Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability cau...Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.展开更多
In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied compara...In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts.展开更多
The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode compri...The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode comprising Ce-doped Ni-Fe-Se nanosheets grown on carbon cloth(Ni-Fe-Ce-Se/CC).This electrode was synthesized through a selenylation process,utilizing Ni-Fe-Ce-layered double hydroxide/carbon cloth(Ni-Fe-Ce LDH/CC)as the precursor.Notably,Ni-Fe-Ce-Se/CC electrode demonstrates remarkable performance,requiring a low overpotential of 300 mV to attain a current density of 100 mA·cm^(-2)under harsh alkaline conditions.Furthermore,the electrode exhibits exceptional stability during continuous operation for 100 h.Insight into the underlying mechanisms was gained through a combination of experimental results and density functional theory calculations.Our findings reveal that Ce doping induces crystal structure deformation in Ni-Fe-Se and enhances electron enrichment around Ni atoms.This structural modification optimizes the adsorption energy of oxygen-based intermediates on the Ni-Fe-Se surface.This work offers a valuable strategy for regulating the electron transfer and adsorption capabilities of transition metal selenide electrocatalysts through RE atoms doping,opening new avenues for enhanced electrocatalytic performance.展开更多
Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl oxidation.In the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showin...Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl oxidation.In the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showing a high activity in the catalytic oxidation of HCl to Cl_(2).The results on some extensive characterizations of both Ce-doped TiO_(2)carriers and their supported RuO_(2)catalysts show that the doping of Ce into TiO_(2)can effectively change the lattice parameters of TiO_(2)to improve the dispersion of the active RuO_(2)species on the carrier,which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions.This work provides some scientific basis and technical support for chlorine recycling.展开更多
The physicochemical properties of Pd and Pd-Pt catalysts which possess different Ce doping position were investigated by techniques of TEM, XRD, N2 adsorption-desorption, XPS and FT-IR. The catalytic performance for m...The physicochemical properties of Pd and Pd-Pt catalysts which possess different Ce doping position were investigated by techniques of TEM, XRD, N2 adsorption-desorption, XPS and FT-IR. The catalytic performance for methanol total oxidation was examined to study the effects of Ce adding position.CeO2-Al2 O3-TiO2（CAT） catalysts that Ce is directly introduced into support show higher reactivity and CO2 selectivity than CeO2/Al2 O3-TiO2（Ce/AT） samples in which Ce is loaded by impregnation method.The characterization results reveal that the Ce doping position does not cause obvious otherness of basic crystalline phase and mesoporous structure of support. However, the Ce doping position affects the pore shapes of support and then influences the pore diameter. CAT catalysts possess more abundant adsorbed oxygen and more Ti3＋ can transform the more gaseous oxygen into the active oxygen species on the catalyst surface, which is beneficial to the reaction. The Al-O-Ti bridges in CAT facilitate the cooperation of Al and Ti species, which further speeds up the reaction rate.展开更多
Electrochemical nitrogen reduction reaction(NRR)is a promising method for the synthesis of ammonia(NH3).However,the electrochemical NRR process remains a great challenge in achieving a high NH3 yield rate and a high F...Electrochemical nitrogen reduction reaction(NRR)is a promising method for the synthesis of ammonia(NH3).However,the electrochemical NRR process remains a great challenge in achieving a high NH3 yield rate and a high Faradaic efficiency(FE)due to the extremely strong N≡N bonds and the competing hydrogen evolution reaction(HER).Recently,bismuth telluride(Bi_(2)Te_(3))with two-dimensional layered structure has been reported as a promising catalyst for N_(2)fixation.Herein,to further enhance its NRR activity,a general doping strategy is developed to introduce and modulate the crystal defects of Bi_(2)Te_(3)nanosheets by adjusting the amount of Ce dopant(denoted as Ce_(x)-Bi_(2)Te_(3),where x represents the designed molar ratio of Ce/Bi).Meanwhile,the crystal defects can be designed and controlled by means of ion substitution and charge compensation.At−0.60 V versus the reversible hydrogen electrode(RHE),Ce_(0.3)-Bi_(2)Te_(3)exhibits a high NH_(3) yield(78.2μg·h^(−1)·mgcat^(−1)),a high FE(19.3%),excellent structural and electrochemical stability.Its outstanding catalytic activity is attributed to the tunable crystal defects by Ce doping.This work not only contributes to enhancing the NRR activity of Bi_(2)Te_(3)nanosheets,but also provides a reliable approach to prepare high-performance electrocatalysts by controlling the type and concentration of crystal defects for artificial N_(2)fixation.展开更多
The V-based body-centered cubic(BCC)-type hydrogen storage alloys have attracted significant attention due to their high theoretical hydrogen storage capacity of3.80 wt%.However,their practical application faces chall...The V-based body-centered cubic(BCC)-type hydrogen storage alloys have attracted significant attention due to their high theoretical hydrogen storage capacity of3.80 wt%.However,their practical application faces challenges related to low dehydriding capacity and poor activation performance.To overcome these challenges,a BCC-type Ti-V-Cr-Mn-Mo-Ce high-entropy alloy(HEA)with an effectively dehydriding capacity of 2.5 wt% above 0.1 MPa was prepared.By introduction of Mo and conducting heat treatment,the precipitation of Ti-rich phase in HEA was successfully suppressed,resulting in improved compositional uniformity and dehydriding capacity.Consequently,the effective dehydriding capacity increased significantly from 0.60 wt% to 2.50 wt% at 65℃,surpassing that of other types of hydrogen storage alloys under the same conditions.Moreover,the addition of 1 wt%Ce enabled initial hydrogen absorption at 25℃ without the need for activation at 400℃.Furthermore,Ce doping reduced the dehydriding activation energy of the Ti-V-Cr-Mn-Mo-Ce HEA from 52.71 to 42.82 kJ·mol^(-1)Additionally,the enthalpy value of dehydrogenation decreased from 46.89 to 17.96 k J·mol^(-1),attributed to a decrease in the hysteresis factor from 0.68 to 0.52.These findings provide valuable insights for optimizing the hydrogen storage property of HEA.展开更多
Isothermal oxidation resistance,oxide scale evolution and failure mechanism of Ce-doped Co-Al-W-MoTa-B alloy(0.01 at%,0.05 at%,0.10 at%and 0.20 at%Ce)exposed at 800℃were compared.The 0.01 Ce and 0.05 Ce alloys were c...Isothermal oxidation resistance,oxide scale evolution and failure mechanism of Ce-doped Co-Al-W-MoTa-B alloy(0.01 at%,0.05 at%,0.10 at%and 0.20 at%Ce)exposed at 800℃were compared.The 0.01 Ce and 0.05 Ce alloys were consisted ofγ/γ’coherent micro structure,while theκ-Co_(3)W compound precipitated at the grain boundary of the 0.1 OCe and 0.20 Ce alloys in addition to theγ/γ’microstructure.The oxidation kinetics curves of the Cedoped alloys exhibited a parabolic time dependence on the weight gain.With an increasing nominal Ce content,the weight gain of the Co-Al-W-Mo-Ta-B alloys monotonically decreased.An oxide scale composed of a dense and uniform outer Co_(3)O_(4)+CoO layer,a middle CoAl2 O4 and CoWO4 compound layer and an inner Al_(2)O_(3)layer.The excellent oxidation resistance of 0.2 Ce alloy was mainly attributed to a shorter incubation stage for the formation of the continuous and protective Al_(2)O_(3)layer and the thickest Al_(2)O_(3)layer during entire oxidation process.展开更多
Ce and C-S codoped mesoporous TiO_(2)nanocomposites were synthesized via a sol-gel method integrated with an evaporation-induced self-assembly approach.The basic physicochemical characteristics of the synthetic sample...Ce and C-S codoped mesoporous TiO_(2)nanocomposites were synthesized via a sol-gel method integrated with an evaporation-induced self-assembly approach.The basic physicochemical characteristics of the synthetic samples were analyzed via a series of characterization techniques.The results reveal that C-S and Ce codoping on mesoporous TiO_(2)enhances the photocatalytic activity owing to the synergistic effect caused by narrowing the band gap,enhancing adsorption,trapping and transferring the excited e^(-)/h^(+)pairs and suppressing the recombination of e^(-)/h^(+)pairs.Furthermore,the obtained C,S-TiO_(2)/CeO_(2)materials exhibit large specific surface areas and numerous pores which not only effectively improve the adsorption-enrichment capability,but also supply multi-dimensional mass and electron transfer channels.The photodegradation efficiency of RhB by C,S-TiO_(2)/CeO_(2)within 40 min is nearly 100%,and its degradation efficiency is 6.63 times that of undoped TiO_(2).Recycling experiments show that mesoporous C,S-TiO_(2)/CeO_(2)shows excellent recoverability and stability.Furthermore,by trapping experiments,·O_(2)e^(-)/h^(+)and·OH are the predominant active species and a possible reaction mechanism is proposed.展开更多
Hierarchical ZSM-5(HZ)molecular sieves based on fly ash were synthesized using a method combining water heat treatment with step-by-step calcination.The coupling catalysts between La_(1-x)Ce_(x)Mn_(0.8)-Ni_(0.2)O_(3)(...Hierarchical ZSM-5(HZ)molecular sieves based on fly ash were synthesized using a method combining water heat treatment with step-by-step calcination.The coupling catalysts between La_(1-x)Ce_(x)Mn_(0.8)-Ni_(0.2)O_(3)(x≤0.5)perovskites and HZ were prepared through the impregnation method,which were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),N_(2)adsorption,X-ray photoelectron spectroscopy(XPS),NH3-temperature programmed desoprtion(NH3-TPD),H_(2)-temperature programmed reduction(H_(2)-TPR)and O_(2)-TPD techniques and investigated regarding pentanal oxidation at 120-390℃to explore the effects of Ce doping on the catalytic activity and the active oxygen species of the coupling catalysts,meanwhile,the reaction mechanism and pathway of pentanal oxidation were also studied.The results reveal that Ce substitution at La sites can change the electronic interactions between all the elements and promote the electronic transfer among La,Ce,Ni,Mn and HZ,influencing directly the physicochemical characteristics of the catalysts.Moreover,the amount and transfer ability of surface adsorbed oxygen(O_(2)-and O-)regarded as the reactive oxygen species and the low temperature reducibility are the main influence factors in pentanal oxidation.Additionally,La_(0.8)Ce_(0.2)Mn_(0.8)Ni_(0.2)O_(3)/HZ exhibits the best catalytic activity and deep oxidation capacity as well as a better water resistance due to its larger amount of surface adsorbed oxygen species and higher low temperature reducibility.What’s more,appropriate Ce substitution can significantly enhance the amount of O_(2)-ions,which can distinctly enhance the catalytic activity of the catalyst,and moderate acid strength and appropriate acid amount can also facilitate the improvement of the pentanal oxidation activity.It is found that there is a synergic catalytic effect between surface acidity and redox ability of the catalyst.According to the in situ DRIFTS and GC/MS analyses,pentanal can be oxidized gradually to CO_(2)and H_(2)O by the surface oxygen species with the form of adsorption in air following the Langmuir-Hinshelwood(L-H)reaction mechanism.Two reaction pathways for the pentanal oxidation process are proposed,and the conversion of the formates to carbonates may be one of the main rate-determining steps.展开更多
Fe-based catalysts have a great potential to be used for selective catalytic reduction(SCR)of NO_(x)with NH3 reaction due to their low cost,nontoxicity and excellent catalytic activity.The aim of this paper is to inve...Fe-based catalysts have a great potential to be used for selective catalytic reduction(SCR)of NO_(x)with NH3 reaction due to their low cost,nontoxicity and excellent catalytic activity.The aim of this paper is to investigate Ce doping effect on activity of NH_(3)-SCR over the FeO_(x)/TiO_(2)catalyst.In-situ diffuse reflectance infrared fourier transform(DRIFT)technology was utilized to verity the adsorbed species on the surface of FeO_(x)/TiO_(2)and FeO_(x)-CeO_(2)/TiO_(2)catalysts.With respect to the obtained results,among the four catalysts studied,the FeO_(x)-CeO_(2)/TiO_(2)with the FeO_(x)/CeO_(2)ratio of 3/8 shows the best NO conversion more than 98%in the temperature range of 230—350℃,The active centers for NH_(3)adsorption and activation are assigned to Lewis acid sites over the FeO_(x)-CeO_(2)/TiO_(2)and monodentate nitrates can act as the key intermediate in the NH3-SCR.Moreover,both of Langmuir-Hinshelwood and Eley-Rideal mechanisms are observed over the FeO_(x)-CeO_(2)/TiO_(2)catalysts in the SCR.展开更多
The Ce-TiO2/KL （diatomite） ball photocatalyst was prepared and characterized based on the pretreated diatomite. The resuits showed that comparing with the crude diatomite, proper pretreatment could significantly imp...The Ce-TiO2/KL （diatomite） ball photocatalyst was prepared and characterized based on the pretreated diatomite. The resuits showed that comparing with the crude diatomite, proper pretreatment could significantly improve its SiO2 purity and specific surface area. The surface of diatomite was clear with uniform pore structure and big pore size. With diatomite ball as carder, the supported Ce-TiO2/KL ball photocatalyst was prepared by sol-gel method. The photocatalytic performances of the supported Ce-TiO2/ KL ball and Ce-TiO2/KL powder photocatalysts under various preparation conditions were studied in view of photocatalytic degrada- tion rate of Rhodamine B （Rh B） solution. The degradation rate of the ball photocatalysts for Rh B reached 94.6% and could be reused for many times, which showed much better photocatalytic performance and stability than powder photocatalysts.展开更多
SnSe exhibits excellent thermoelectric performance in both n-and p-type single crystals,but its n-type polycrystals are restricted because of the lower electrical conductivity.Here,we dually introduced rare earth elem...SnSe exhibits excellent thermoelectric performance in both n-and p-type single crystals,but its n-type polycrystals are restricted because of the lower electrical conductivity.Here,we dually introduced rare earth element Ce and PbTe to optimize the thermoelectric properties of n-type SnSe polycrystals.It is demonstrated that Ce is an effective cationic dopant to convert SnSe from p-to n-type conductor,and an enhanced peak zT value of∼0.9 at 823 K was obtained in Sn 0.97 Ce 0.03 Se due to the improved power factor.Furthermore,PbTe alloying not only reduced the band gap to increase the carrier concentration,but also enhanced the density-of-states effective mass,and hence further increased the power factor in the whole measured temperature range.Meanwhile,the lattice thermal conductivity was significantly reduced owing to the enhanced phonon scattering by the mass and strain fluctuations.As a result,the peak zT value was increased to∼1.3 for Sn 0.9 Pb 0.07 Ce 0.03 Se 0.93 Te 0.07 together with a high average zT value of∼0.52 in the temperature range of 300 to 823 K.展开更多
The intrinsic activity of Co(OH)_(2) for oxygen evolution reaction(OER)may be elaborately improved through the suitable valence adjustment.Ce modification at electronic level is proved to be an efficient strategy owin...The intrinsic activity of Co(OH)_(2) for oxygen evolution reaction(OER)may be elaborately improved through the suitable valence adjustment.Ce modification at electronic level is proved to be an efficient strategy owing to the flexible transformation of Ce^(3+)/Ce4+.Herein,Ce0.21@Co(OH)_(2) with the optimized Ce doping have been fabricated to tailor the fast electron transfer for the enhanced activity and stability for OER.Firstly,the obtained core-shell structure composed of vertical loose Co(OH)_(2) sheets not only exposes a large number of active sites,but also provides channels for Ce doping.Secondly,the high pressure microwave with instantaneous heating can fast introduce Ce into Co(OH)_(2),obtaining Cex@Co(OH)_(2) with well dispersion and close integration.The intimated interaction between Ce and Co species may provide the"d-f electronic ladders"for accelerating electron transfer of the catalytic surface.Meanwhile,Ce promotes the formation of Co-superoxide intermediate and/or the release of oxygen,which is considered to be the rate-determining step for OER.The electrochemical measurements confirmed the low overpotential of 300 m V at 10 m A cm^(-2) and great stability of Ce0.21@Co(OH)_(2) for OER.This work demonstrates a meaningful approach to realize the tuned electronic structure through metal doping.展开更多
In order to improve the ability of SCR catalyst to catalyze the oxidation of gaseous elemental mercury,a series of novel Ce modified SCR(Selection Catalytic Reduction,V_(2)O_(5)-WO_(3)/TiO_(2))catalysts were prepared ...In order to improve the ability of SCR catalyst to catalyze the oxidation of gaseous elemental mercury,a series of novel Ce modified SCR(Selection Catalytic Reduction,V_(2)O_(5)-WO_(3)/TiO_(2))catalysts were prepared via two-step ultrasonic impregnation method.The performance of Ce/SCR catalysts on Hg^(0)oxidation and NO reduction as well as the catalytic mechanism on Hg^(0)oxidation was also studied.The XRD,BET measurements and XPS were used to characterize the catalysts.The results showed that the pore volume and pore size of catalyst was reduced by Ce doping,and the specific surface area decreased with the increase of Ce content in catalyst.The performance on Hg^(0)oxidation was promoted by the introduction of CeO_(2).Ce_(1)/SCR(1%Ce,wt.%)catalyst exhibited the best Hg^(0)oxidation activity of 21.2%higher than that of SCR catalyst at 350℃,of which the NO conversion efficiency was also higher at 200-400℃.Furthermore,Ce_(1)/SCR showed a better H_(2)O resistance but a slightly weaker SO_(2)resistance than SCR catalyst.The chemisorbed oxygen and weak absorbed oxygen on the surface of catalyst were increased by the addition of CeO_(2).The chemisorbed oxygen and weak absorbed oxygen on the surface of catalyst were increased by the addition of CeO_(2).The Ce_(1)/SCR possed better redox ability compared with SCR catalyst.HCl was the most effective gas responsible for the Hg^(0)oxidation,and the redox cycle(V^(4+)+Ce^(4+)←→V^(5+)+Ce^(3+))played an important role in promoting Hg^(0)oxidation.展开更多
A series of KY3F10 nanophosphors doped with Gd3＋, Ce3＋ and Eu3＋ ions were obtained with the use of a co-precipitation method. The resulting products were white precipitates, consisting of spherical particles with d...A series of KY3F10 nanophosphors doped with Gd3＋, Ce3＋ and Eu3＋ ions were obtained with the use of a co-precipitation method. The resulting products were white precipitates, consisting of spherical particles with diameter about 150-200 nm, which was confirmed using transmission electron microscopy （TEM） technique. Powder X-ray diffraction （XRD） and energy dispersive X-ray analysis （EDX） measurements confirmed appropriate structures of the nanoparticles obtained. Spectroscopic properties of the prod- ucts were examined on the basis of the measured excitation/emission spectra and luminescence decay curves. The synthesized sam- ples showed orange-red luminescence, characteristic for Eu3＋ ions. The reaction process was performed in required alkaline pH ad- justed with the use of ethylenediaminetetraacetic acid （EDTA） and potassium hydroxide. The samples containing large amounts of Gd3＋ dooant ions exhibited a tendencv to form nroducts with different momhologies.展开更多
Ce3＋-doped yttrium lanthanum oxide （Y0.9La0.1）2O3 transparent ceramics is fabricated with nanopowders and sintered in H2 atmosphere. The spectral properties of Ce：（Y0.9La0.1）2O3 transparent ceramics are investig...Ce3＋-doped yttrium lanthanum oxide （Y0.9La0.1）2O3 transparent ceramics is fabricated with nanopowders and sintered in H2 atmosphere. The spectral properties of Ce：（Y0.9La0.1）2O3 transparent ceramics are investigated. There appear two characteristic absorption peaks of Ce3＋ ions at 230~nm and 400~nm, separately. It is found that Ce3＋ ions can efficiently produce emission at 384~nm from （Y0.9La0.1）2O3 transparent ceramic host, while the emission is completely quenched in Re2O3 （Re=Y, Lu, La） host materials.展开更多
Thispaperisconcerned withthe preparation ofcerium doped yttrium iron garnet which areknown to be an oxide withlarge magneto opticaleffect. Usingtheimproved flux method wesuccessfully grew the bulksinglecrystalsofiron...Thispaperisconcerned withthe preparation ofcerium doped yttrium iron garnet which areknown to be an oxide withlarge magneto opticaleffect. Usingtheimproved flux method wesuccessfully grew the bulksinglecrystalsofiron garnet doped by Ce 3 + ions with maximum substitution upto0 349. Here weinvestigatedthedifferentcomposition ofsolution for maxi mum Ce3 + substitution. Thespectra ofthe Faraday rotation andtheoptical absorption were measured inthenearinfrared region fordifferentCe3 + ionsdopediron garnets. The Cesub stitution prominentlyenhancesthe Faradayeffect,andthe Yb and Euionssubstitutefor Yinthe dodecahedralsitesof YIGcanincreasetheconcentration of Ce3 + ions, depresstheforma tion of nonmagnetic Ce4 + ionsbythechargecompensation.展开更多
Solid-state sodium batteries (SSSBs) are gaining significant attention for their potential in electrochemical energy storage. However, the development of SSSBs is hindered by the low ionic conductivity of sodium-ion s...Solid-state sodium batteries (SSSBs) are gaining significant attention for their potential in electrochemical energy storage. However, the development of SSSBs is hindered by the low ionic conductivity of sodium-ion solid electrolytes (SSEs). Herein, Ce with a relatively large ionic radius is employed to replace Zr in Na_(3)Zr_(2)Si_(2)PO_(12) (NZSP), aiming to increase the ionic conductivity of the SSEs. Through structural analysis and theoretical calculations, it is inferred that Ce doping is favorable for stabilizing phases with higher ionic conductivity, increasing the Na^(+) concentration via the substitution of Zr^(4+) with Ce^(3+), and facilitating the generation of a densified microscopic morphology. The Ce-doped NZSP achieves a high room-temperature conductivity of 2.08 mS·cm^(−1) and good interfacial compatibility with Na metal. Furthermore, the assembled Na_(3)V2(PO4)3 cell based on Ce-doped NZSP maintains a capacity of 111.18 mAh·g^(−1) at 0.5 C after 200 cycles, with a high retention of 98.06%.展开更多
The electrooxidation of 5-hydroxymethylfurfural(HMFOR)not only offers a green route to attain high-value 2,5-furandicarboxylic acid(FDCA)from biomass,but also is considered as a promising approach to replace the kinet...The electrooxidation of 5-hydroxymethylfurfural(HMFOR)not only offers a green route to attain high-value 2,5-furandicarboxylic acid(FDCA)from biomass,but also is considered as a promising approach to replace the kinetically sluggish OER for future hydrogen production.Herein,we report the construction and structural optimization of Ce-doped ultrasmall Co_(2)P nanoparticles(NPs)in carbon-based nanoarrays to boost HER-coupled HMFOR.We demonstrate that the electronic structure of Co-based electrocatalysts can be positively regulated by Ce doping and the optimized Ce-Co_(2)P-based electrocatalyst only require a low voltage of 1.20 V vs.RHE to achieve 10 m A cm^(-2)for HMFOR with an excellent FDCA Faraday efficiency(FEFDCA)of 98.5%,which are superior to its Ce-free counterpart(1.29 V vs.RHE;FEFDCA=83.9%).When being assembled into a HERcoupled HMFOR system,this bifunctional electrocatalyst can achieve 50 m A cm^(-2)with an ultralow voltage of 1.46 V,which is reduced by 210 m Vas compared with that of its Ce-free counterpart(1.67 V).Quasi-operando experiments and DFTcalculations further reveal the significant roles of Ce doping in promoting the charge transfer between active sites and HMF,and reducing the free energy barrier of intermediate(^(*)HMFCA)dehydrogenation.This study provides new insights into the underlying mechanisms of Ce doping into metal phosphides for boosting HER-coupled HMFOR,developing a facile methodology to construct efficient electrocatalysts for energy storage/conversion systems.展开更多
基金support from the Free Exploration Project of Frontier Technology for Laoshan Laboratory(No.16-02)the National Natural Science Foundation of China(Nos.22072015 and 21927811)。
文摘Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.
基金Project supported by the Guangxi Natural Science Foundation(2014GXNSFAA118057)Guangxi Science and Technology Planning Project(AB16380276)
文摘In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts.
基金supported by the National Key Technology R&D Program of China(Nos.2021YFB3500801,2022YFB3504302 and 2022YFC3901503)the Natural Science Foundation and Overseas Talent Projects of Jiangxi Province(Nos.0232BAB214025 and 20232BCJ25044)the Double Thousand Plan of Jiangxi Province(No.jxsq2023201002).
文摘The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode comprising Ce-doped Ni-Fe-Se nanosheets grown on carbon cloth(Ni-Fe-Ce-Se/CC).This electrode was synthesized through a selenylation process,utilizing Ni-Fe-Ce-layered double hydroxide/carbon cloth(Ni-Fe-Ce LDH/CC)as the precursor.Notably,Ni-Fe-Ce-Se/CC electrode demonstrates remarkable performance,requiring a low overpotential of 300 mV to attain a current density of 100 mA·cm^(-2)under harsh alkaline conditions.Furthermore,the electrode exhibits exceptional stability during continuous operation for 100 h.Insight into the underlying mechanisms was gained through a combination of experimental results and density functional theory calculations.Our findings reveal that Ce doping induces crystal structure deformation in Ni-Fe-Se and enhances electron enrichment around Ni atoms.This structural modification optimizes the adsorption energy of oxygen-based intermediates on the Ni-Fe-Se surface.This work offers a valuable strategy for regulating the electron transfer and adsorption capabilities of transition metal selenide electrocatalysts through RE atoms doping,opening new avenues for enhanced electrocatalytic performance.
基金supported by Zhejiang Provincial Key R&D Project(No.2021C01056)the Programme of Introducing Talents of Discipline to Universities(No.D17008).
文摘Reducing the cost of RuO_(2)/TiO_(2)catalysts is still one of the urgent challenges in catalytic HCl oxidation.In the present work,a Ce-doped TiO_(2)supported RuO_(2)catalyst with a low Ru loading was developed,showing a high activity in the catalytic oxidation of HCl to Cl_(2).The results on some extensive characterizations of both Ce-doped TiO_(2)carriers and their supported RuO_(2)catalysts show that the doping of Ce into TiO_(2)can effectively change the lattice parameters of TiO_(2)to improve the dispersion of the active RuO_(2)species on the carrier,which facilitates the production of surface Ru species to expose more active sites for boosting the catalytic performance even under some harsh reaction conditions.This work provides some scientific basis and technical support for chlorine recycling.
基金Project supported by the Key Program of National Natural Science Foundation of China(21336006)the Shanxi Province Scientific and Technological Project(20140313002-2)
文摘The physicochemical properties of Pd and Pd-Pt catalysts which possess different Ce doping position were investigated by techniques of TEM, XRD, N2 adsorption-desorption, XPS and FT-IR. The catalytic performance for methanol total oxidation was examined to study the effects of Ce adding position.CeO2-Al2 O3-TiO2（CAT） catalysts that Ce is directly introduced into support show higher reactivity and CO2 selectivity than CeO2/Al2 O3-TiO2（Ce/AT） samples in which Ce is loaded by impregnation method.The characterization results reveal that the Ce doping position does not cause obvious otherness of basic crystalline phase and mesoporous structure of support. However, the Ce doping position affects the pore shapes of support and then influences the pore diameter. CAT catalysts possess more abundant adsorbed oxygen and more Ti3＋ can transform the more gaseous oxygen into the active oxygen species on the catalyst surface, which is beneficial to the reaction. The Al-O-Ti bridges in CAT facilitate the cooperation of Al and Ti species, which further speeds up the reaction rate.
基金the National Natural Science Foundation of China(Nos.22074137 and 21721003).
文摘Electrochemical nitrogen reduction reaction(NRR)is a promising method for the synthesis of ammonia(NH3).However,the electrochemical NRR process remains a great challenge in achieving a high NH3 yield rate and a high Faradaic efficiency(FE)due to the extremely strong N≡N bonds and the competing hydrogen evolution reaction(HER).Recently,bismuth telluride(Bi_(2)Te_(3))with two-dimensional layered structure has been reported as a promising catalyst for N_(2)fixation.Herein,to further enhance its NRR activity,a general doping strategy is developed to introduce and modulate the crystal defects of Bi_(2)Te_(3)nanosheets by adjusting the amount of Ce dopant(denoted as Ce_(x)-Bi_(2)Te_(3),where x represents the designed molar ratio of Ce/Bi).Meanwhile,the crystal defects can be designed and controlled by means of ion substitution and charge compensation.At−0.60 V versus the reversible hydrogen electrode(RHE),Ce_(0.3)-Bi_(2)Te_(3)exhibits a high NH_(3) yield(78.2μg·h^(−1)·mgcat^(−1)),a high FE(19.3%),excellent structural and electrochemical stability.Its outstanding catalytic activity is attributed to the tunable crystal defects by Ce doping.This work not only contributes to enhancing the NRR activity of Bi_(2)Te_(3)nanosheets,but also provides a reliable approach to prepare high-performance electrocatalysts by controlling the type and concentration of crystal defects for artificial N_(2)fixation.
基金supported by National Key R&D Program of China(No.2022YFB3504700)the National Natural Science Foundation of China(No.92061125)Jiangxi Natural Science Foundation(No.20212ACB213009)。
文摘The V-based body-centered cubic(BCC)-type hydrogen storage alloys have attracted significant attention due to their high theoretical hydrogen storage capacity of3.80 wt%.However,their practical application faces challenges related to low dehydriding capacity and poor activation performance.To overcome these challenges,a BCC-type Ti-V-Cr-Mn-Mo-Ce high-entropy alloy(HEA)with an effectively dehydriding capacity of 2.5 wt% above 0.1 MPa was prepared.By introduction of Mo and conducting heat treatment,the precipitation of Ti-rich phase in HEA was successfully suppressed,resulting in improved compositional uniformity and dehydriding capacity.Consequently,the effective dehydriding capacity increased significantly from 0.60 wt% to 2.50 wt% at 65℃,surpassing that of other types of hydrogen storage alloys under the same conditions.Moreover,the addition of 1 wt%Ce enabled initial hydrogen absorption at 25℃ without the need for activation at 400℃.Furthermore,Ce doping reduced the dehydriding activation energy of the Ti-V-Cr-Mn-Mo-Ce HEA from 52.71 to 42.82 kJ·mol^(-1)Additionally,the enthalpy value of dehydrogenation decreased from 46.89 to 17.96 k J·mol^(-1),attributed to a decrease in the hysteresis factor from 0.68 to 0.52.These findings provide valuable insights for optimizing the hydrogen storage property of HEA.
基金financially supported by the National Key Research and Development Program of China(No.2017YFB0702902)the National Natural Science Foundation of China(No.51471014)。
文摘Isothermal oxidation resistance,oxide scale evolution and failure mechanism of Ce-doped Co-Al-W-MoTa-B alloy(0.01 at%,0.05 at%,0.10 at%and 0.20 at%Ce)exposed at 800℃were compared.The 0.01 Ce and 0.05 Ce alloys were consisted ofγ/γ’coherent micro structure,while theκ-Co_(3)W compound precipitated at the grain boundary of the 0.1 OCe and 0.20 Ce alloys in addition to theγ/γ’microstructure.The oxidation kinetics curves of the Cedoped alloys exhibited a parabolic time dependence on the weight gain.With an increasing nominal Ce content,the weight gain of the Co-Al-W-Mo-Ta-B alloys monotonically decreased.An oxide scale composed of a dense and uniform outer Co_(3)O_(4)+CoO layer,a middle CoAl2 O4 and CoWO4 compound layer and an inner Al_(2)O_(3)layer.The excellent oxidation resistance of 0.2 Ce alloy was mainly attributed to a shorter incubation stage for the formation of the continuous and protective Al_(2)O_(3)layer and the thickest Al_(2)O_(3)layer during entire oxidation process.
基金Project supported by the National Natural Science Foundation of China(41831285,51974261)Doctoral Research Initiation Project(YBZ202127)from Xichang University。
文摘Ce and C-S codoped mesoporous TiO_(2)nanocomposites were synthesized via a sol-gel method integrated with an evaporation-induced self-assembly approach.The basic physicochemical characteristics of the synthetic samples were analyzed via a series of characterization techniques.The results reveal that C-S and Ce codoping on mesoporous TiO_(2)enhances the photocatalytic activity owing to the synergistic effect caused by narrowing the band gap,enhancing adsorption,trapping and transferring the excited e^(-)/h^(+)pairs and suppressing the recombination of e^(-)/h^(+)pairs.Furthermore,the obtained C,S-TiO_(2)/CeO_(2)materials exhibit large specific surface areas and numerous pores which not only effectively improve the adsorption-enrichment capability,but also supply multi-dimensional mass and electron transfer channels.The photodegradation efficiency of RhB by C,S-TiO_(2)/CeO_(2)within 40 min is nearly 100%,and its degradation efficiency is 6.63 times that of undoped TiO_(2).Recycling experiments show that mesoporous C,S-TiO_(2)/CeO_(2)shows excellent recoverability and stability.Furthermore,by trapping experiments,·O_(2)e^(-)/h^(+)and·OH are the predominant active species and a possible reaction mechanism is proposed.
基金Project supported by the National Key Research and Development Program of China(2017YFC0212606,2017YFC0211503,2016YFC0204102)the National Natural Science Foundation of China(51608500)。
文摘Hierarchical ZSM-5(HZ)molecular sieves based on fly ash were synthesized using a method combining water heat treatment with step-by-step calcination.The coupling catalysts between La_(1-x)Ce_(x)Mn_(0.8)-Ni_(0.2)O_(3)(x≤0.5)perovskites and HZ were prepared through the impregnation method,which were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),N_(2)adsorption,X-ray photoelectron spectroscopy(XPS),NH3-temperature programmed desoprtion(NH3-TPD),H_(2)-temperature programmed reduction(H_(2)-TPR)and O_(2)-TPD techniques and investigated regarding pentanal oxidation at 120-390℃to explore the effects of Ce doping on the catalytic activity and the active oxygen species of the coupling catalysts,meanwhile,the reaction mechanism and pathway of pentanal oxidation were also studied.The results reveal that Ce substitution at La sites can change the electronic interactions between all the elements and promote the electronic transfer among La,Ce,Ni,Mn and HZ,influencing directly the physicochemical characteristics of the catalysts.Moreover,the amount and transfer ability of surface adsorbed oxygen(O_(2)-and O-)regarded as the reactive oxygen species and the low temperature reducibility are the main influence factors in pentanal oxidation.Additionally,La_(0.8)Ce_(0.2)Mn_(0.8)Ni_(0.2)O_(3)/HZ exhibits the best catalytic activity and deep oxidation capacity as well as a better water resistance due to its larger amount of surface adsorbed oxygen species and higher low temperature reducibility.What’s more,appropriate Ce substitution can significantly enhance the amount of O_(2)-ions,which can distinctly enhance the catalytic activity of the catalyst,and moderate acid strength and appropriate acid amount can also facilitate the improvement of the pentanal oxidation activity.It is found that there is a synergic catalytic effect between surface acidity and redox ability of the catalyst.According to the in situ DRIFTS and GC/MS analyses,pentanal can be oxidized gradually to CO_(2)and H_(2)O by the surface oxygen species with the form of adsorption in air following the Langmuir-Hinshelwood(L-H)reaction mechanism.Two reaction pathways for the pentanal oxidation process are proposed,and the conversion of the formates to carbonates may be one of the main rate-determining steps.
基金Project supported by the National Key R&D Program of China(2016YFB0600400)National Natural Science Foundation of China(21507075)。
文摘Fe-based catalysts have a great potential to be used for selective catalytic reduction(SCR)of NO_(x)with NH3 reaction due to their low cost,nontoxicity and excellent catalytic activity.The aim of this paper is to investigate Ce doping effect on activity of NH_(3)-SCR over the FeO_(x)/TiO_(2)catalyst.In-situ diffuse reflectance infrared fourier transform(DRIFT)technology was utilized to verity the adsorbed species on the surface of FeO_(x)/TiO_(2)and FeO_(x)-CeO_(2)/TiO_(2)catalysts.With respect to the obtained results,among the four catalysts studied,the FeO_(x)-CeO_(2)/TiO_(2)with the FeO_(x)/CeO_(2)ratio of 3/8 shows the best NO conversion more than 98%in the temperature range of 230—350℃,The active centers for NH_(3)adsorption and activation are assigned to Lewis acid sites over the FeO_(x)-CeO_(2)/TiO_(2)and monodentate nitrates can act as the key intermediate in the NH3-SCR.Moreover,both of Langmuir-Hinshelwood and Eley-Rideal mechanisms are observed over the FeO_(x)-CeO_(2)/TiO_(2)catalysts in the SCR.
基金Project supported by National high Technology Research and Development Program(863 Program)(2012AA030314)
文摘The Ce-TiO2/KL （diatomite） ball photocatalyst was prepared and characterized based on the pretreated diatomite. The resuits showed that comparing with the crude diatomite, proper pretreatment could significantly improve its SiO2 purity and specific surface area. The surface of diatomite was clear with uniform pore structure and big pore size. With diatomite ball as carder, the supported Ce-TiO2/KL ball photocatalyst was prepared by sol-gel method. The photocatalytic performances of the supported Ce-TiO2/ KL ball and Ce-TiO2/KL powder photocatalysts under various preparation conditions were studied in view of photocatalytic degrada- tion rate of Rhodamine B （Rh B） solution. The degradation rate of the ball photocatalysts for Rh B reached 94.6% and could be reused for many times, which showed much better photocatalytic performance and stability than powder photocatalysts.
基金supported by the Fundamental Research Funds for the Central Universities (No.G2022WD01007)the National Natural Science Foundation of China (Nos.11874313,51971081,and 52172194)+1 种基金the Shenzhen Science and Technology Innovation Plan (No.KQTD20200820113045081)State Key Lab of Advanced Welding and Joining,Harbin Institute of Technology.
文摘SnSe exhibits excellent thermoelectric performance in both n-and p-type single crystals,but its n-type polycrystals are restricted because of the lower electrical conductivity.Here,we dually introduced rare earth element Ce and PbTe to optimize the thermoelectric properties of n-type SnSe polycrystals.It is demonstrated that Ce is an effective cationic dopant to convert SnSe from p-to n-type conductor,and an enhanced peak zT value of∼0.9 at 823 K was obtained in Sn 0.97 Ce 0.03 Se due to the improved power factor.Furthermore,PbTe alloying not only reduced the band gap to increase the carrier concentration,but also enhanced the density-of-states effective mass,and hence further increased the power factor in the whole measured temperature range.Meanwhile,the lattice thermal conductivity was significantly reduced owing to the enhanced phonon scattering by the mass and strain fluctuations.As a result,the peak zT value was increased to∼1.3 for Sn 0.9 Pb 0.07 Ce 0.03 Se 0.93 Te 0.07 together with a high average zT value of∼0.52 in the temperature range of 300 to 823 K.
基金financially supported by the National Natural Science Foundation of China(21776314)the Qingdao Science and Technology Benefiting People Special Project(20-3-4-8-nsh)+2 种基金the Fundamental Research Funds for the Central Universities(20CX02212A)the Development Fund of State Key Laboratory of Heavy Oil Processingthe Postgraduate Innovation Project of China University of Petroleum(YCX2020046)。
文摘The intrinsic activity of Co(OH)_(2) for oxygen evolution reaction(OER)may be elaborately improved through the suitable valence adjustment.Ce modification at electronic level is proved to be an efficient strategy owing to the flexible transformation of Ce^(3+)/Ce4+.Herein,Ce0.21@Co(OH)_(2) with the optimized Ce doping have been fabricated to tailor the fast electron transfer for the enhanced activity and stability for OER.Firstly,the obtained core-shell structure composed of vertical loose Co(OH)_(2) sheets not only exposes a large number of active sites,but also provides channels for Ce doping.Secondly,the high pressure microwave with instantaneous heating can fast introduce Ce into Co(OH)_(2),obtaining Cex@Co(OH)_(2) with well dispersion and close integration.The intimated interaction between Ce and Co species may provide the"d-f electronic ladders"for accelerating electron transfer of the catalytic surface.Meanwhile,Ce promotes the formation of Co-superoxide intermediate and/or the release of oxygen,which is considered to be the rate-determining step for OER.The electrochemical measurements confirmed the low overpotential of 300 m V at 10 m A cm^(-2) and great stability of Ce0.21@Co(OH)_(2) for OER.This work demonstrates a meaningful approach to realize the tuned electronic structure through metal doping.
基金This work was supported by the National Key Research and Development Program of China(No.2016YFB0600603).
文摘In order to improve the ability of SCR catalyst to catalyze the oxidation of gaseous elemental mercury,a series of novel Ce modified SCR(Selection Catalytic Reduction,V_(2)O_(5)-WO_(3)/TiO_(2))catalysts were prepared via two-step ultrasonic impregnation method.The performance of Ce/SCR catalysts on Hg^(0)oxidation and NO reduction as well as the catalytic mechanism on Hg^(0)oxidation was also studied.The XRD,BET measurements and XPS were used to characterize the catalysts.The results showed that the pore volume and pore size of catalyst was reduced by Ce doping,and the specific surface area decreased with the increase of Ce content in catalyst.The performance on Hg^(0)oxidation was promoted by the introduction of CeO_(2).Ce_(1)/SCR(1%Ce,wt.%)catalyst exhibited the best Hg^(0)oxidation activity of 21.2%higher than that of SCR catalyst at 350℃,of which the NO conversion efficiency was also higher at 200-400℃.Furthermore,Ce_(1)/SCR showed a better H_(2)O resistance but a slightly weaker SO_(2)resistance than SCR catalyst.The chemisorbed oxygen and weak absorbed oxygen on the surface of catalyst were increased by the addition of CeO_(2).The chemisorbed oxygen and weak absorbed oxygen on the surface of catalyst were increased by the addition of CeO_(2).The Ce_(1)/SCR possed better redox ability compared with SCR catalyst.HCl was the most effective gas responsible for the Hg^(0)oxidation,and the redox cycle(V^(4+)+Ce^(4+)←→V^(5+)+Ce^(3+))played an important role in promoting Hg^(0)oxidation.
基金Project supported by the Polish National Science Centre(2015/17/N/ST5/01947)
文摘A series of KY3F10 nanophosphors doped with Gd3＋, Ce3＋ and Eu3＋ ions were obtained with the use of a co-precipitation method. The resulting products were white precipitates, consisting of spherical particles with diameter about 150-200 nm, which was confirmed using transmission electron microscopy （TEM） technique. Powder X-ray diffraction （XRD） and energy dispersive X-ray analysis （EDX） measurements confirmed appropriate structures of the nanoparticles obtained. Spectroscopic properties of the prod- ucts were examined on the basis of the measured excitation/emission spectra and luminescence decay curves. The synthesized sam- ples showed orange-red luminescence, characteristic for Eu3＋ ions. The reaction process was performed in required alkaline pH ad- justed with the use of ethylenediaminetetraacetic acid （EDTA） and potassium hydroxide. The samples containing large amounts of Gd3＋ dooant ions exhibited a tendencv to form nroducts with different momhologies.
基金supported by the National Natural Science Foundation of China (Grant No. 60578041)the Shanghai Leading Academic Disciplines (Grant No. S30107)
文摘Ce3＋-doped yttrium lanthanum oxide （Y0.9La0.1）2O3 transparent ceramics is fabricated with nanopowders and sintered in H2 atmosphere. The spectral properties of Ce：（Y0.9La0.1）2O3 transparent ceramics are investigated. There appear two characteristic absorption peaks of Ce3＋ ions at 230~nm and 400~nm, separately. It is found that Ce3＋ ions can efficiently produce emission at 384~nm from （Y0.9La0.1）2O3 transparent ceramic host, while the emission is completely quenched in Re2O3 （Re=Y, Lu, La） host materials.
文摘Thispaperisconcerned withthe preparation ofcerium doped yttrium iron garnet which areknown to be an oxide withlarge magneto opticaleffect. Usingtheimproved flux method wesuccessfully grew the bulksinglecrystalsofiron garnet doped by Ce 3 + ions with maximum substitution upto0 349. Here weinvestigatedthedifferentcomposition ofsolution for maxi mum Ce3 + substitution. Thespectra ofthe Faraday rotation andtheoptical absorption were measured inthenearinfrared region fordifferentCe3 + ionsdopediron garnets. The Cesub stitution prominentlyenhancesthe Faradayeffect,andthe Yb and Euionssubstitutefor Yinthe dodecahedralsitesof YIGcanincreasetheconcentration of Ce3 + ions, depresstheforma tion of nonmagnetic Ce4 + ionsbythechargecompensation.
基金support from the National Natural Science Foundation of China(No.52272093)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province(No.2022C01189).
文摘Solid-state sodium batteries (SSSBs) are gaining significant attention for their potential in electrochemical energy storage. However, the development of SSSBs is hindered by the low ionic conductivity of sodium-ion solid electrolytes (SSEs). Herein, Ce with a relatively large ionic radius is employed to replace Zr in Na_(3)Zr_(2)Si_(2)PO_(12) (NZSP), aiming to increase the ionic conductivity of the SSEs. Through structural analysis and theoretical calculations, it is inferred that Ce doping is favorable for stabilizing phases with higher ionic conductivity, increasing the Na^(+) concentration via the substitution of Zr^(4+) with Ce^(3+), and facilitating the generation of a densified microscopic morphology. The Ce-doped NZSP achieves a high room-temperature conductivity of 2.08 mS·cm^(−1) and good interfacial compatibility with Na metal. Furthermore, the assembled Na_(3)V2(PO4)3 cell based on Ce-doped NZSP maintains a capacity of 111.18 mAh·g^(−1) at 0.5 C after 200 cycles, with a high retention of 98.06%.
基金supported from the Natural Science Foundation of Guangdong Province(2023B1515040005)the State Key Laboratory of Pulp and Paper Engineering(2022PY05)the National Natural Science Foundation of China(22138003,21825802)
文摘The electrooxidation of 5-hydroxymethylfurfural(HMFOR)not only offers a green route to attain high-value 2,5-furandicarboxylic acid(FDCA)from biomass,but also is considered as a promising approach to replace the kinetically sluggish OER for future hydrogen production.Herein,we report the construction and structural optimization of Ce-doped ultrasmall Co_(2)P nanoparticles(NPs)in carbon-based nanoarrays to boost HER-coupled HMFOR.We demonstrate that the electronic structure of Co-based electrocatalysts can be positively regulated by Ce doping and the optimized Ce-Co_(2)P-based electrocatalyst only require a low voltage of 1.20 V vs.RHE to achieve 10 m A cm^(-2)for HMFOR with an excellent FDCA Faraday efficiency(FEFDCA)of 98.5%,which are superior to its Ce-free counterpart(1.29 V vs.RHE;FEFDCA=83.9%).When being assembled into a HERcoupled HMFOR system,this bifunctional electrocatalyst can achieve 50 m A cm^(-2)with an ultralow voltage of 1.46 V,which is reduced by 210 m Vas compared with that of its Ce-free counterpart(1.67 V).Quasi-operando experiments and DFTcalculations further reveal the significant roles of Ce doping in promoting the charge transfer between active sites and HMF,and reducing the free energy barrier of intermediate(^(*)HMFCA)dehydrogenation.This study provides new insights into the underlying mechanisms of Ce doping into metal phosphides for boosting HER-coupled HMFOR,developing a facile methodology to construct efficient electrocatalysts for energy storage/conversion systems.
