Machine learning combined with density functional theory(DFT)enables rapid exploration of catalyst descriptors space such as adsorption energy,facilitating rapid and effective catalyst screening.However,there is still...Machine learning combined with density functional theory(DFT)enables rapid exploration of catalyst descriptors space such as adsorption energy,facilitating rapid and effective catalyst screening.However,there is still a lack of models for predicting adsorption energies on oxides,due to the complexity of elemental species and the ambiguous coordination environment.This work proposes an active learning workflow(LeNN)founded on local electronic transfer features(e)and the principle of coordinate rotation invariance.By accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures,LeNN mitigates abrupt feature changes due to different element types and clarifies coordination environments.As a result,it enables the prediction of^(*)H adsorption energy on binary oxide surfaces with a mean absolute error(MAE)below 0.18 eV.Moreover,we incorporate local coverage(θ_(l))and leverage neutral network ensemble to establish an active learning workflow,attaining a prediction MAE below 0.2 eV for 5419 multi-^(*)H adsorption structures.These findings validate the universality and capability of the proposed features in predicting^(*)H adsorption energy on binary oxide surfaces.展开更多
The effects of support materials on catalytic performance were investigated in catalytic removal of toluene.And the Mn–Ce binary oxides as active components were supported on ZrO_(2),SiO_(2),γ-Al_(2)O_(3) and TiO_(2...The effects of support materials on catalytic performance were investigated in catalytic removal of toluene.And the Mn–Ce binary oxides as active components were supported on ZrO_(2),SiO_(2),γ-Al_(2)O_(3) and TiO_(2) support materials.Many techniques,including X-ray diffraction(XRD),Brunauer–Emmett–Teller method(BET),X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction(TPR)and NH_(3)-temperature-programmed desorption(NH_(3)-TPD),were used to characterize physicochemical properties.Among the different catalysts,the MnCe/ZrO_(2) catalyst with the lowest specific surface area(39.7 m^(2)/g)shows the best catalytic activity.In terms of toluene conversion,the activity order is as follows:MnCe/ZrO_(2)>MnCe/TiO_(2)≈MnCe/SiO_(2)>MnCe/Al_(2)O_(3).The better performance of MnCe/ZrO_(2) should be attributed to the low-temperature reducibility,and abundant surface species(Mn^(4+)and lattice oxygen).And XPS and TPR results reveal that more surface abundant Mn and Ce elements generate good interaction in MnCe/ZrO_(2).The weak interaction between metal oxide and support also boosts the dispersion and complete reduction of MnCe oxides at low temperature.In addition,the in-situ DRIFTS results clarify that the carbonate species are main intermediates in MnCe/ZrO_(2) sample during surface reaction process.展开更多
This paper establishes a new model for calculation of the standard entropies of solid binary oxides as follows: S_(29)=27.07×Φ_1+1.120×Φ_2+n_1×k×Φ, -22.19 e.u (R=0.9960) We have invesigated 103 ...This paper establishes a new model for calculation of the standard entropies of solid binary oxides as follows: S_(29)=27.07×Φ_1+1.120×Φ_2+n_1×k×Φ, -22.19 e.u (R=0.9960) We have invesigated 103 binary oxides. and found good agreemenl between estimated and experimental entropies.展开更多
The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. ...The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. The molar ratio of Fe and Mn in the synthetic Fe-Mn binary oxides was 4 ： 3. The FM-1 and FM-2（prepared at different activation temperatures） having high specific surface areas（358.87 and 128.58 m^2/g, respectively） were amorphous and of nano particle types. The amount of arsenic adsorbed on FM-1 was higher than that adsorbed on FM-2 particles. After adsorption by FM-1, residual arsenic concentration decreased to less than 10 μg/L. The adsorption kinetics data were analyzed using different kinetic models including pseudo first-order model, pseudo second-order model, Elovich model and intraparticle diffusion model. Pseudo second-order kinetic model was the most appropriate model to describe the adsorption kinetics. The adsorption percentage of As（Ⅲ） increased in the p H range of 2–3 while it decreased with the increase of pH（ 3〈pH〈10）. The effects of coexisting anions on As（Ⅲ） removal using FM-1 and FM-2 were also studied and the order of the effects is as follows： NO_3^-, Cl-, F-〈SO_4^（2-）, HCO_3-〈H_2PO_4^-, indicating that H_2PO_4^- is the major competitor with As（Ⅲ） for adsorptive sites on the surface of the adsorbents. The higher adsorption capacity of FM-1 makes it potentially attractive adsorbent for the removal of As（Ⅲ） from groundwater.展开更多
TiO_2 modified Al_2O_3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO_2–Al_2O_3catalyst in CO_2 methanation reaction was inv...TiO_2 modified Al_2O_3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO_2–Al_2O_3catalyst in CO_2 methanation reaction was investigated. Compared with Ru/Al_2O_3 catalyst, the Ru/TiO_2–Al_2O_3catalytic system exhibited a much higher activity in CO_2 methanation reaction. The reaction rate over Ru/TiO_2–Al_2O_3 was 0.59 mol CO_2·(g Ru)1·h-1, 3.1 times higher than that on Ru/Al_2O_3[0.19 mol CO_2·(gRu)-1·h-1]. The effect of TiO_2 content and TiO_2–Al_2O_3calcination temperature on catalytic performance was addressed. The corresponding structures of each catalyst were characterized by means of H_2-TPR, XRD, and TEM. Results indicated that the averaged particle size of the Ru on TiO_2–Al_2O_3support is 2.8 nm, smaller than that on Al_2O_3 support of 4.3 nm. Therefore, we conclude that the improved activity over Ru/TiO_2–Al_2O_3catalyst is originated from the smaller particle size of ruthenium resulting from a strong interaction between Ru and the rutile-TiO_2 support, which hindered the aggregation of Ru nanoparticles.展开更多
Three different Ti-Si oxide structuares, silica supported titania, silica coated titania and intimately mixed silicatitania, containing 10%-40% SiO2, were made by sol-gel process. The variations of microstructure para...Three different Ti-Si oxide structuares, silica supported titania, silica coated titania and intimately mixed silicatitania, containing 10%-40% SiO2, were made by sol-gel process. The variations of microstructure parameters of nanocrystalline （nc） TiO2-anatase in the three kirds of binary oxides, including in-plane spacing d, cell constants （ao, co）, cell volume V, cell axial ratio co/ao and crystal grain size, were comparatively investigated by high resolution transmission electron microscopy （HRTEM） and X-ray diffraction （XRD）. It is found that the microstructure parameters vary remarkably with increasing SiO2 content and annealing temperature. Different structured Ti-Si binary oxides lead to different variation tendencies of microstructure parameters. The more SiO2 the binary oxide contains, the more lattice defects of nc TiO2-anatase appear; diffusion or migration of Si cations could be an important influential factor in the variations of microstructure. The grain size of nc TiO2 in the three kinds of binary oxides not only depends on SiO2 content and annealing temperature but also on the degree of lattice microstrain and distortion of nc TiO2-anatase. Both grain size and phase transformation of nc TiO2-anatase are effectively inhibited with increasing SiO2 content.展开更多
Following publication of the original article[1],the authors found that they pasted the same data when drawing XRD for sample NCO-1 and NCO-2 in Fig.2a,however,the XRD of all four samples in the manuscript was tested,...Following publication of the original article[1],the authors found that they pasted the same data when drawing XRD for sample NCO-1 and NCO-2 in Fig.2a,however,the XRD of all four samples in the manuscript was tested,and XRD raw data were kept and can be offered.The correct Fig.2 has been provided in this Correction.展开更多
Ferroelectric HfO_(2)-based materials and devices show promising potential for applications in information technology but face challenges with inadequate electrostatic control,degraded reliability,and serious variatio...Ferroelectric HfO_(2)-based materials and devices show promising potential for applications in information technology but face challenges with inadequate electrostatic control,degraded reliability,and serious variation in effective oxide thickness scaling.We demonstrate a novel interface-type switching strategy to realize ferroelectric characteristics in atomic-scale amorphous binary oxide films,which are formed in oxygen-deficient conditions by atomic layer deposition at low temperatures.This approach can avoid the shortcomings of reliability degradation and gate leakage increment in scaling polycrystalline doped HfO_(2)-based films.Using theoretical modeling and experimental characterization,we show the following.(1)Emerging ferroelectricity exists in ultrathin oxide systems as a result of microscopic ion migration during the switching process.(2)These ferroelectric binary oxide films are governed by an interface-limited switching mechanism,which can be attributed to oxygen vacancy migration and surface defects related to electron(de)trapping.(3)Transistors featuring ultrathin amorphous dielectrics,used for non-volatile memory applications with an operating voltage reduced to±1 V,have also been experimentally demonstrated.These findings suggest that this strategy is a promising approach to realizing next-generation complementary metal-oxide semiconductors with scalable ferroelectric materials.展开更多
Although the Ostwald ripening approach is often utilized to manufacture single hollow metal oxide,constructing hollow binary oxide heterostructures as potent photoelectrochemical(PEC)catalysts is still obscure and cha...Although the Ostwald ripening approach is often utilized to manufacture single hollow metal oxide,constructing hollow binary oxide heterostructures as potent photoelectrochemical(PEC)catalysts is still obscure and challenging.Herein,we reveal a general strategy for fabricating hollow binary oxides heterostructures(Co_(3)O_(4)-δ-MnO_(2)and Co_(3)O_(4)–SnO_(2))utilizing Ostwald ripening.Hollow Co_(3)O_(4)-δ-MnO_(2)nano-network with the structure evolution process was systematically explored through experimental and theoretical tools,identifying the origin of hollow binary oxides due to the interfaces acting as landing sites for their growth.In addition,the structural evolution,from hollow Co_(3)O_(4)-δ-MnO_(2)to Co_(3)O_(4)-α-MnO_(2),can be observed when the time of secondary hydrothermal reaches 96 h due to the topotactic layer-to-tunnel transition process.Notably,optimized Co_(3)O_(4)-δ-MnO_(2)-48 exhibits a superior PEC degradation efficiency of 96.42%and excellent durability(20,000 min)under harsh acid conditions,attributed to the massive hollow structures'vast surface area for high intently active species.Furthermore,density functional theory simulations elucidated the Co_(3)O_(4)-δ-MnO_(2)’electron-deficient surface and high d-band center(Co_(3)O_(4)-δ-MnO_(2),-1.06;Co_(3)O_(4)-α-MnO_(2),-1.49),strengthening the interaction between the catalyst's surface and active species and prolonging the lifetime of active species ofO_(2)and 1 O_(2).This work not only demonstrates superior PEC degradation efficiency of hollow Co_(3)O_(4)-δ-MnO_(2)for practical use but also lays the cornerstone for constructing hollow binary oxides heterostructures through Ostwald ripening.展开更多
Significant concerns have been raised over the presence of antibiotics including tetracyclines in aquatic environments.A series of FeMn binary oxide with different Fe：Mn molar ratios was synthesized by a simultaneous...Significant concerns have been raised over the presence of antibiotics including tetracyclines in aquatic environments.A series of FeMn binary oxide with different Fe：Mn molar ratios was synthesized by a simultaneous oxidation and coprecipitation process for TC removal.Results showed that Fe-Mn binary oxide had higher removal efficiency than that of hydrous iron oxide and hydrous manganese oxide,and that the oxide with a Fe：Mn molar ratio of 5：1 was the best in removal than other molar ratios.The tetracycline removal was highly pH dependent.The removal of tetracycline decreased with the increase of initial concentration,but the absolute removal quantity was more at high concentration.The presence of cations and anions such as Ca2＋,Mg2＋,CO32-and SO42-had no significant effect on the tetracycline removal in our experimental conditions,while SiO32-and PO43-had hindered the adsorption of tetracycline.The mechanism investigation found that tetracycline removal was mainly achieved by the replacement of surface hydroxyl groups by the tetracycline species and formation of surface complexes at the water/oxide interface.This primary study suggests that Fe-Mn binary oxide with a proper Fe：Mn molar ratio will be a very promising material for the removal of tetracycline from aqueous solutions.展开更多
A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO)sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As)and cadmium (Cd) in water.The maximum As(Ⅲ)...A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO)sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As)and cadmium (Cd) in water.The maximum As(Ⅲ) and Cd(Ⅱ) adsorption capacities of 1%CaSFMBO were 156.25 mg/g and 107.53 mg/g respectively in single-adsorption systems.The adsorption of As and Cd by the Ca-SFMBO sorbent was pH-dependent at values from 1 to 7,with an optimal adsorption pH of 6.In the dual-adsorbate system,the presence of Cd(Ⅱ) at low concentrations enhanced As(Ⅲ) adsorption by 33.3%,while the adsorption of As(Ⅲ) was inhibited with the increase of Cd(Ⅱ) concentration.Moreover,the addition of As(Ⅲ) increased the adsorption capacity for Cd(Ⅱ) up to two-fold.Through analysis by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR),it was inferred that the mechanism for the co-adsorption of Cd(Ⅱ) and As(Ⅲ) included both competitive and synergistic effects,which resulted from the formation of ternary complexes.The results indicate that the Ca-SFMBO material developed here could be used for the simultaneous removal of As(Ⅲ) and Cd(Ⅱ) from contaminated water.展开更多
Considering the different geochemical enrichment behaviors of W and Mo,Fe?Mn binary oxide(FMBO),ferric hydroxide(Fe(OH)3)and manganese dioxide(MnO2)were studied to separate W from molybdate solution,respectively.The e...Considering the different geochemical enrichment behaviors of W and Mo,Fe?Mn binary oxide(FMBO),ferric hydroxide(Fe(OH)3)and manganese dioxide(MnO2)were studied to separate W from molybdate solution,respectively.The experimental results demonstrated that Fe?Mn binary oxide(FMBO)was the most suitable adsorbent for the separation.Under a wide pH(6.9?11.3)region,more than80%W removal efficiency and less than3%Mo loss could be obtained.In addition,the Fe?Mn binary oxide adsorbent can be regenerated by treating with3mol/L NaOH,and the W adsorption efficiency was retained after five adsorption?desorption?regeneration cycles.All these indicate that the Fe?Mn binary oxides have the potential for the separation of W from molybdate solution.展开更多
Binary metal oxide（MnOx-A/TiO2）catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide（TiO2）,where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 sele...Binary metal oxide（MnOx-A/TiO2）catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide（TiO2）,where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 selectivity,and SO2 poisonous tolerance were investigated.The catalytic performance at low temperatures decreased in the following order：Mn-W/TiO2〉Mn-Fe/TiO2〉Mn-Cr/TiO2〉Mn-Mo/TiO2,whereas the N2 selectivity decreased in the order：Mn-Fe/TiO2〉Mn-W/TiO2〉Mn-Mo/TiO2〉Mn-Cr/TiO2.In the presence of 0.01%SO2 and 6%H2O,the NOx conversions in the presence of Mn-W/TiO2,Mn-Fe/TiO2,or Mn-Mo/TiO2 maintain 98.5%,95.8%and 94.2%, respectively,after 8 h at 120°C at GHSV 12600 h？ 1 .As effective promoters,WO3 and Fe2O3 can increase N2 selectivity and the resistance to SO2 of MnOx/TiO2 significantly.The Fourier transform infrared（FTIR）spectra of NH3 over WO3 show the presence of Lewis acid sites.The results suggest that WO3 is the best promoter of MnOx/TiO2,and Mn-W/TiO2 is one of the most active catalysts for the low temperature selective catalytic reduction of NO with NH3.展开更多
Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP i...Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate,which needs to be addressed by introducing catalysts.Therefore,the design and optimization of catalysts have become the focus of NTP coupling catalysis research.In thiswork,a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system.Among them,Co_(2)Ni_(1)O_(x)achieves 60%carbon dioxide(CO_(2))selectivity(SCO_(2))when the benzene removal efficiency(REbenzene)reaches more than 99%,which is a significant enhancement compared with the CO_(2)selectivity obtained without any catalysts(38%)under the same input power.More intriguingly,this SCO_(2)is also significantly higher than that of single metal oxides,NiO or Co_(3)O_(4),which is only around 40%.Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co_(2)Ni_(1)O_(x)catalyst.The introduction of Co_(2)Ni_(1)O_(x)was found to promote the generation of acrolein significantly,one of the key intermediates found in NTP alone system reported previously,suggest the benzene ring open reaction is promoted.Compared with monometallic oxides NiO and Co_(3)O_(4),Co_(2)Ni_(1)O_(x)also shows higher active oxygen proportion,better oxygenmobility,and stronger low-temperature redox capability.The above factors result in the improved catalytic performance of Co_(2)Ni_(1)O_(x)in the NTP coupling removal of benzene.展开更多
Cerium dioxide has a comparatively lower Ce4+/Ce3+redox pair,which leaves abundant oxygen vacancies on oxide lattice,also making incorporation of foreign ion and subsequent applications feasible and convenient.In this...Cerium dioxide has a comparatively lower Ce4+/Ce3+redox pair,which leaves abundant oxygen vacancies on oxide lattice,also making incorporation of foreign ion and subsequent applications feasible and convenient.In this work,a series of cerium-yttrium mixed oxides were prepared by using polyvinylpyrrolidone as major template through sol-gel,which were further employed as catalyst for dehydration of aniline with formic acid into N-phenylformamide.Characterizations reveal that synthetic samples have a variety of morphologies including nanoparticle,microflower,and uniform microrods.The monitoring of particle size,zeta potential,and ultravioletvisible(UV-Vis)of preparative solution indicate that selfassembly of polyvinylpyrrolidone and its subsequent reaction with metal ion determines sample morphology.In catalytic dehydration,all samples show high dehydration efficiencies that are comparable to those from anhydrous Na2SO4 and combination of dicyclohexylcarbodiimide with 4-dimethylaminopyridine and dichloromethane shows better outputs than water.In association with structural analysis,cerium looks more active than yttrium,while yttrium mainly plays as a structure-directing and poreformingagent.Thisstudymaycontributeto micro-/nanofabrication of rare earth composites and their catalytic applications.展开更多
To confirm sub-regular solution model valid for predicting the activity of component in binary oxide systems, seven systems in the whole concentration and twelve systems presenting saturation concentration have been s...To confirm sub-regular solution model valid for predicting the activity of component in binary oxide systems, seven systems in the whole concentration and twelve systems presenting saturation concentration have been studied. The total average relative errors of component 1 and 2 are 3.2 % and 4.1% respectively by application of the sub-regular solution model into the systems within the whole concentration. However, the total average relative errors are 16 % and 1088 % in the systems presenting saturation concentration. The results show that sub-regular solu- tion model is not good for predicting the systems presenting saturation concentration, especially for the systems con- taining acidic or neutral oxide. The reason may be that the influence of the two types of oxide on the configuration is greater in binary oxide systems. These oxides can be present in the form of complex anion partly, Si-O, Al-O, Ti-O and so on, for example （SiO4）4-. That is contrary to sub-regular solution model which is supposed that the oxide systems consist of cation and O2-. But compared with regular solution model and quasi-regular solution model, sub- regular solution model is closer to the characteristics of actual solution and the calculated results are superior.展开更多
Environmental risks posed by discharge of the emerging contaminant antimony(Sb) into water bodies have raised global concerns recently.The toxicity of Sb has been shown to be species-dependent,with Sb(Ⅲ) demonstratin...Environmental risks posed by discharge of the emerging contaminant antimony(Sb) into water bodies have raised global concerns recently.The toxicity of Sb has been shown to be species-dependent,with Sb(Ⅲ) demonstrating much greater toxicity than Sb(V).Here,we proposed an electrochemical filtration system to achieve rapid detoxification of Sb(Ⅲ) via a non-radical pathway.The key to this technology was an electroactive carbon nanotube filter functionalized with nanoscale Ti-Ce binary oxide.Under an electric field,in situ generated H_(2) O_(2) could react with the Ti-Ce binary oxide to produce hydroperoxide complexes,which enabled an efficient transformation of Sb(Ⅲ) to the less toxic Sb(V)(τ<2 s) at neutral pH.The impact of important operational parameters was assessed and optimized,and system efficacy could be maintained over a wide pH range and long-term operation.An optimum detoxification efficiency of> 90% was achieved using lake water spiked with Sb(Ⅲ) at 500 μg/L.The results showed that Ti/Ce-hydroperoxo surface complexes were the dominant species responsible for the non-radical oxidation of Sb(Ⅲ) based on extensive experimental evidences and advanced characterizations.This study provides a robust and effective strategy for the detoxification of water containing Sb(Ⅲ) and other similar heavy metal ions by integrating state-of-the-art advanced oxidation processes,electrochemistry and nano-filtration technology.展开更多
Tube-type CO_2 gas sensors based on NASICON (Na Super Ion Conductor) material were fabricated.The material was synthesized by conventional sol-gel method,and the resulted powders were characterized by XRD.The tube-typ...Tube-type CO_2 gas sensors based on NASICON (Na Super Ion Conductor) material were fabricated.The material was synthesized by conventional sol-gel method,and the resulted powders were characterized by XRD.The tube-type CO_2 sensor was prepared with the sensing electrode Li_2CO_3-BaCO_3 binary carbonates in molar ratio 1:1.5.The concentration of CO_2 range from 300μg/g to 3000μg/g,the sensitivity of the sensor was 62.3 mV/decade.The response and recovery time (90%)corresponding to the switching change between 300μg/g and 1000μg/g CO_2 were 20 s and 2 min,respectively.If the sensing electrode was modified with binary oxides,the steady time of the sensor could be greatly reduced from 30 min to 5 min and the stability and humid-resistance of the sensor were improved.展开更多
Binary oxide catalysts with various weight percentage V2O5 loadings were prepared by solid‐state dispersion and the nanocomposites were modified with surfactants. The catalysts were analyzed using X‐ray diffraction,...Binary oxide catalysts with various weight percentage V2O5 loadings were prepared by solid‐state dispersion and the nanocomposites were modified with surfactants. The catalysts were analyzed using X‐ray diffraction, diffuse‐reflectance spectroscopy, Fourier‐transform infrared spectroscopy, scanning electron microscopy, and N2 adsorption‐desorption. The photocatalytic activities of the catalysts were evaluated in the degradation of 2,4‐dichlorophenol under ultraviolet irradiation. The photocatalytic activity of 50 wt%V2O5‐TiO2 （50V2O5‐TiO2） was higher than those of pure V2O5, TiO2, and P25. Interactions between V2O5 and TiO2 affected the photocatalytic efficiencies of the binary oxide catalysts. Cetyltrimethylammonium bromide （CTAB） and hexadecyltrimethylammonium bromide （HTAB） significantly enhanced the efficiency of the 50V2O5‐TiO2 catalyst. The highest per‐centage of 2,4‐dichlorophenol degradation （100%） and highest reaction rate （2.22 mg/（L·min）） were obtained in 30 min with the （50V2O5‐TiO2）‐CTAB catalyst. It is concluded that the addition of a surfactant to the binary oxide significantly enhanced the photocatalytic activity by modifying the optical and electronic properties of V2O5 and TiO2.展开更多
The catalyst screening tests for carbon dioxide oxidative coupling of methane (CO2-OCM) have been investigated over ternary and binary metal oxide catalysts. The catalysts are prepared by doping MgO- and CeO2-based so...The catalyst screening tests for carbon dioxide oxidative coupling of methane (CO2-OCM) have been investigated over ternary and binary metal oxide catalysts. The catalysts are prepared by doping MgO- and CeO2-based solids with oxides from alkali (Li2O), alkaline earth (CaO), and transition metal groups (WO3 or MnO). The presence of the peroxide (O2-2) active sites on the Li2O2, revealed by Raman spectroscopy, may be the key factor in the enhanced performance of some of the Li2O/MgO catalysts. The high reducibility of the CeO2 catalyst, an important factor in the CO2-OCM catalyst activity, may be enhanced by the presence of manganese oxide species. The manganese oxide species increases oxygen mobility and oxygen vacancies in the CeO2 catalyst. Raman and Fourier Transform Infra Red (FT-IR) spectroscopies revealed the presence of lattice vibrations of metal-oxygen bondings and active sites in which the peaks corresponding to the bulk crystalline structures of Li2O, CaO, WO3 and MnO are detected. The performance of 5%MnO/15%CaO/CeO2 catalyst is the most potential among the CeO2-based catalysts, although lower than the 2%Li2O/MgO catalyst. The 2%Li2O/MgO catalyst showed the most promising C2+ hydrocarbons selectivity and yield at 98.0% and 5.7%, respectively.展开更多
基金supported by the National Natural Science Foundation of China(No.52488201)the Natural Science Basic Research Program of Shaanxi(No.2024JC-YBMS-284)+1 种基金the Key Research and Development Program of Shaanxi(No.2024GHYBXM-02)the Fundamental Research Funds for the Central Universities.
文摘Machine learning combined with density functional theory(DFT)enables rapid exploration of catalyst descriptors space such as adsorption energy,facilitating rapid and effective catalyst screening.However,there is still a lack of models for predicting adsorption energies on oxides,due to the complexity of elemental species and the ambiguous coordination environment.This work proposes an active learning workflow(LeNN)founded on local electronic transfer features(e)and the principle of coordinate rotation invariance.By accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures,LeNN mitigates abrupt feature changes due to different element types and clarifies coordination environments.As a result,it enables the prediction of^(*)H adsorption energy on binary oxide surfaces with a mean absolute error(MAE)below 0.18 eV.Moreover,we incorporate local coverage(θ_(l))and leverage neutral network ensemble to establish an active learning workflow,attaining a prediction MAE below 0.2 eV for 5419 multi-^(*)H adsorption structures.These findings validate the universality and capability of the proposed features in predicting^(*)H adsorption energy on binary oxide surfaces.
基金Project supported by the National Natural Science Foundation of China (21503184)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (18KJA610004)。
文摘The effects of support materials on catalytic performance were investigated in catalytic removal of toluene.And the Mn–Ce binary oxides as active components were supported on ZrO_(2),SiO_(2),γ-Al_(2)O_(3) and TiO_(2) support materials.Many techniques,including X-ray diffraction(XRD),Brunauer–Emmett–Teller method(BET),X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction(TPR)and NH_(3)-temperature-programmed desorption(NH_(3)-TPD),were used to characterize physicochemical properties.Among the different catalysts,the MnCe/ZrO_(2) catalyst with the lowest specific surface area(39.7 m^(2)/g)shows the best catalytic activity.In terms of toluene conversion,the activity order is as follows:MnCe/ZrO_(2)>MnCe/TiO_(2)≈MnCe/SiO_(2)>MnCe/Al_(2)O_(3).The better performance of MnCe/ZrO_(2) should be attributed to the low-temperature reducibility,and abundant surface species(Mn^(4+)and lattice oxygen).And XPS and TPR results reveal that more surface abundant Mn and Ce elements generate good interaction in MnCe/ZrO_(2).The weak interaction between metal oxide and support also boosts the dispersion and complete reduction of MnCe oxides at low temperature.In addition,the in-situ DRIFTS results clarify that the carbonate species are main intermediates in MnCe/ZrO_(2) sample during surface reaction process.
文摘This paper establishes a new model for calculation of the standard entropies of solid binary oxides as follows: S_(29)=27.07×Φ_1+1.120×Φ_2+n_1×k×Φ, -22.19 e.u (R=0.9960) We have invesigated 103 binary oxides. and found good agreemenl between estimated and experimental entropies.
基金supported by the National Natural Science Foundation of China(No.41120124003)the Ministry of Science and Technology of China(No.2012AA062602)the 111 project and Priority Development Projects of SRFDP of the Ministry of Education of China
文摘The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides（FM） was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. The molar ratio of Fe and Mn in the synthetic Fe-Mn binary oxides was 4 ： 3. The FM-1 and FM-2（prepared at different activation temperatures） having high specific surface areas（358.87 and 128.58 m^2/g, respectively） were amorphous and of nano particle types. The amount of arsenic adsorbed on FM-1 was higher than that adsorbed on FM-2 particles. After adsorption by FM-1, residual arsenic concentration decreased to less than 10 μg/L. The adsorption kinetics data were analyzed using different kinetic models including pseudo first-order model, pseudo second-order model, Elovich model and intraparticle diffusion model. Pseudo second-order kinetic model was the most appropriate model to describe the adsorption kinetics. The adsorption percentage of As（Ⅲ） increased in the p H range of 2–3 while it decreased with the increase of pH（ 3〈pH〈10）. The effects of coexisting anions on As（Ⅲ） removal using FM-1 and FM-2 were also studied and the order of the effects is as follows： NO_3^-, Cl-, F-〈SO_4^（2-）, HCO_3-〈H_2PO_4^-, indicating that H_2PO_4^- is the major competitor with As（Ⅲ） for adsorptive sites on the surface of the adsorbents. The higher adsorption capacity of FM-1 makes it potentially attractive adsorbent for the removal of As（Ⅲ） from groundwater.
基金Supported by the National Natural Science Foundation of China(211031735127108721476226 and 51471076)DICP Fundamental Research Program for Clean Energy(DICPM201307)
文摘TiO_2 modified Al_2O_3 binary oxide was prepared by a wet-impregnation method and used as the support for ruthenium catalyst. The catalytic performance of Ru/TiO_2–Al_2O_3catalyst in CO_2 methanation reaction was investigated. Compared with Ru/Al_2O_3 catalyst, the Ru/TiO_2–Al_2O_3catalytic system exhibited a much higher activity in CO_2 methanation reaction. The reaction rate over Ru/TiO_2–Al_2O_3 was 0.59 mol CO_2·(g Ru)1·h-1, 3.1 times higher than that on Ru/Al_2O_3[0.19 mol CO_2·(gRu)-1·h-1]. The effect of TiO_2 content and TiO_2–Al_2O_3calcination temperature on catalytic performance was addressed. The corresponding structures of each catalyst were characterized by means of H_2-TPR, XRD, and TEM. Results indicated that the averaged particle size of the Ru on TiO_2–Al_2O_3support is 2.8 nm, smaller than that on Al_2O_3 support of 4.3 nm. Therefore, we conclude that the improved activity over Ru/TiO_2–Al_2O_3catalyst is originated from the smaller particle size of ruthenium resulting from a strong interaction between Ru and the rutile-TiO_2 support, which hindered the aggregation of Ru nanoparticles.
基金the National Natural Science Foundation of China under grant No. 20476067 Key Project of the National Natural Science Foundation of China, No. 90306014.
文摘Three different Ti-Si oxide structuares, silica supported titania, silica coated titania and intimately mixed silicatitania, containing 10%-40% SiO2, were made by sol-gel process. The variations of microstructure parameters of nanocrystalline （nc） TiO2-anatase in the three kirds of binary oxides, including in-plane spacing d, cell constants （ao, co）, cell volume V, cell axial ratio co/ao and crystal grain size, were comparatively investigated by high resolution transmission electron microscopy （HRTEM） and X-ray diffraction （XRD）. It is found that the microstructure parameters vary remarkably with increasing SiO2 content and annealing temperature. Different structured Ti-Si binary oxides lead to different variation tendencies of microstructure parameters. The more SiO2 the binary oxide contains, the more lattice defects of nc TiO2-anatase appear; diffusion or migration of Si cations could be an important influential factor in the variations of microstructure. The grain size of nc TiO2 in the three kinds of binary oxides not only depends on SiO2 content and annealing temperature but also on the degree of lattice microstrain and distortion of nc TiO2-anatase. Both grain size and phase transformation of nc TiO2-anatase are effectively inhibited with increasing SiO2 content.
文摘Following publication of the original article[1],the authors found that they pasted the same data when drawing XRD for sample NCO-1 and NCO-2 in Fig.2a,however,the XRD of all four samples in the manuscript was tested,and XRD raw data were kept and can be offered.The correct Fig.2 has been provided in this Correction.
基金support from the National Key R&D Program of China(No.2022ZD0119002)the National Natural Science Foundation of China(Grant Nos.62204226,62025402,62090033,92364204,92264202 and 62293522)Major Program of Zhejiang Natural Science Foundation(Grant No.LDT23F04024F04).
文摘Ferroelectric HfO_(2)-based materials and devices show promising potential for applications in information technology but face challenges with inadequate electrostatic control,degraded reliability,and serious variation in effective oxide thickness scaling.We demonstrate a novel interface-type switching strategy to realize ferroelectric characteristics in atomic-scale amorphous binary oxide films,which are formed in oxygen-deficient conditions by atomic layer deposition at low temperatures.This approach can avoid the shortcomings of reliability degradation and gate leakage increment in scaling polycrystalline doped HfO_(2)-based films.Using theoretical modeling and experimental characterization,we show the following.(1)Emerging ferroelectricity exists in ultrathin oxide systems as a result of microscopic ion migration during the switching process.(2)These ferroelectric binary oxide films are governed by an interface-limited switching mechanism,which can be attributed to oxygen vacancy migration and surface defects related to electron(de)trapping.(3)Transistors featuring ultrathin amorphous dielectrics,used for non-volatile memory applications with an operating voltage reduced to±1 V,have also been experimentally demonstrated.These findings suggest that this strategy is a promising approach to realizing next-generation complementary metal-oxide semiconductors with scalable ferroelectric materials.
基金supported by the National Natural Science Foundation of China(21875026,21878031)the Program for Liaoning Excellent Talents in University(LR2014013)+4 种基金the Science and Technology Foundation of Liaoning Province(No.201602052)the Natural Science Foundation of Liaoning Province(No.20170520427)supported by Liaoning Revitalization Talents Program(XLYC1802124)sponsored by the Liaoning BaiQianWan Talents Program,the scientific research fund of the educational department of Liaoning province(J2019013)The Joint Research Fund Liaoning-Shenyang National Laboratory for Materials Science(Project number:2019JH3/30100034,contract number:2019010278-JH3/301).
文摘Although the Ostwald ripening approach is often utilized to manufacture single hollow metal oxide,constructing hollow binary oxide heterostructures as potent photoelectrochemical(PEC)catalysts is still obscure and challenging.Herein,we reveal a general strategy for fabricating hollow binary oxides heterostructures(Co_(3)O_(4)-δ-MnO_(2)and Co_(3)O_(4)–SnO_(2))utilizing Ostwald ripening.Hollow Co_(3)O_(4)-δ-MnO_(2)nano-network with the structure evolution process was systematically explored through experimental and theoretical tools,identifying the origin of hollow binary oxides due to the interfaces acting as landing sites for their growth.In addition,the structural evolution,from hollow Co_(3)O_(4)-δ-MnO_(2)to Co_(3)O_(4)-α-MnO_(2),can be observed when the time of secondary hydrothermal reaches 96 h due to the topotactic layer-to-tunnel transition process.Notably,optimized Co_(3)O_(4)-δ-MnO_(2)-48 exhibits a superior PEC degradation efficiency of 96.42%and excellent durability(20,000 min)under harsh acid conditions,attributed to the massive hollow structures'vast surface area for high intently active species.Furthermore,density functional theory simulations elucidated the Co_(3)O_(4)-δ-MnO_(2)’electron-deficient surface and high d-band center(Co_(3)O_(4)-δ-MnO_(2),-1.06;Co_(3)O_(4)-α-MnO_(2),-1.49),strengthening the interaction between the catalyst's surface and active species and prolonging the lifetime of active species ofO_(2)and 1 O_(2).This work not only demonstrates superior PEC degradation efficiency of hollow Co_(3)O_(4)-δ-MnO_(2)for practical use but also lays the cornerstone for constructing hollow binary oxides heterostructures through Ostwald ripening.
基金supported by the Fund for the Creative Research Groups of China (No. 50921064)the Special Co-construction Project of Beijing Municipal Commission of Education
文摘Significant concerns have been raised over the presence of antibiotics including tetracyclines in aquatic environments.A series of FeMn binary oxide with different Fe：Mn molar ratios was synthesized by a simultaneous oxidation and coprecipitation process for TC removal.Results showed that Fe-Mn binary oxide had higher removal efficiency than that of hydrous iron oxide and hydrous manganese oxide,and that the oxide with a Fe：Mn molar ratio of 5：1 was the best in removal than other molar ratios.The tetracycline removal was highly pH dependent.The removal of tetracycline decreased with the increase of initial concentration,but the absolute removal quantity was more at high concentration.The presence of cations and anions such as Ca2＋,Mg2＋,CO32-and SO42-had no significant effect on the tetracycline removal in our experimental conditions,while SiO32-and PO43-had hindered the adsorption of tetracycline.The mechanism investigation found that tetracycline removal was mainly achieved by the replacement of surface hydroxyl groups by the tetracycline species and formation of surface complexes at the water/oxide interface.This primary study suggests that Fe-Mn binary oxide with a proper Fe：Mn molar ratio will be a very promising material for the removal of tetracycline from aqueous solutions.
基金supported by the National Key Technology R&D Program (No.2018YFD0800202)。
文摘A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO)sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As)and cadmium (Cd) in water.The maximum As(Ⅲ) and Cd(Ⅱ) adsorption capacities of 1%CaSFMBO were 156.25 mg/g and 107.53 mg/g respectively in single-adsorption systems.The adsorption of As and Cd by the Ca-SFMBO sorbent was pH-dependent at values from 1 to 7,with an optimal adsorption pH of 6.In the dual-adsorbate system,the presence of Cd(Ⅱ) at low concentrations enhanced As(Ⅲ) adsorption by 33.3%,while the adsorption of As(Ⅲ) was inhibited with the increase of Cd(Ⅱ) concentration.Moreover,the addition of As(Ⅲ) increased the adsorption capacity for Cd(Ⅱ) up to two-fold.Through analysis by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR),it was inferred that the mechanism for the co-adsorption of Cd(Ⅱ) and As(Ⅲ) included both competitive and synergistic effects,which resulted from the formation of ternary complexes.The results indicate that the Ca-SFMBO material developed here could be used for the simultaneous removal of As(Ⅲ) and Cd(Ⅱ) from contaminated water.
基金Projects(51334008,51304243,51604160)supported by the National Natural Science Foundation of ChinaProject(2016zzts037)supported by the Fundamental Research Funds for the Central Universities,China
文摘Considering the different geochemical enrichment behaviors of W and Mo,Fe?Mn binary oxide(FMBO),ferric hydroxide(Fe(OH)3)and manganese dioxide(MnO2)were studied to separate W from molybdate solution,respectively.The experimental results demonstrated that Fe?Mn binary oxide(FMBO)was the most suitable adsorbent for the separation.Under a wide pH(6.9?11.3)region,more than80%W removal efficiency and less than3%Mo loss could be obtained.In addition,the Fe?Mn binary oxide adsorbent can be regenerated by treating with3mol/L NaOH,and the W adsorption efficiency was retained after five adsorption?desorption?regeneration cycles.All these indicate that the Fe?Mn binary oxides have the potential for the separation of W from molybdate solution.
文摘Binary metal oxide（MnOx-A/TiO2）catalysts were prepared by adding the second metal to manganese oxides supported on titanium dioxide（TiO2）,where,A indicates Fe2O3,WO3,MoO3,and Cr2O3.Their catalytic activity,N2 selectivity,and SO2 poisonous tolerance were investigated.The catalytic performance at low temperatures decreased in the following order：Mn-W/TiO2〉Mn-Fe/TiO2〉Mn-Cr/TiO2〉Mn-Mo/TiO2,whereas the N2 selectivity decreased in the order：Mn-Fe/TiO2〉Mn-W/TiO2〉Mn-Mo/TiO2〉Mn-Cr/TiO2.In the presence of 0.01%SO2 and 6%H2O,the NOx conversions in the presence of Mn-W/TiO2,Mn-Fe/TiO2,or Mn-Mo/TiO2 maintain 98.5%,95.8%and 94.2%, respectively,after 8 h at 120°C at GHSV 12600 h？ 1 .As effective promoters,WO3 and Fe2O3 can increase N2 selectivity and the resistance to SO2 of MnOx/TiO2 significantly.The Fourier transform infrared（FTIR）spectra of NH3 over WO3 show the presence of Lewis acid sites.The results suggest that WO3 is the best promoter of MnOx/TiO2,and Mn-W/TiO2 is one of the most active catalysts for the low temperature selective catalytic reduction of NO with NH3.
基金supported by the National Key Research and Development Program of China(No.2017YFE0127500)National Natural Science Foundation of China(No.U1832155).
文摘Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate,which needs to be addressed by introducing catalysts.Therefore,the design and optimization of catalysts have become the focus of NTP coupling catalysis research.In thiswork,a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system.Among them,Co_(2)Ni_(1)O_(x)achieves 60%carbon dioxide(CO_(2))selectivity(SCO_(2))when the benzene removal efficiency(REbenzene)reaches more than 99%,which is a significant enhancement compared with the CO_(2)selectivity obtained without any catalysts(38%)under the same input power.More intriguingly,this SCO_(2)is also significantly higher than that of single metal oxides,NiO or Co_(3)O_(4),which is only around 40%.Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co_(2)Ni_(1)O_(x)catalyst.The introduction of Co_(2)Ni_(1)O_(x)was found to promote the generation of acrolein significantly,one of the key intermediates found in NTP alone system reported previously,suggest the benzene ring open reaction is promoted.Compared with monometallic oxides NiO and Co_(3)O_(4),Co_(2)Ni_(1)O_(x)also shows higher active oxygen proportion,better oxygenmobility,and stronger low-temperature redox capability.The above factors result in the improved catalytic performance of Co_(2)Ni_(1)O_(x)in the NTP coupling removal of benzene.
基金the Natural Science Foundation of Shaanxi Province(No.2017JM2016)the Fundamental Research Funds for the Central Universities(No.xjj2014005)。
文摘Cerium dioxide has a comparatively lower Ce4+/Ce3+redox pair,which leaves abundant oxygen vacancies on oxide lattice,also making incorporation of foreign ion and subsequent applications feasible and convenient.In this work,a series of cerium-yttrium mixed oxides were prepared by using polyvinylpyrrolidone as major template through sol-gel,which were further employed as catalyst for dehydration of aniline with formic acid into N-phenylformamide.Characterizations reveal that synthetic samples have a variety of morphologies including nanoparticle,microflower,and uniform microrods.The monitoring of particle size,zeta potential,and ultravioletvisible(UV-Vis)of preparative solution indicate that selfassembly of polyvinylpyrrolidone and its subsequent reaction with metal ion determines sample morphology.In catalytic dehydration,all samples show high dehydration efficiencies that are comparable to those from anhydrous Na2SO4 and combination of dicyclohexylcarbodiimide with 4-dimethylaminopyridine and dichloromethane shows better outputs than water.In association with structural analysis,cerium looks more active than yttrium,while yttrium mainly plays as a structure-directing and poreformingagent.Thisstudymaycontributeto micro-/nanofabrication of rare earth composites and their catalytic applications.
基金Item Sponsored by National Natural Science Foundation of China(50764006,50574045)Yunnan Basic Applied Research Foundation of China(2006E0021M)
文摘To confirm sub-regular solution model valid for predicting the activity of component in binary oxide systems, seven systems in the whole concentration and twelve systems presenting saturation concentration have been studied. The total average relative errors of component 1 and 2 are 3.2 % and 4.1% respectively by application of the sub-regular solution model into the systems within the whole concentration. However, the total average relative errors are 16 % and 1088 % in the systems presenting saturation concentration. The results show that sub-regular solu- tion model is not good for predicting the systems presenting saturation concentration, especially for the systems con- taining acidic or neutral oxide. The reason may be that the influence of the two types of oxide on the configuration is greater in binary oxide systems. These oxides can be present in the form of complex anion partly, Si-O, Al-O, Ti-O and so on, for example （SiO4）4-. That is contrary to sub-regular solution model which is supposed that the oxide systems consist of cation and O2-. But compared with regular solution model and quasi-regular solution model, sub- regular solution model is closer to the characteristics of actual solution and the calculated results are superior.
基金supported by the Natural Science Foundation of Shanghai,China (No.18ZR1401000)。
文摘Environmental risks posed by discharge of the emerging contaminant antimony(Sb) into water bodies have raised global concerns recently.The toxicity of Sb has been shown to be species-dependent,with Sb(Ⅲ) demonstrating much greater toxicity than Sb(V).Here,we proposed an electrochemical filtration system to achieve rapid detoxification of Sb(Ⅲ) via a non-radical pathway.The key to this technology was an electroactive carbon nanotube filter functionalized with nanoscale Ti-Ce binary oxide.Under an electric field,in situ generated H_(2) O_(2) could react with the Ti-Ce binary oxide to produce hydroperoxide complexes,which enabled an efficient transformation of Sb(Ⅲ) to the less toxic Sb(V)(τ<2 s) at neutral pH.The impact of important operational parameters was assessed and optimized,and system efficacy could be maintained over a wide pH range and long-term operation.An optimum detoxification efficiency of> 90% was achieved using lake water spiked with Sb(Ⅲ) at 500 μg/L.The results showed that Ti/Ce-hydroperoxo surface complexes were the dominant species responsible for the non-radical oxidation of Sb(Ⅲ) based on extensive experimental evidences and advanced characterizations.This study provides a robust and effective strategy for the detoxification of water containing Sb(Ⅲ) and other similar heavy metal ions by integrating state-of-the-art advanced oxidation processes,electrochemistry and nano-filtration technology.
基金The authors acknowledge Natural Science Foundation of China （No.60174033）；ministry of education and Innovation Foundation of Jilin University
文摘Tube-type CO_2 gas sensors based on NASICON (Na Super Ion Conductor) material were fabricated.The material was synthesized by conventional sol-gel method,and the resulted powders were characterized by XRD.The tube-type CO_2 sensor was prepared with the sensing electrode Li_2CO_3-BaCO_3 binary carbonates in molar ratio 1:1.5.The concentration of CO_2 range from 300μg/g to 3000μg/g,the sensitivity of the sensor was 62.3 mV/decade.The response and recovery time (90%)corresponding to the switching change between 300μg/g and 1000μg/g CO_2 were 20 s and 2 min,respectively.If the sensing electrode was modified with binary oxides,the steady time of the sensor could be greatly reduced from 30 min to 5 min and the stability and humid-resistance of the sensor were improved.
基金supported by The Scientific and Technological Research Council of Turkey(TUBITAK)within the research project 111M210[2011-2013]~~
文摘Binary oxide catalysts with various weight percentage V2O5 loadings were prepared by solid‐state dispersion and the nanocomposites were modified with surfactants. The catalysts were analyzed using X‐ray diffraction, diffuse‐reflectance spectroscopy, Fourier‐transform infrared spectroscopy, scanning electron microscopy, and N2 adsorption‐desorption. The photocatalytic activities of the catalysts were evaluated in the degradation of 2,4‐dichlorophenol under ultraviolet irradiation. The photocatalytic activity of 50 wt%V2O5‐TiO2 （50V2O5‐TiO2） was higher than those of pure V2O5, TiO2, and P25. Interactions between V2O5 and TiO2 affected the photocatalytic efficiencies of the binary oxide catalysts. Cetyltrimethylammonium bromide （CTAB） and hexadecyltrimethylammonium bromide （HTAB） significantly enhanced the efficiency of the 50V2O5‐TiO2 catalyst. The highest per‐centage of 2,4‐dichlorophenol degradation （100%） and highest reaction rate （2.22 mg/（L·min）） were obtained in 30 min with the （50V2O5‐TiO2）‐CTAB catalyst. It is concluded that the addition of a surfactant to the binary oxide significantly enhanced the photocatalytic activity by modifying the optical and electronic properties of V2O5 and TiO2.
文摘The catalyst screening tests for carbon dioxide oxidative coupling of methane (CO2-OCM) have been investigated over ternary and binary metal oxide catalysts. The catalysts are prepared by doping MgO- and CeO2-based solids with oxides from alkali (Li2O), alkaline earth (CaO), and transition metal groups (WO3 or MnO). The presence of the peroxide (O2-2) active sites on the Li2O2, revealed by Raman spectroscopy, may be the key factor in the enhanced performance of some of the Li2O/MgO catalysts. The high reducibility of the CeO2 catalyst, an important factor in the CO2-OCM catalyst activity, may be enhanced by the presence of manganese oxide species. The manganese oxide species increases oxygen mobility and oxygen vacancies in the CeO2 catalyst. Raman and Fourier Transform Infra Red (FT-IR) spectroscopies revealed the presence of lattice vibrations of metal-oxygen bondings and active sites in which the peaks corresponding to the bulk crystalline structures of Li2O, CaO, WO3 and MnO are detected. The performance of 5%MnO/15%CaO/CeO2 catalyst is the most potential among the CeO2-based catalysts, although lower than the 2%Li2O/MgO catalyst. The 2%Li2O/MgO catalyst showed the most promising C2+ hydrocarbons selectivity and yield at 98.0% and 5.7%, respectively.
