TD-KJ-23-005:Methanation of carbon monoxide coupled with in-situ formed hydrogen in a low-temperature SOEC reactor).
文摘Proton ceramic fuel cell efficiently converts chemical energy into electrical energy,representing a pivotal component of future energy systems.However,its current performance is hindered by limitations in cathode and electrolyte materials,thereby impeding commercialization.Anion doping emerges as a promising strategy to enhance the electrochemical efficiency of perovskite-based cathodes and electrolytes.However,integrating this approach within a single-cell structure still requires further research.In this study,F-doped perovskite oxides BaCo_(0.4)Fe_(0.4)Zr_(0.1)Y_(0.1)O_(2.9-δ)F_(0.1)(BCFZYF)and BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(2.9-δ)F_(0.1)(BZCYYbF)were synthesized for use as the cathode and electrolyte,respectively,in proton ceramic fuel cells.Our findings demonstrate that F-doped perovskite oxides exhibit superior electrochemical performance and enhanced structural stability.Furthermore,doping both electrodes and electrolytes with F ions improves their interfacial compatibility.The cell configuration BCFZYF|BZCYYbF|Ni-BZCYYbF achieved a peak power density of 998 mW·cm^(−2)at 650℃using H_(2)as fuel,and it maintained stable operation for over 400 h at 550℃with a current density of 400 mA·cm^(−2).This research underscores an effective strategy for enhancing the performance and durability of proton ceramic fuel cells.
基金supported by the National Natural Science Foundation of China(No.52171174).The authors acknowledge Dr.Chao Zhang from the Instrumentation Service Center for Physical Sciences at Westlake University for magnetization measurements.
文摘Cryogenic magnetic cooling based on the principle of the magnetocaloric effects(MCEs)of magnetic solids has been recognized as an alternative cooling technology due to its significant economic and social benefits.Designing novel magnetic materials with good magnetocaloric performance is a prerequisite for practical applications.In this study,three gadolinium-transition metal-based high entropy oxides(HEOs)of Gd(Fe_(1/4)Ni_(1/4)Al_(1/4)Cr_(1/4))O_(3),Gd(Fe_(1/5)Ni_(1/5)Al_(1/5)Cr_(1/5)Co_(1/5))O_(3),and Gd(Fe_(1/6)Ni_(1/6)Al_(1/6)Cr_(1/6)Co_(1/6)Mn_(1/6))O_(3)were designed and systematically characterized regarding their structural and cryogenic magnetic properties.These HEOs were confirmed to crystallize into a single-phase perovskite-type orthorhombic structure with a homogeneous microstructure,reveal a second-order magnetic transition at low temperatures,and exhibit significant cryogenic MCEs.The magnetocaloric performances of the present HEOs,identified by magnetic entropy changes,relative cooling power,and temperature-averaged entropy changes,were com-parable with recently reported candidate materials.The present study indicates potential applications for cryogenic magnetic cooling of the present HEOs and provides meaningful clues for designing and exploring HEOs with good cryogenic magnetocaloric performances.
基金supported by the National Key Research and Development Program of China(No.2023YFC3708005)The Fundamental Research Funds for the Central Universities,Nankai University(No.63241208)supported by the National Natural Science Foundation of China(Nos.21872102 and 22172080)。
文摘Rare earth metal elements include lanthanide elements as well as scandium and yttrium,totaling seventeen metal elements.Due to the wide application prospects of rare earth metal elements in various fields such as luminescent materials,magnetic materials,catalytic materials,electronic devices,they have an important strategic position.In the field of electrocatalysis,rare earth metal elements have great potential for development due to their unique 4f electron layer structure,spin orbit coupling,high reactivity,controllable coordination number,and rich optical properties.However,there is currently a lack of systematic reviews on the modification strategies of rare earth metal elements and the latest developments in electrocatalysis.Therefore,in order to stimulate the enthusiasm of researchers,this review focuses on the application progress of rare earth metal element modified metal oxides in multiple fields such as wastewater treatment,hydrogen peroxide synthesis,hydrogen evolution reaction(HER),carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and machine learning assisted research.In depth analysis of its electrocatalytic mechanism in various application scenarios and key factors affecting electrocatalytic performance.This review is of great significance for further developing high-performance and multifunctional electrocatalysts,and is expected to provide strong support for the development of energy,environment,and chemical industries.
