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Catalytic behavior of Mo-Bi-Fe-Co-K-M-O(M=Ce,Gd,CeGd)catalysts for selective oxidation of isobutene

Journal of Rare Earths 2024年第1期42卷 84-93,I0003页

作者： Qinghui Li Huahua Zhao Jian Yang Jun Zhao Liang Yan Huanling Song Lingjun Chou State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Beijing100049China

The further improvement of methacrolein(MAL)selectivity from isobutene(IB)oxidation is crucial and challenging.In this study,based on the typical Mo-Bi-Fe-Co-K-O mixed metal oxide,the rare earth element Gd-doped,Ce-doped and CeGd co-doped catalysts were prepared by co-precipitation strategy to increase the selectivity of MAL from 47.9%to 49.8%,64.2% and 68.6%,respectively.In order to elucidate in-depth the promoting effect of Ce and/or Gd,various characterizations were utilized including X-ray diffraction patterns(XRD),Raman,X-ray fluorescence spectrometry(XRF),X-ray photoelectron spectroscopy(XPS),O_(2)-temperature programmed desorption(O_(2)-TPD),H2-temperature programmed reduction(H2-TPR),CO_(2)-temperature programmed desorption(CO_(2)-TPD),IB-temperature programmed desorption(i-C4-TPD)and in-situ IB-Fourier transform infrared spectroscopy(IB-FTIR).Both Ce and Gd finely regulate the bulk and surface structure of the catalyst,thus altering the redox ability,oxygen mobility and storage ability and basicity.Compared with Ce,Gd addition slightly regulates the variation of Co^(2+)/Co^(3+)redox couples,greatly enhances the interaction among the components on the catalyst,thus only increases the content of surface oxygen species and has little effect on their mobility.While Cecontaining catalyst performs stronger oxygen storage and migration ability,thus leading to the overproduction of surface Odefectspecies,which are proposed to be the active sites for the production of MAL and COx.The CeGd co-doped catalyst possesses the proper content of surface Odefectspecies,thus exhibits much higher MAL selectivity.Moreover,the promoting mechanism of Ce and/or Gd over IB oxidation is proposed.Therefore,this work is helpful for understanding the influence of rare earth elements on the structure of mixed metal oxides and the olefin selective oxidation reaction.

关键词： Mixed metal oxide catalyst Rare earth element Isobutene Selective oxidation methacrolein

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Sources of methacrolein and methyl vinyl ketone and their contributions to methylglyoxal and formaldehyde at a receptor site in Pearl River Delta

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Journal of Environmental Sciences 2019年第5期31卷 1-10页

作者： Zhenhao Ling Zhuoran He Zhe Wang Min Shao Xuemei Wang School of Atmospheric Sciences Sun Yat-sen University Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Department of Civil and Environmental Engineering Hong Kong Polytechnic University Institute for Environmental and Climate Research Jinan University

methacrolein(MACR) and methyl vinyl ketone(MVK) are two major intermediate products from the photochemical oxidation of isoprene, the most important biogenic volatile organic compound. In addition, MACR and MVK have primary emissions. Investigating the sources and evolution of MACR and MVK could provide helpful information for the oxidative capacity of the atmosphere. In this study, hourly measurements of isoprene, MACR, and MVK were conducted at a receptor site in the Pearl River Delta region(PRD), i.e., the Heshan site(HS), from 22 October to 20 November, 2014. The average mixing ratios of isoprene,MACR and MVK were 151 ± 17, 91 ± 6 and 79 ± 6 pptv, respectively. The daily variations and the ratios of MVK/MACR during daytime and nighttime suggested that other sources besides isoprene photooxidation influenced the MACR and MVK abundances at the HS.Positive matrix factorization was utilized to resolve the sources of MACR and MVK. Five sources were identified and quantified, including biogenic emissions, biomass burning,secondary formation, diesel, and gasoline vehicular emissions. Among them, secondary formation made the greatest contribution to observed MACR and MVK with average contributions of ～ 45% and ～ 70%, respectively. Through the yields of secondary products from the oxidation of MACR and MVK by the OH radical and the concentrations of MACR and MVK, it was found that methylglyoxal and formaldehyde were the main oxidation products of MACR and MVK at the HS site. Overall, this study evaluated the roles of primary emissions on ambient levels of MACR and MVK and advanced the understanding of photochemical oxidation of MACR and MVK in the PRD.

关键词： Source apportionment methacrolein Methyl vinyl ketone Pearl River Delta

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High dispersion of heteropolyacid nanoparticles on hydrothermally Cs-modified three-dimensionally ordered macroporous SiO2 with excellent selectivity in methacrolein oxidation

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2785-2791页

作者： Heng Zhang Junqi Liu Chenyuan Liu Tingting Wang Wancheng Zhu School of Chemistry and Chemical Engineering Qufu Normal UniversityQufu 273165China

Heteropolyacid nanoparticles(NPs)were supported on Cs-modified three-dimensionally ordered macroporous(3DOM)SiO2 and used as the catalyst for the oxidation of methacrolein(MAL)to methacrylic acid(MAA).Hydrothermal treatment and incipient wetness impregnation were employed respectively for the Cs-modification.It was found that hydrothermal Cs-modification of 3DOM SiO2 promoted the dispersion of the supported heteropolyacid,which showed an average particle size of 5.2 nm,much smaller than that(17.6 nm)on the Csmodified 3DOM SiO2 prepared by incipient wetness impregnation.The effects of hydrothermal treatment on the structure and catalytic performance of the catalyst were investigated.Results showed that the ion exchange between Cs+and the surface silanol groups on 3DOM SiO2 was promoted with the increase of the hydrothermal temperature.Meanwhile,Cs-modification helped the heteropolyacid to retain intact Keggin structure,inhibiting the formation of MoO3.Highly dispersed heteropolyacid NPs with enhanced structural stability exhibited excellent selectivity to MAA in the oxidation of MAL.

关键词： Catalyst support Heteropolyacid Nanoparticles Oxidation methacrolein

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The Intermetallic Catalysts for Oxidative Esterification of methacrolein to Methyl Methacrylate

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过程工程学报 2006年第4期6卷 661-665页

作者：董海锋李增喜王正平赵威刁琰琰张锁江 Institute of Process Engineering Chinese Academy of Sciences School of Chemical Engineering Harbin Engineering University Harbin Heilongjiang 150001 China School of Chemical Engineering Harbin Engineering University

A series of supported intermetallic Pb-Pb catalysts were prepared with the impregnation method by changing the support(silica,molecular sieve or γ-alumina)and the pore size.The chemical states of the two metals were characterized by XPS analysis,the process for producing methyl methacrylate based on the direct oxidative esterification of methacrolein with methanol in the presence of oxygen was performed in a slurry reactor with the above-mentioned catalysts.The influence of the calcination temperature and the kinds of support as well as the pore size on catalytic activity had been extensively investigated.Under the conditions of temperature at 80℃,catalyst 3.8%(ω)and the reaction time 2 h,the conversion rate of methacrolein reached 85%,the selectivity and the yield of methyl methacrylate were 90% and 76.5%,respectively.

关键词： methyl methacrylate methacrolein Pd-Pb catalyst oxidative esterification

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Transition metal-doped heteropoly catalysts for the selective oxidation of methacrolein to methacrylic acid

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Frontiers of Chemical Science and Engineering 2016年第1期10卷 139-146页

作者： Yanxia Zheng Heng Zhang Lei Wang Suojiang Zhang Shaojun Wang School of Light Industry and Chemical Engineering Dalian Polytechnic University Dalian 116034 China Beijing Key Laboratory of Ionic Liquids Clean Process Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Chemistry and Chemical Engineering Qufu Normal University Qufu 273165 China

Heteropoly compounds with the general formula Cs1Mo.5X＋H3-o.5xP1.2MOllVO4o （M = Fe, Co, Ni, Cu or Zn） and CslCuyH3_2yP1.2MO11VO40 （y = 0.1, 0.3 or 0.7） were synthesized and then used as catalysts for the selective oxidation of methacrolein to methacrylic acid. The effects of the transition metals on the structure and activity of the catalysts were investigated. FTIR spectra showed that the transition metal-doped catalysts main- tained the Keggin structure of the undoped catalysts. X-ray diffraction results indicated that before calcination, the catalysts doped with Fe and Cu had cubic secondary structures, while the catalysts doped with Co, Ni or Zn had both triclinic and cubic phases and the Co-doped catalyst had the highest content of the triclinic form. Thermal treatment can decrease the content of the triclinic phase. NH3 temperature-programmed desorption and H2 tem- perature-programmed reduction results showed that the transition metals changed the acid and redox properties of the catalysts. The addition of Fe or Cu had positive effects on the activities of the catalyst which is due to the improvement of the electron transfer between the Fe or Cu and the Mo. The effects of the copper content on structure and catalytic activity were also investigated. The CSlCUo.3H2P1.2MO11VO40 catalyst had the best performance for the selective oxidation of methacrolein to methacrylic acid.

关键词： heteropoly compounds transition metals selective oxidation methacrolein

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Photooxidation of methacrolein in Fe(III)-Oxalate Aqueous System and Its Atmospheric Implication

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Advances in Atmospheric Sciences 2021年第7期38卷 1252-1263页

作者： Yu WANG Jie ZHAO Huihui LIU Yuan LI Wenbo DONG Yanlin WU Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention Department of Environmental Science&EngineeringFudan UniversityShanghai 200438China Shanghai Institute of Pollution Control And Ecological Security Shanghai 200092China

Iron and oxalic acids are widely distributed in the atmosphere and easily form ferric oxalate complex(Fe(III)-Ox).The tropospheric aqueous-phase could provide a medium to enable the photo-Fenton reaction with Fe(III)-Ox under solar irradiation.Although the photolysis mechanisms of Fe(III)-Ox have been investigated extensively,information about the oxidation of volatile organic compounds(VOC),specifically the potential for Secondary Organic Aerosol(SOA)formation in the Fe(III)-Ox system,is lacking.In this study,a ubiquitous VOC methacrolein(MACR)is chosen as a model VOC,and the oxidation of MACR with Fe(III)-Ox is investigated under typical atmospheric water conditions.The effects of oxalate concentration,Fe(III)concentration,MACR concentration,and pH on the oxidation of MACR are studied in detail.Results show that the oxidation rate of MACR greatly accelerates in the presence of oxalate when compared with only Fe(III).The oxidation rate of MACR also accelerates with increasing concentration of oxalate.The effect of Fe(III)is found to be more complicated.The oxidation rate of MACR first increases and then decreases with increasing Fe(III)concentration.The oxidation rate of MACR increases monotonically with decreasing pH in the common atmospheric water pH range or with decreasing MACR concentration.The production of ferrous and hydrogen peroxide,pH,and aqueous absorbance are monitored throughout the reaction process.The quenching experiments verify that·OH and O_(2)^(+)are both responsible for the oxidation of MACR.MACR is found to rapidly oxidize into small organic acids with higher boiling points and oligomers with higher molecular weight,which contributes to the yield of SOA.These results suggest that Fe(III)-Ox plays an important role in atmospheric oxidation.

关键词： Fe(III)-Ox OH radical atmospheric oxidation SOA methacrolein

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Effect of Bi promoter on the performances of selective oxidation of isobutane to methacrolein over MoVO/AlPO_4 catalysts

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Journal of Natural Gas Chemistry 2012年第2期21卷 165-169页

作者： Xitao Wang Mei Li Fen Wang Shunhe Zhong Shi Jiang Sihe Wang Tianjin Key Laboratory of Applied Catalysis Science and Technology College of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Nature Gas Company Dagang Oil FieldTianjin 300280China

The effects of Bi on the catalytic performance of selective oxidation of isobutane to methacrolein over MoVO/AlPO4 catalyst were investigated by XRD, FT-Raman, XPS, UV-vis DRS techniques. The results show that the addition of Bi component into the MoVO/AlPO4 catalyst obviously improves the catalytic performance, and the selectivity to methacrolein can increase from 14.2% to 45.1% with the increase of Bi/V molar ratio from 0 to 1. Combining the characterization results with the reaction evaluation, it is concluded that the catalytic activities of the MoV0.3Bix/AlPO4 catalysts are related to the crystalline phase composition and the dispersion of molybdenum and vanadium oxides species in general, and also to the V5＋/V4＋ molar ratio on the surface in particular.

关键词： sol-gel method selective oxidation of isobutene methacrolein MoVBiO/AlPO4 catalyst

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Oxidative Esterification of methacrolein to Methyl Methacrylate over Supported Palladium Catalyst

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Chinese Chemical Letters 2006年第6期17卷 739-742页

作者： Wei ZHAO Wei Guo CHENG Zeng Xi LI Lei WANG Xiang Ping ZHANG Suo Jiang ZHANG Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 Graduate University of Chinese Academy of Sciences Beijing 100049

Supported palladium catalysts, which were used in the oxidative esterification of methacrolein to methyl methacrylate, have been prepared with different carriers and Pd precursors. Experimental results revealed that Pd catalysts with r-Al2O3 support and Na2PdC14 precursor showed good performance. Pd catalyst modified with Pb and Mg indicated that Pd-Mg bimetallic catalyst exhibited considerably higher activity and Pd-Pb exhibited both higher activity and selectivity. 92.27% methacrolein conversion and 90.57% methyl methacrylate selectivity were obtained on Pd-Pb-Mg catalyst.

关键词： Oxidative esterification methacrolein methyl methylcralate palladium alumina.

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Insights into the Reaction Network and Mechanism of Green Aerobic Oxidative Esterification of methacrolein over Different Heterogeneous Catalysts

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China Petroleum Processing & Petrochemical Technology 2021年第3期23卷 1-11页

作者： Li Chenhao Xia Changjiu Liu Yujia Huang Kaimeng Peng Xinxin Liu Jinsheng Lin Min Zhu Bin Luo Yibin Shu Xingtian State Key Laboratory of Catalytic Materials and Reaction Engineering Research Institute of Petroleum ProcessingSINOPECBeijing 100083

The oxidative esterification of methacrolein(MAL)is an important way to prepare high-valued methyl methacrylate(MMA),but this process is ultra-complex due to the high reactivity of both C=O and C=C bonds in MAL molecule.In order to further improve MMA selectivity,the reaction network and relevant mechanisms have been proposed and profoundly investigated in this paper.Five kinds of fundamental reactions are involved in this process,including(a)the acetal reaction;(b)the aerobic oxidation of hemiacetal;(c)the alkoxylation of C=C double bond;(d)the Diels-Alder reaction;and(e)the hydrogenation reaction of unsaturated double bond.Among them,the Diels-Alder reaction of MAL is non-catalyzed,and the Brönsted acid sites or the Lewis acid sites favor promoting acetal reaction of MAL with methanol,while the alkoxylation of C=C bond with methanol is enhanced under alkaline condition.In particular,by employing the Pd-based catalysts,hydrogenation products are formed in alkaline methanol solution,hence with lower than those obtained by the Au-based catalysts.Notably,it is necessary to match the hemiacetal fromation and aerobic oxidation of hemiacetal,which is relevant with the amount and strength of acid and redox sites.Consequently,this work can provide a good guidance for the further design of both catalysts and processes in future.

关键词： methacrolein oxidative esterification mechanism reaction network methyl methacrylate

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Selective Oxidation of Isobutane over NH_4CsFePVMoAs Heteropolycompound Catalysts

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Journal of Natural Gas Chemistry 2005年第1期14卷 54-60页

作者： TiejunCai ZhengjunFang QianDeng ZhenshanPeng DepartmentofChemistryandChemicalEngineering HunanUniversityofScienceandTechnologyXiangtan411201China

A series of NH_4Cs_(1.5)Fe_(0.08)H_xPVMo_(11)As_aO_y heteropolycompoundcatalysts for the selective oxidation of isobutane, having Keggin structure, were synthesized byusing co-precipitation method. The catalysts were characterized by FT-IR, H_2-TPR, TG-DTA, SEM andXRD. Effects of the As content, reaction time, reaction temperature and molar ratio of isobutane tooxygen in feedstock on the activity and selectivity of the catalyst were investigated. Theactivation energy of the catalysts was measured by kinetics researches. Results showed theintroduction of Cs^+ into the catalysts shortened the stable period of them and enhanced theircatalytic activity for the selective oxidation of isobutane. The highest conversion of isobutane andthe total selectivity to liquid products were 18.6% and 81.2%, respectively, which were obtained at380℃ with a space velocity of 975 h^(-1) over the NH_4Cs_(1.5)Fe_(0.08)H_xPVMo_(11) As_(0.3)O_yheteropolycompound catalyst. It is confirmed that completely oxidized products were controlled well.

关键词： heteropolycompound catalyst isobutane selective oxidation methacrylicacid methacrolein

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