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Selective oxidation of aromatic alcohols to aldehydes catalyzed by HKUST-1-derived Cu-based carbon material and TEMPO 认领 引用
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作者 LUO Yang ZHANG Shujing +1 位作者 MA Hong WANG Chenguang 《燃料化学学报（中英文）》 EI CAS CSCD 北大核心 2026年第5期164-173,共10页
In this work,a Cu-based carbon catalyst(H-Cu/C)with an octahedral morphology was synthesized by pyrolyzing the metal-organic framework(MOF)precursor HKUST-1,where Cu(0)nanoparticles were uniformly dispersed in the car... In this work,a Cu-based carbon catalyst(H-Cu/C)with an octahedral morphology was synthesized by pyrolyzing the metal-organic framework(MOF)precursor HKUST-1,where Cu(0)nanoparticles were uniformly dispersed in the carbon matrix,alongside the formation of island-like Cu2O structures as the active sites.Multiple characterization techniques,including XPS,XRD,SEM and HRTEM,reveal the critical role of carbon matrix in stabilizing the metal nanoparticles.In combination with TEMPO and using molecular oxygen as a green oxidant,the H-Cu/C catalyst is highly efficient in the selective oxidation of aromatic alcohols to the corresponding aldehydes under alkali-free conditions.Using benzyl alcohol as a model substrate,an alcohol conversion of 99.2%and a benzaldehyde yield of 94.1%were achieved under mild reaction conditions(100℃,0.5 MPa O2,1 h).The catalytic system displays excellent universality for various mono-and ortho/para-disubstituted aromatic alcohols,affording an alcohol conversion of over 99%and a yield of corresponding aromatic aldehydes of above 95%.In addition,the H-Cu/C catalyst can be regenerated via H2 reduction and reused without significant loss of activity.This work provides a new strategy for designing green and efficient non-noble metal catalytic systems for the oxidation reactions. 展开更多
关键词 metal-organic frameworks(MOFs) copper-based catalysts selective oxidation aromatic alcohols TEMPO
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Unveiling the Selective Oxidation Mechanism of a Low Cr Alloy with Surface Spraying Oxide Nanoparticles of hcp Structure 认领 引用 被引量：1
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作者 Hang Ding Juanjuan Liang +3 位作者 Xin Luo Song Tang Yun Xie Xiao Peng 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2025年第12期2125-2133,共9页
This study systematically explored the oxidation behavior of a Ni-10Cr alloy without and with surface spraying hexagonal closed pack(hcp)-structuredα-Al2O3or α-Fe2O3nanoparticles.Despite the distinct equ... This study systematically explored the oxidation behavior of a Ni-10Cr alloy without and with surface spraying hexagonal closed pack(hcp)-structuredα-Al2O3or α-Fe2O3nanoparticles.Despite the distinct equilibrium dissociation oxygen partial pressure of the two kinds of oxide nanoparticles,they both contributed to the selective oxidation of Ni-10Cr alloy,achieving the transition from internal Cr oxidation to external Cr2O3scale formation.Nano-scaled characterization indicates that a coherent interface was developed between the newly grown Cr2O3grains and the hcp-structured oxide nanoparticles,whereby promoting epitaxial Cr2O3nucleation surrounding the nanoparticles and kinetically accelerating the formation of a continuous Cr2O3scale at the transient oxidation stage.The findings provide new insights into the selective oxidation mechanism of alloys with low Cr contents. 展开更多
关键词 Nanoparticles Selective oxidation High temperature oxidation Low Cr alloy
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MOF encapsulation derived slow-release oxygen species to enhance the activity and selectivity of methane selective oxidation:A transient DRIFTs Study 认领 引用
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作者 Ke-Xin Li Hao Yuan +1 位作者 Ralph T.Yang Zhun Hu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2025年第11期202-214,共13页
The methane selective oxidation was a"holy grail"reaction.However,peroxidation and low selectivity limited the application.Herein,we combined three Au contents with TiO2in both encapsulation(xAu@TiO2)a... The methane selective oxidation was a"holy grail"reaction.However,peroxidation and low selectivity limited the application.Herein,we combined three Au contents with TiO2in both encapsulation(xAu@TiO2)and surface-loaded(xAu/TiO2)ways by MOF derivation strategy,reported a catalyst 0.5Au@TiO2exhibited a CH3OH yield of 32.5μmol·g-1·h-1and a CH3OH selectivity of 80.6%under catalytic conditions of only CH4,O2,and H2O.Mechanically speaking,the catalytic activity was controlled by both electron-hole separation efficiency and core-shell structure.The interfacial contact between Au nanoparticles and TiO2in xAu@TiO2and xAu/TiO2induced the formation of oxygen vacancies,with 0.5 Au content showing the highest oxygen vacancy concentration.At the same Au content,xAu@TiO2generated more oxygen vacancies than xAu/TiO2.The oxygen vacancy acted as an effective electron cold trap,which enhanced the photogenerated carrier separation efficiency and thereby improved the catalytic activity.In-situ DRIFTs revealed that the isolated OH(non-hydrogen bond adsorption)were key species for the methane selective oxidation,playing a role in the activation of CH4to*CH3.However,an overabundance of isolated OH led to severe overoxidation.Fortunately,the core-shell structure over xAu@TiO2provided a slow-release environment for isolated OH through the intermediate state of*OH(hydrogen bond adsorption)to balance the formation rate and consumption rate of isolated OH,doubling the methanol yield and increasing the>29%selectivity.These results showed a new strategy for the control of the overoxidation rate via a strategy of MOF encapsulation followed by pyrolytic derivation for methane selective oxidation. 展开更多
关键词 Methane selective oxidation Metal-organic framework derived Reactive oxygen species modulation Hydrogen bonded adsoprotion hydroxyl groups
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Enhanced selective oxidation of dimethyl ether to formaldehyde by MoO3-Fe2(MoO4)3 interaction over iron-molybdate catalysts 认领 引用
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作者 Yafei Liang Yuji Qi +6 位作者 Mingli Bi Zhen Shi Junju Mu Shushuang Li Jian Zhang Yehong Wang Feng Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2025年第7期832-841,共10页
The efficient catalytic conversion of fossil-based low-carbon small molecules to oxygen-containing chemicals is an attractive research topic in the fields of energy and chemical engineering.The selective oxidation of ... The efficient catalytic conversion of fossil-based low-carbon small molecules to oxygen-containing chemicals is an attractive research topic in the fields of energy and chemical engineering.The selective oxidation of dimethyl ether(DME),which is derived from fossil resources,represents a promising approach to producing high-concentration formaldehyde with low energy consumption.However,there is still a lack of catalysts achieving satisfactory conversion of DME with high selectivity for formaldehyde under mild conditions.In this work,an efficient iron-molybdate(FeMo)catalyst was developed for the selective oxidation of DME to formaldehyde.The DME conversion of 84% was achieved with a superior formaldehyde selectivity(77%)at 300℃,a performance that is superior to all previously reported results.In an approximately 550 h continuous reaction,the catalyst maintained a conversion of 64% and a formaldehyde selectivity of 79%.Combined X-ray diffraction(XRD),Transmission electron microscope(TEM),Ultraviolet-visible spectroscopy(UV-Vis),Hydrogen temperature-programmed reduction(H2-TPR),Fourier transform infrared(FT-IR)analyses,along with density functional theory(DFT)calculations,demonstrated that the excellent FeMo catalyst was composed of active Fe2(MoO4)3and MoO3phases,and there was an interaction between them,which contributed to the efficient DME dissociation and smooth hydrogen spillover,leading to a superior DME conversion.With the support of DME/O2pulse experiments,in-situ Raman,in-situ Dimethyl ether infrared spectroscopy(DME-IR)and DFT calculation results,a Mars-van Krevelen(MvK)reaction mechanism was proposed:DME was dissociated on the interface between Fe2(MoO4)3and MoO3phases to form active methoxy species firstly,and it dehydrogenated to give hydrogen species;the generated hydrogen species smoothly spilled over from Fe2(MoO4)3to MoO3enhanced by the interaction between Fe2(MoO4)3and MoO3;then the hydrogen species was consumed by MoO3,leading to a reduction of MoO3,and finally,the reduced MoO3was re-oxidized by O2,returning to the initial state.These findings offer valuable insights not only for the development of efficient FeMo catalysts but also for elucidating the reaction mechanism involved in the oxidation of DME to formaldehyde,contributing to the optimized utilization of DME derived from fossil resources. 展开更多
关键词 Dimethyl ether Selective oxidation FeMo catalyst Formaldehyde Interaction
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Unveiling the catalytic active sites of iron-vanadium catalysts for the selective oxidation of methanol to formaldehyde 认领 引用
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作者 Yujie Zhan Chengqin Zhong +8 位作者 Mingli Bi Yafei Liang Yuji Qi Jiaqi Chen Jiaxu Liu Xindang Zhang Shuai Zhang Yehong Wang Feng Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2025年第5期334-343,共10页
Iron-Vanadium(FeV)catalyst showed a unique catalytic activity for the selective oxidation of methanol to formaldehyde;however,due to its complex compositions,the identification of catalytic active sites still remains ... Iron-Vanadium(FeV)catalyst showed a unique catalytic activity for the selective oxidation of methanol to formaldehyde;however,due to its complex compositions,the identification of catalytic active sites still remains challenging,inhibiting the rational design of excellent FeV-based catalysts.Here,in this work,a series of FeV catalysts with various compositions,including FeVO4,isolated VOx,low-polymerized VnOx,and crystalline V2O5 were prepared by controlling the preparation conditions,and were applied to methanol oxidation to formaldehyde reaction.A FeV1.1 catalyst,which consisted of FeVO4 and low-polymerized VnOx species showed an excellent catalytic performance with a methanol conversion of 92.3%and a formaldehyde selectivity of 90.6%,which was comparable to that of conventional iron-molybdate catalyst.The results of CH3OH-IR,O2 pulse and control experiments revealed a crucial synergistic effect between FeVO4 and low-polymerized VnOx.It enhanced the oxygen supply capacity and suitable binding and adsorption strengths for formaldehyde intermediates,contributing to the high catalytic activity and formaldehyde selectivity.This study not only advances the understanding of FeV structure but also offers valuable guidelines for selective methanol oxidation to formaldehyde. 展开更多
关键词 Iron-vanadium Selective oxidation Methanol Formaldehyde Synergistic effect
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Development of multifunctional Co3O4-modified ZnIn2S4 photocatalyst for the selective oxidation of biomass-derived 5-hydroxymethylfurfural 认领 引用
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作者 Shan Jiang Zhenpan Chen +3 位作者 Shaofeng Xiong Hongxin Zhao Xishun Xiao Zhigang Shen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2025年第10期830-838,共9页
The photocatalytic selective oxidation of biomass-derived 5-hydroxymethylfurfural(HMF)offers a sustainable alternative to thermal catalysis.However,the efficiency of this process is significantly limited by inadequate... The photocatalytic selective oxidation of biomass-derived 5-hydroxymethylfurfural(HMF)offers a sustainable alternative to thermal catalysis.However,the efficiency of this process is significantly limited by inadequate light absorption efficiency and the rapid recombination of photogenerated charge carriers in conventional photocatalysts.Herein,we developed a Co3O4/ZnIn2S4(Co3O4/ZIS)photocatalyst,in which Co3O4functions as a multifunctional cocatalyst.This photocatalyst significantly enhances the chemisorption and activation of HMF molecules through interfacial oxygen-hydroxyl interactions.Additionally,the incorporation of narrow-band gap Co3O4broadens the optical absorption range of the composite photocatalyst.Besides,integrating Co3O4with ZnIn2S4leads to a 5.9-fold increase in charge separation efficiency compared to pristine ZnIn2S4.The optimized Co3O4/ZIS-3 photocatalyst(3 wt% Co3O4loading)exhibits exceptional selectivity and yield for 2,5-diformylfuran(DFF)under visible light irradiation,achieving 70.4%DFF selectivity with a 5.4-fold enhancement compared to pristine ZnIn2S4.Scavenger experiments and electron spin resonance(ESR)spectroscopy indicate that superoxide radicals(O2-)and h+are the main active species driving the photocatalytic oxidation of HMF.Molecular simulations reveal that the activation of HMF and the transformation of the intermediate*MF to*DFF are more favorable over the Co3O4/ZIS composite due to lower activation barriers compared to those over ZnIn2S4.Through this work,we aim to design highly efficient and affordable photocatalysts for biomass valorization and contribute valuable insights into the mechanisms of photocatalytic oxidation of HMF. 展开更多
关键词 Photocatalysis Selective oxidation Cocatalyst 5-Hydroxymethylfurfural
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Morphology evolution of acetic acid-modulated MIL-53(Fe)for efficient selective oxidation of H2S 认领 引用 被引量：8
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作者 Xiaoxiao Zheng Sihui Qi +3 位作者 Yanning Cao Lijuan Shen Chaktong Au Lilong Jiang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第2期279-287,共9页
MIL-53(Fe)was synthesized using a“modulator approach”that utilizes acetic acid(HAc)as an additive to control the size and morphology of the resulting crystals.We demonstrate that after activation under vaccum at 100... MIL-53(Fe)was synthesized using a“modulator approach”that utilizes acetic acid(HAc)as an additive to control the size and morphology of the resulting crystals.We demonstrate that after activation under vaccum at 100℃,the MIL-53(Fe)functions well for H2S selective oxidation.The introduction of acetic acid in the presence of benzene-1,4-dicarboxylic acid(H2BDC)would result in a series of MIL-53(Fe)nanocrystals(denoted as MIL-53(Fe)-xH,x stands for the volume of added HAc with morphology evoluting from irregular particles to short hexagonal columns.The vacuum treatment facilitates the removal of acetate groups,thus generating Fe3+Lewis acid sites.Consequently,the resulted MIL-53(Fe)-xH exhibits good catalytic activity(98%H2S conversion and 92%sulfur selectivity)at moderate reaction temperatures(100–190℃).The MIL-53(Fe)-5H is superior to the traditional iron-based catalysts,showing stable performance in a test period of 55 h. 展开更多
关键词 Fe-metal-organic frameworks Hydrogen sulfide Selective oxidation Controllable synthesis Acetic acid Modulation
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Biomass-based N doped carbon as metal-free catalyst for selective oxidation of D-xylose into D-xylonic acid 认领 引用 被引量：6
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作者 Zengyong Li Yiming Huang +5 位作者 Xiao Chi Di Li Linxin Zhong Xuehui Li Chuanfu Liu Xinwen Peng 《Green Energy & Environment》 SCIE EI CAS CSCD 2022年第6期1310-1317,共8页
Rational design and facile preparation of low-cost and efficient catalysts for the selective converting of biomass-derived monosaccharides into high value-added chemicals is highly demanded,yet challenging.Herein,we f... Rational design and facile preparation of low-cost and efficient catalysts for the selective converting of biomass-derived monosaccharides into high value-added chemicals is highly demanded,yet challenging.Herein,we first demonstrate a N doped defect-rich carbon(NC-800-5)as metal-free catalyst for the selective oxidation of D-xylose into D-xylonic acid in alkaline aqueous solution at 100℃ for 30 min,with 57.4%yield.The doped graphitic N is found to be the active site and hydroxyl ion participating in the oxidation of D-xylose.Hydroxyl ion and D-xylose first adsorb on NC-800-5 surface,and the aldehyde group of D-xylose is catalyzed to form germinal diols ion.Then,C–H bond break to yield carboxylic group.Furthermore,NC-800-5 catalyst shows high stability in recycled test. 展开更多
关键词 Biomass carbon Metal-free catalysts D-xylose Sugar acid Selective oxidation
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Preparation and characterization of Ce1-xFe_xO_2 complex oxides and its catalytic activity for methane selective oxidation 认领 引用 被引量：10
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作者 李孔斋 王华 +1 位作者 魏永刚 刘明春 《Journal of Rare Earths》 SCIE EI CAS 2008年第2期245-249,共5页
A series of Ce1-xFexO2 （x=0, 0.2, 0.4, 0.6, 0.8, 1） complex oxide catalysts were prepared using the coprecipitation method. The catalysts were characterized by means of XRD and H2-TPR. The reactions between methane ... A series of Ce1-xFexO2 （x=0, 0.2, 0.4, 0.6, 0.8, 1） complex oxide catalysts were prepared using the coprecipitation method. The catalysts were characterized by means of XRD and H2-TPR. The reactions between methane and lattice oxygen from the complex oxides were investigated. The characteristic results revealed that the combination of Ce and Fe oxide in the catalysts could lower the temperature necessary to reduce the cerium oxide. The catalytic activity for selective CH4 oxidation was strongly influenced by dropped Fe species. Adding the appropriate amount of Fe2O3 to CeO2 could promote the action between CH4 and CeO2. Dispersed Fe2O3 first returned to the original state and would then virtually form the Fe species on the catalyst, which could be considered as the active site for selective CH4 oxidation. The appearance of carbon formation was significant and the oxidation of carbon appeared to be the rate-determining step; the amounts of surface reducible oxygen species in CeO2 were also relevant to the activity. Among all the catalysts, Ce0.6Fe0.402 exhibited the best activity, which converted 94.52% of CH4 at 900 ℃. 展开更多
关键词 Ce1-xFexO2 complex oxides H2-TPR lattice oxygen methane selective oxidation rare earths
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Selective Oxidation of Isobutylene over Cs-promoted Mo-Bi-Co-Fe-Ce-O Catalyst 认领 引用 被引量：6
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作者 王蕾 李增喜 +2 位作者 张锁江 张香平 赵威 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2005年第5期705-708,共4页
Cs-promoted Mo-Bi-Co-Fe-Ce-O catalyst for the selective oxidation of isobutylene to methacrolein had been studied in a fixed bed micro-reactor. The selectivity to methacrolein was significantly improved by the additio... Cs-promoted Mo-Bi-Co-Fe-Ce-O catalyst for the selective oxidation of isobutylene to methacrolein had been studied in a fixed bed micro-reactor. The selectivity to methacrolein was significantly improved by the addition of Cs, which could probably enhance the dehydrogenation ability and weaken the oxygenation ability of the catalyst based on temperature programmed reduction （TPR） analysis investigation. The kinetic studies indicated that the oxidation of isobutylene to methacrolein followed the first-order kinetic behavior. 展开更多
关键词 isobutylene selective oxidation complex catalyst kinetics
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Selective Oxidation of Light Hydrocarbons Using Lattice Oxygen Instead of Molecular Oxygen 认领 引用 被引量：6
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作者 沈师孔 李然家 +1 位作者 周吉萍 余长春 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2003年第6期649-655,共7页
In this paper, selective oxidation of n-butane to maleic anhydride (MA) and partial oxidation of methane to synthesis gas with lattice oxygen instead of molecular oxygen are investigated. For the oxidation of butane t... In this paper, selective oxidation of n-butane to maleic anhydride (MA) and partial oxidation of methane to synthesis gas with lattice oxygen instead of molecular oxygen are investigated. For the oxidation of butane to MA in the absence of molecular oxygen, the Ce-Fe promoted VPO catalyst has more available lattice oxygen and provides higher conversion and selectivity than that of the unpromoted one. It is supposed that the introduction of Ce-Fe complex oxides improves redox performance of VPO catalyst and increases the activity of lattice oxygen. For partial oxidation of methane to synthesis gas over LaFeO3 and La0.8Sr0.2FeO3 oxides, the reaction with flow switched between 11% O2-Ar and 11% CH4-He at 900℃ was carried out. The results show that methane can be oxidized to CO and H2 with selectivity over 93% by the lattice oxygen of the catalyst in an appropriate reaction condition, while the lost lattice oxygen can be supplemented by air re-oxidation. It is viable for the lattice oxygen of the LaFeO3 and La0.8Sr0.2FeO3 catalyst instead of molecular oxygen to react with methane to synthesis gas in the redox mode. 展开更多
关键词 selective oxidation lattice oxygen n-butane maleic anhydride Ce-Fe promoted VPO catalysts methane synthesis gas La1-xSrxFeO3 perovskite catalysts
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Selective Oxidation of Ethane to Aldehydes over Potassium-Promoted SBA-15-Supported Molybdenum Oxide Catalysts 认领 引用 被引量：4
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作者 LI Jian-Mei LIU Jian +5 位作者 REN Li-Wei LIU Qing-Long ZHAO Zhen WEI Yue-Chang DUAN Ai-Jun JIANG Gui-Yuan 《物理化学学报》 SCIE CAS CSCD 北大核心 2014年第9期1736-1744,共9页
Potassium-modified SBA-15-supported molybdenum oxide catalysts were prepared using a two-step impregnation method.The physical and chemical properties of the catalysts were characterized using N2-adsorption-desorpt... Potassium-modified SBA-15-supported molybdenum oxide catalysts were prepared using a two-step impregnation method.The physical and chemical properties of the catalysts were characterized using N2-adsorption-desorption,X-ray diffraction(XRD),transmission electron microscope(TEM),UV-visible(UV-Vis)spectroscopy,Raman spectroscopy,NH3temperature-programmed desorption(NH3-TPD),CO2temperature-programmed desorption(CO2-TPD),and H2temperature-programmed reduction(H2-TPR).The results showed that potassium addition resulted in the formation of new potassium molybdates,and the states of molybdenum species varied with changes in the K/Mo molar ratio.The addition of potassium to Mo0.75SBA-15 effectively improved the activity of catalysts and the selectivity to the total aldehydes(formaldehyde,acetaldehyde,and acrolein),especially for acetaldehyde in the selective oxidation of ethane.The turn-over frequency(TOF)and product selectivity depended strongly on the potassium content.The maximum selectivity and yield of aldehydes were obtained by varying the K/Mo molar ratio.At 575℃,the maximum yield of aldehydes reached 8.5%(molar fraction)over K0.25-Mo0.75/SBA-15 catalyst.The formation of new potassium-molybdates promoted the activities and selectivities of the catalysts. 展开更多
关键词 Selective oxidation of ethane K-modified catalyst Molybdenum oxide Aldehyde SBA-15 mesoporous material
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Thiazolo[5,4-d]thiazole-based covalent organic framework microspheres for blue light photocatalytic selective oxidation of amines with O2 认领 引用 被引量：4
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作者 Fulin Zhang Xia Li +2 位作者 Xiaoyun Dong Huimin Hao Xianjun Lang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第9期2395-2404,共10页
Covalent organic frameworks(COFs)with photoactive units have attracted significant interest in visible light photocatalysis and can present a metal‐free scenario for activating O2.As a typical photoactive unit,thi... Covalent organic frameworks(COFs)with photoactive units have attracted significant interest in visible light photocatalysis and can present a metal‐free scenario for activating O2.As a typical photoactive unit,thiazolo[5,4‐d]thiazole(TzTz)has rarely been added to COFs.However,circumventing the low reversibility of TzTz,it could be embedded into the building blocks beforehand,along with other bonds likeβ‐ketoenamine in forming COFs.TzTz was embedded into 1,1′‐biphenyl‐4,4′‐diamine(BD)using this approach to produce 4,4′‐(TzTz‐2,5‐diyl)dianiline(DTz).Under organobase‐modulated solvothermal conditions,combining 1,3,5‐triformylphloroglucinol(Tp)with BD and DTz resulted in the production ofβ‐ketoenamine‐linked TpBD‐COF and TpDTz‐COF.Both TpDTz‐COF and TpBD‐COF are microspheres.TpDTz‐COF possessed more adequate separation and charge migration than TpBD‐COF.This resulted in superior performance for the blue light photocatalytic selective oxidation of benzylamine with O2.Furthermore,with O2 as the main oxidant,a wealth of benzylamines could be converted into imines over TpDTz‐COF.Mechanistic investigations substantiate that oxidation of benzylamines obeys an electron transfer pathway,in which superoxide anion(O2•–)is the crucial reactive oxygen species.This study highlights the superiority of TzTz‐embedded COFs in developing effective photocatalytic systems for organic transformations. 展开更多
关键词 Covalent organic framework Thiazolo[5 4-d]thiazole Visible light Photocatalysis Selective oxidation
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Solvent-free selective oxidation of cyclohexane with molecular oxygen over manganese oxides:Effect of the calcination temperature 认领 引用 被引量：4
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作者 吴明周 詹望成 +5 位作者 郭耘 王筠松 郭杨龙 龚学庆 王丽 卢冠忠 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第1期184-192,共9页
The effects of calcination temperature on the physicochemical properties of manganese oxide catalysts prepared by a precipitation method were assessed by X-ray diffraction,N2 adsorption-desorption,X-ray photoelectron ... The effects of calcination temperature on the physicochemical properties of manganese oxide catalysts prepared by a precipitation method were assessed by X-ray diffraction,N2 adsorption-desorption,X-ray photoelectron spectroscopy,H2 temperature-programmed reduction,O2 temperature-programmed desorption,and thermogravimetry-differential analysis.The catalytic performance of each of these materials during the selective oxidation of cyclohexane with oxygen in a solvent-free system was subsequently examined.It was found that the MnOx-500 catalyst,calcined at 500 °C,consisted of a Mn2O3 phase in addition to Mn5O8 and Mn3O4 phases and possessed a low surface area.Unlike MnOx-500,the MnOx-400 catalyst prepared at 400 °C was composed solely of Mn3O4 and Mn5O8 and had a higher surface area.The pronounced catalytic activity of this latter material for the oxidation of cyclohexene was determined to result from numerous factors,including a higher concentration of surface adsorbed oxygen,greater quantities of the surface Mn4＋ ions that promote oxygen mobility and the extent of O2 adsorption and reducibility on the catalyst.The effects of various reaction conditions on the activity of the MnOx-400 during the oxidation of cyclohexane were also evaluated,such as the reaction temperature,reaction time,and initial oxygen pressure.Following a 4 h reaction at an initial O2 pressure of 0.5 MPa and 140 °C,an 8.0% cyclohexane conversion and 5.0% yield of cyclohexanol and cyclohexanone were achieved over the MnOx-400 catalyst.In contrast,employing MnOx-500 resulted in a 6.1% conversion of cyclohexane and 75% selectivity for cyclohexanol and cyclohexanone.After being recycled through 10 replicate uses,the catalytic activity of the MnOx-400 catalyst was unchanged,demonstrating its good stability. 展开更多
关键词 Manganese oxide catalyst Selective oxidation of cyclohexane Oxygen Calcination temperature Solvent-free reaction
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Chemical interaction of Ce-Fe mixed oxides for methane selective oxidation 认领 引用 被引量：4
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作者 祝星 杜云鹏 +3 位作者 王华 魏永刚 李孔斋 孙令玥 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第9期824-830,共7页
Chemical interaction of Ce-Fe mixed oxides was investigated in methane selective oxidation via methane temperature programmed reduction and methane isothermal reaction tests over Ce-Fe oxygen carriers. In methane temp... Chemical interaction of Ce-Fe mixed oxides was investigated in methane selective oxidation via methane temperature programmed reduction and methane isothermal reaction tests over Ce-Fe oxygen carriers. In methane temperature programmed reduction test, Ce-Fe oxide behaved complete oxidation at the lower temperature and selective oxidation at higher temperatures. Ce-Fe mixed oxides with the Fe content in the range of 0.1~）.5 was able to produce syngas with high selectivity in high-temperature range （800-900 ~C）, and a higher Fe amount over 0.5 seemed to depress the CO formation. In isothermal reaction, complete oxidation oc- curred at beginning following with selective oxidation later. Ce~_xFexO2~ oxygen carriers （x5_0.5） were proved to be suitable for the selective oxidation of methane. Ce-Fe mixed oxides had the well-pleasing reducibility with high oxygen releasing rate and CO selec- tivity due to the interaction between Ce and Fe species. Strong chemical interaction of Ce-Fe mixed oxides originated from both Fe＊ activated CeO2 and Ce3＋ activated iron oxides （FeOm）, and those chemical interaction greatly enhanced the oxygen mobility and selectivity. 展开更多
关键词 chemical interaction Ce-Fe mixed oxides methane selective oxidation rare earths
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Small-sized cuprous oxide species on silica boost acrolein formation via selective oxidation of propylene 认领 引用 被引量：3
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作者 Ling-Ling Guo Jing Yu +6 位作者 Wei-Wei Wang Jia-Xu Liu Hong-Chen Guo Chao Ma Chun-Jiang Jia Jun-Xiang Chen Rui Si 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第2期320-333,共14页
Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for the... Oxide-supported copper-containing materials have attracted considerable research attention as promising candidates for acrolein formation.Nevertheless,the elucidation of the structure-performance relationships for these systems remains a scientific challenge.In this work,copper oxide clusters deposited on a high-surface-area silica support were synthesized via a deposition-precipitation approach and exhibited remarkable catalytic reactivity(up to 25.5%conversion and 66.8%selectivity)in the propylene-selective oxidation of acrolein at 300℃.Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy combined with X-ray absorption fine structure measurements of the catalyst before and after the reaction confirmed the transformation of the small-sized copper oxide(CuO)clusters into cuprous oxide(Cu2O)clusters.With the aid of in situ X-ray diffraction and in situ dual beam Fourier transform infrared spectroscopy(DB-FTIR),the allyl intermediate(CH2=CHCH2*)was clearly observed,along with the as-formed Cu2O species.The intermediate can react with oxygen atoms from neighboring Cu2O species to form acrolein during the catalytic process,and the small-sized Cu2O clusters play a crucial role in the generation of acrolein via the selective oxidation of propylene. 展开更多
关键词 Propylene selective oxidation Cuprous oxide cluster Acrolein formation Active species In situ characterization
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Selective oxidation of methane to formaldehyde by oxygen over silica-supported iron catalysts 认领 引用 被引量：5
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作者 Jieli He Yang Li +2 位作者 Dongli An Qinghong Zhang Ye Wang 《Journal of Natural Gas Chemistry》 2009年第3期288-294,共7页
FeOx-SiO2 catalysts prepared by a sol-gel method were studied for the selective oxidation of methane by oxygen.A single-pass formaldehyde yield of 2.0%was obtained over the FeOx-SiO2 with an iron content of 0.5 wt%at ... FeOx-SiO2 catalysts prepared by a sol-gel method were studied for the selective oxidation of methane by oxygen.A single-pass formaldehyde yield of 2.0%was obtained over the FeOx-SiO2 with an iron content of 0.5 wt%at 898 K.This 0.5 wt%FeOx-SiO2 catalyst demonstrated significantly higher catalytic performances than the 0.5 wt%FeOx/SiO2 prepared by an impregnation method.The correlation between the catalytic performances and the characterizations with UV-Vis and H2-TPR suggested that the higher dispersion of iron species in the catalyst prepared by the sol-gel method was responsible for its higher catalytic activity for formaldehyde formation.The modification of the FeOx-SiO2 by phosphorus enhanced the formaldehyde selectivity,and a single-pass formaldehyde yield of 2.4%could be attained over a P-FeOx-SiO2 catalyst(P/Fe=0.5)at 898 K.Raman spectroscopic measurements indicated the formation of FePO4 nanoclusters in this catalyst,which were more selective toward formaldehyde formation. 展开更多
关键词 selective oxidation methane formaldehyde iron catalyst sol-gel method
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Selective oxidation of ethane to aldehydes over SBA-15 supported molybdenum catalyst 认领 引用 被引量：2
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作者 Jianmei Li Jian Liu +7 位作者 Liwei Ren Qinglong Liu Zhen Zhao Yongsheng Chen Pengyu Zhu Yuechang Wei Aijun Duan Guiyuan Jiang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第5期609-616,共8页
SBA-15 supported Mo catalysts （Moy/SBA-15） were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsor... SBA-15 supported Mo catalysts （Moy/SBA-15） were prepared by an ultrasonic assisted incipient-wetness impregnation method. The physical and chemical properties of the catalysts were characterized by means of N2-adsorption-desorption, XRD, TEM, UV-Vis, Raman, XANES and H2-TPR. The results showed that a trace amount of MoO3 was produced on high Mo content samples. Tum-over frequency （TOF） and product selectivity are dependent on the molybdenum content. Both Mo0.75/SBA-15 and Mo1.75/SBA-15 catalysts give the higher catalytic activity and the selectivity to the total aldehydes for the selective oxidation of C2H6. At the reaction temperature of 625℃, the maximum yield of aldehydes reached 4.2% over Mo0.75/SBA-15 catalyst. The improvement of the activity and selectivity was related with the state of MoOx species. 展开更多
关键词 selective oxidation of ethane supported oxides catalysts Mo aldehydes SBA-15
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Solvothermal Synthesis of ZnIn2S4 by Alcohol Solvents and Visible Light Photocatalytic Activity on Selective Oxidation and Dye Degradation 认领 引用 被引量：2
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作者 何运慧 陈志鑫 +2 位作者 许静静 吴艳 肖光参 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第5期753-762,共10页
A series of hexagonal ZnIn2S4 samples with different morphologies have been successfully prepared via a facile solvothermal approach using different alcohol solvents with the optimum synthesis time and temperature. X-... A series of hexagonal ZnIn2S4 samples with different morphologies have been successfully prepared via a facile solvothermal approach using different alcohol solvents with the optimum synthesis time and temperature. X-ray diffraction, field emission scanning electron microscopy, UV-vis diffuse reflection spectroscopy and photoelectrochemical measurements are employed to determine the properties of the samples. It is found that the solvent has a significant influence on the morphology, optical properties and electronic nature of the samples. The photocatalytic activities of the samples have been evaluated by selective oxidation of benzyl alcohol to benzaldehyde to benzaldehyde and the degradation of methyl orange（MO） under visible light irradiation. The results reveal that the photocatalytic activities of ZnIn2S4 are closely related to the reaction solvent. The ethanol-mediated ZnIn2S4 exhibits the best photocatalytic performance toward selective oxidation of benzyl alcohol to benzaldehyde and the degradation of dye MO compared to the samples prepared in other solvents, which can be attributed to the integrative effect of the enhanced light absorption intensity and the prolonged lifetime of photogenerated carriers. In addition, a possible mechanism is proposed and discussed. It is expected that our current research could promote further interest on the synthesizing efficient ternary chalcogenides semiconducting materials for environment remediation and organic transformation. 展开更多
关键词 photocatalyst solvothermal selective oxidation methyl orange visible light
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Mass Spectrometric Studies of Selective Oxidation of n-Butane over a Vanadium Phosphorus Oxide Catalyst 认领 引用 被引量：2
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作者 陈标华 黄晓峰 +2 位作者 李成岳 梁日忠 赵邦蓉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2002年第2期177-182,共6页
The selective oxidation of n-butane to maleic anhydride (MA) on a vanadium-phosphorus oxide (VPO) catalyst was studied using on-line gas-chromatography combined with mass spectrometry(GC-MS) and transient response tec... The selective oxidation of n-butane to maleic anhydride (MA) on a vanadium-phosphorus oxide (VPO) catalyst was studied using on-line gas-chromatography combined with mass spectrometry(GC-MS) and transient response technique. The reaction intermediates, buterie and furan, were found in the reaction effluent under near industrial feed condition (3% butane+15%O2), while dihydrofuran was detected at high butane concentration (12% butane, 5%O2). Some intermediates of MA decomposition were also identified. Detection of these intermediates shows that the vanadium phosphorus oxides are able to dehydrogenate butane to butene, and butene further to form MA. Based on these observations, a modified scheme of reaction network is proposed. The transient experiments show that butane in the gas phase may directly react with oxygen both on the surface and from the metal oxide lattice, without a proceeding adsorption step. Gas phase oxygen can be adsorbed and transformed to surface lattice oxygen but it can not participate in selective oxidation. Adsorbed oxygen leads to deep oxidation, while lattice oxygen leads to selective oxidation. 展开更多
关键词 n-butane selective oxidation vanadium phosphorus oxide catalyst mass spectrometer reaction in- termediates transient response
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