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1Microwave-assisted catalytic oxidation of gaseous toluene with a Cu-Mn-Ce/cordierite honeycomb catalyst显示文摘A novel Cu-Mn-Ce/cordierite honeycomb catalyst was prepared by an incipient wetness method and the catalyst was characterized. The active ingredients were present as various spinel species of Cu, Mn and Ce oxides with different valences and they were unevenly dispersed over the surface of the catalyst. The catalytic oxidation of gaseous toluene was primarily investigated using a fixed bed reactor under microwave heating in the continuous flow mode. Under the optimal conditions of 6.7 wt-% loading of the active component, a bed temperature of 200℃, a flow rate of 0.12 m^3 · h^-1 and an initial concentration of toluene of 1000 mg·m^-3, the removal and mineralization efficiencies of toluene were 98% and 70%, respectively. Thus the use of the microwave effectively improved the oxidation of toluene and this is attributed to dipole polarization and hotspot effects. After four consecutive cycles (a total of 1980 min), the Cu-Mn- Ce/cordierite catalyst still exhibited excellent catalytic activity and structural stability, and the toluene removal was higher than 90%. This work demonstrates the possibility of treating volatile organic compounds in exhaust gases by microwave-assisted catalytic oxidation.Longli Bo Shaoyuan Sun 2019Frontiers of Chemical Science and Engineering2019,13,2:11
2Catalyst design strategies towards highly shape-selective HZSM-5 for paraxylene through toluene alkylation显示文摘With the shape selective zeolite catalyst,toluene alkylation with methanol to para-xylene(MTPX)technology could produce highly pure para-xylene(PX)in one step.The lower feedstock cost and less energy consumption in products separation make it more competitive compared to the current toluene disproportionation route.Thus,MTPX is regarded as the most reasonable production route for PX production.This article reviews the strategies that applied to the preparation of high-performance catalysts for MTPX,with special focus on the precise control of pore dimension and acid sites distribution in zeolite to achieve the highest selectivity to PX.The outlook of the MTPX catalyst is also proposed to guide the catalyst development in the field.Xin Huang Ruizhuang Wang Xu Pan Chuanfu Wang Maohong Fan Yufei Zhu Yonggang Wang Jin Peng 2020Green Energy & Environment2020,5,4:10
3Promoting ring-opening efficiency for suppressing toxic intermediates during photocatalytic toluene degradation via surface oxygen vacancies显示文摘Aromatic ring-opening process is well recognized as the rate-determining step for catalytic toluene degradation. In photocatalytic toluene degradation, the toxic intermediates w让h harmful effects may be generated. To clarify the precise reaction mechanism and control the toxic intermediates generation, a closely combined in situ DRIFTS and DFT calculation is utilized to address these important issues. We construct the BiOCl w让h oxygen vacancies (OVs) and reveal the structure of OVs. The defect level caused by oxygen vacancies could promote the light adsorption and charge separation, which further boosts the activation of ring-opening species and enhances the generation process of free radicals. The reaction energy barriers of four possible ring-opening processes on defective BiOCl (OVBOC) are all declined in comparison with perfect BiOCl (BOC). The existence of oxygen vacancies could smooth the ratedetermining step so the ring-opening efficiency of photocatalytic toluene degradation is highly increased. Most importantly, the methyl species would be further oxidized and tend to open the benzene-ring at benzoic acid on BOC while the ring would be broken at the benzyl alcohol on OVBOC. These results indicate that the toluene degradation pathway is shortened via the surface OVs, which enables the production of radicals with high oxidation capability for the accelerated chain scission of the ring-opening intermediates. Finally, the efficiency of the key ring-opening process could be enormously improved and toxic intermediates are effectively restrained. The present work could provide new insights into the design of high-performance photocatalysts for efficient and safe degradation of VOCs in air.Xing'an Dong Wen Cui Hong Wang Jieyuan Li Yanjuan Sun Haiqiang Wang Yuxin Zhang Hongwei Huang Fan Dong 2019Science Bulletin2019,64,10:9
4LaZn_xFe_(1-x)O_3钙钛矿型纳米催化剂的制备、表征及其甲苯燃烧性能(英文)显示文摘Nanostructured LaFeO3 and substituted LaZnxFe1-xO3(x = 0.01,0.05,0.1,0.2,and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of toluene.Their structures and surface properties were investigated by X-ray diffraction,Fourier transmission infrared spectroscopy,BET surface area,and scanning electron microscopy.Characterization data revealed that the total insertion of zinc into LaFeO3 takes place when x ≤ 0.1.However,ZnO segregation occurs to some extent,especially at x > 0.1.The performance of these perovskites was evaluated by toluene combustion.The catalytic activity of the catalysts increased substantially with an increase in zinc substitution.These results can be attributed to the cooperative effect between LaZnxFe1-xO3 and the zinc oxide phases.The relative concentration of these phases determines their oxygen activation ability and reactivity.Seyed Ali HOSSEINI Mohammad Taghi SADEGHI Abdolali ALEMI Aligholi NIAEI Dariush SALARI Leila KAFI-AHMADI 2010催化学报2010,31,7:7
5SYNTHESIS AND CHARACTERIZATION OF NOVEL MULTIFUNCTIONAL HOST COMPOUNDS.1.β-CYCLODEXTRIN DERIVATIVE BEARING DIETHANOLAMINE MOIETY显示文摘A novel β-cyclodextrin(β-CD)derivative bearing diethanolamine moietywas synthesized by a convenient method with 63% yield,and the new host compound wascharacterized by (13)~C-NMR,FT-IR spectra etc,Bao Jian SHEN Lin Hui TONG Dao Sen JIN Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou,730000 1991Chinese Chemical Letters1991,2,3:7
6Experimental study of Iranian heavy crude oil viscosity reduction by diluting with heptane, methanol, toluene, gas condensate and naphtha显示文摘Due to the high viscosity of heavy crude oils,production from these reservoirs is a demanding task.To tackle this problem,reducing oil viscosity is a promising approach.There are various methods to reduce viscosity of heavy oil:heating,diluting,emulsification,and core annular flow.In this study,dilution approach was employed,using industrial solvents and gas condensate.The viscosity of two Iranian heavy crude oils was measured by mixing with solvents at different temperatures.Dilution of both oil samples with toluene and heptane,resulted in viscosity reduction.However,their effect became less significant at higher concentrations of diluent.Because of forming hydrogen bonds,adding methanol to heavy crude oil resulted in higher viscosity.By adding condensate,viscosity of each sample reduced.Gas condensate had a greater impact on heavier oil;however,at higher temperatures its effect was reduced.Diluting with naphtha decreased heavy oil viscosity in the same way as n-heptane and toluene.Besides experimental investigation,different viscosity models were evaluated for prediction of heavy oil/solvent viscosity.It was recognized that Lederer'model is the best one.Amir Hossein Saeedi Dehaghani Mohammad Hasan Badizad 2016Petroleum2016,2,4:6
7Detection of hydroxyl radical in plasma reaction on toluene removal显示文摘A new method was introduced to detect the concentration of OH radical in dielectric barrier discharge(DBD)reaction.A film, which was impregnated with salicylic acid,was used to detect OH radical in plasma reaction at room temperature and atmospheric pressure.Salicylic acid reacts with OH radical and produces 2,5-dihydroxybenzoic acid(2,5-DHBA).Then,a high performance liquid chromatography(HPLC)was carried out to detect the concentration of 2,5-DHBA.Therefore,OH radical in nonthermal plasma reaction could be calculated.In this plasma reaction,the applied voltage was controlled at 10 kV,the initial concentration of toluene was 400 mg/m3,and the gas flow rate was 300 ml/min.It was observed that when the film was placed away from the plasma area,2,5-DHBA could not be detected by HPLC,although the sampling time lasted for 48 h.On the other hand,when the film was placed in the plasma area and the sampling time being too long(>4 h),the concentration of 2,5-DHBA was also below detection limit,and it could not be detected by HPLC.However,when the film was placed in the plasma reaction field with the sampling time being 3 h,the concentration of OH radical was calculated to be 10.54×1012 cm-3.In addition,concentration of OH radical was investigated under different humidity,such as 0.2%,0.4%,0.6%,0.8%,and 1.0%.The results showed that the amount of OH radical stayed at order of magnitude of 1012 cm-3 and increased with the increase of humidity.Guo Yufang Liao Xiaobin Ye Daiqi 2008Journal of Environmental Sciences2008,20,12:5
8Photocatalytic oxidation of gaseous benzene,toluene and xylene under UV and visible irradiation over Mn-doped TiO_(2)nanoparticles显示文摘The photocatalytic oxidation of gaseous benzene,toluene and xylene(BTX)over un-doped,0.1 and 1 wt%Mn-TiO_(2)nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert gas.The photocatalytic decomposition efficiency and the oxidation products were determined using a Static Photochemical Reactor coupled with FTIR spectroscopy.BTX underwent efficient decomposition over Mn-TiO_(2)photocatalysts under UV irradiation,more with oxygen presence and less without oxygen.More important toluene and xylene went substantial decomposition over 0.1 mol%Mn-TiO_(2)under visible irradiation with oxygen presence.The main final oxidation products in the UV photocatalysis of BTX were CO_(2),CO and H2O,with CO_(2) and CO yields 4 and 2 respectively.The conversion percentage of benzene,toluene,and xylene to CO_(2) were 63.6%,56.4%,51.8%,and to CO 29%,26.5%,23.2%,respectively.In the visible photocatalysis of toluene and xylene the yields of CO were insignificant.Formation of carbon containing deposits on TiO_(2)surfaces was observed after extensive UV photocatalysis of toluene and xylene,and such by-products surface coverage may reduce the photocatalytic activity of TiO_(2)samples.Some aspects of the photocatalytic mechanism were examined.Vassilios Binas Vassilis Stefanopoulos George Kiriakidis Panos Papagiannakopoulos 2019Journal of Materiomics2019,5,1:5
9Lanthanum-doped Cu-Mn composite oxide catalysts for catalytic oxidation of toluene显示文摘CuMn mixed oxides catalysts doped with La were prepared following a co-precipitation method and used for the catalytic oxidation of toluene. Catalysts properties of the catalysts were investigated by X-ray diffraction, N_2 adsorption/desorption,scanning electron microscopy, H_2-temperature-programmed reduction(H_2-TPR), O_2-temperature-programmed desorption(O_2-TPD) and X-ray photoelectron spectroscopy techniques. Characterization data reveal that the phase change and decrease in crystallinity of the La-doped catalysts increase the number of oxygen vacancies. Improvements in reducibility and an increase in the amount of chemisorbed oxygen of the La-doped catalysts were also verified by H_2-TPR and O_2-TPD. The activity of the CuMn mixed oxides catalysts is significantly improved by the addition of a nominal amount of La. The CuMn/La-4 mol% catalyst exhibits the best catalytic activity, with a 90%conversion temperature of 255 ℃,attributed to a high Mn^(3+)ratio, superficial chemisorbed oxygen,and high surface area. This study indicates La to be a promising dopant for Cu-Mn catalysts toward toluene oxidation.Jing Pan Wentao Du Yongjun Liu Yan Cheng Shandong Yuan 2019Journal of Rare Earths2019,37,6:5
10铂和HF掺杂的H-ZSM-5分子筛催化甲苯与甲醇烷基化反应(英文)显示文摘Toluene was alkylated with methanol in a flow type reactor at temperatures between 300 and 500 °C using H-ZSM-5 zeolite, 0.2%Pt/H-ZSM-5 and hydrofluorinated 0.2%Pt/H-ZSM-5 with HF concentrations of 1.0%, 2.0%, 3.0%, or 4.0%. Pt primarily enhances toluene conversion, total xylenes production, and p-xylene relative to its thermodynamic equilibrium. As the concentration of HF increases from 1.0% to 3.0%, the catalyst activity increases because of the increase in the number of acid sites and their strength. Additionally, the surface area and Pt dispersion also increases. An advantage of increased HF doping is that the formation of voluminous trimethylbenzene (TMB) byproducts is inhibited. However, at a HF concentration of 4.0%, Al and Si are partially leached and then deposited mostly in the wider catalytic pores. This was determined by evaluating the pore volume distribution and we determined that reactivity inhibition was ob-viously present and was due to diffusion restriction.Ahmed K. ABOUL-GHEIT Ateyya A. ABOUL-ENEIN Ahmed E. AWADALLAH Salwa A. GHONEIM Eman A. EMAM 2010催化学报2010,31,10:4
11SYNTHESIS AND CHARACTERIZATION OF AMPHIPHILIC GRAFT COPOLYMER CONTAINING MICROPHASE SEPARATED AND LONG POLY(ETHYLENE OXIDE) SIDE CHAIN STRUCTURES显示文摘Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution’, the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.邱永兴 俞小洁 封麟先 杨士林 1993Chinese Journal of Polymer Science1993,11,1:4
12顶空固相微萃取/气相色谱-质谱法检测胶乳中痕量甲苯的研究显示文摘 合成胶乳是合成橡胶的一个重要组成部分,而合成胶乳中丁苯胶乳又占主导地位.丁苯胶乳是由丁二烯(B)和苯乙烯(S)经过乳液聚合得到的一种固体含量为30%~50%的水性乳液.由于这种水性乳液具有橡胶的韧性,所以作为增强剂被广泛应用于造纸、涂料、纺织、建筑和粘合剂等各个领域,与人们的生活环境密切相关[1~3].……宋国新 吴丹 胡耀铭 2004分析测试学报2004,23,z1:4
13Effects of cerium precursors on surface properties of mesoporous CeMnO_x catalysts for toluene combustion显示文摘Mesoporous CeMnOx composite oxides catalysts were prepared by surfactant-assisted co-precipitation method and used for the catalytic oxidation of toluene.The effect of different cerium precursors[Ce(NO3)3 and(NH4)2 Ce(NO3)6] on catalyst structure,surface properties and toluene combustion activities of mesoporous CeMnOx catalysts were investigated.The Ce(Ⅲ)MnOx catalyst prepared from Ce(NO3)3 precursor shows higher catalytic activity,with a 90% conversion temperature of 240℃,which is better than the Ce(Ⅳ)MnOx catalyst derived from[(NH4)2 Ce(NO3)6] precursor.On the basis of characterizations,it reveals that abundant surface content of Mn4+,better redox behavior and larger concentration of surface active oxygen species are responsible for the excellent catalytic performance.Changyu Zhang Wei Chu Feng Chen Lei Li Ruiyu Jiang Jinlong Yan 2020Journal of Rare Earths2020,38,1:4
14Comparative study of degradation of toluene and methyl isobutyl ketone(MIBK)in aqueous solution by pulsed corona discharge plasma显示文摘Effectiveness of pulsed power plasma for the degradation of two toxic volatile organic compounds(VOCs),toluene and methyl isobutyl ketone(MIBK),in aqueous solution was evaluated.The plasma degradation of MIBK has been studied for the first time.The influence of initial concentration of target compound,solution pH and scavengers on percentage degradation was evaluated.100%removal of 200 mg/L of toluene and MIBK was achieved both in liquid and gaseous phases after 12 and 16 min of plasma treatment,respectively.The first order rate constant of toluene and MIBK degradation(for 200 mg/L each)was 0.421 and 0.319 min~(-1)respectively when they were treated individually,and these values decreased slightly during degradation of their mixture.MIBK degradation was slower than toluene and it might be due to semi volatile and hydrophilic nature of MIBK.The effect of initial concentration of toluene and MIBK showed different degradation patterns.Highest degradation of both the compounds was obtained in neutral pH and in absence of scavengers.·OH radical was the major reactive species involved in their degradation.Their degradation in real environmental matrices showed that removal reduced significantly in secondary effluent due to scavenging of reactive species by various ions and organic matter.The total number of degradation intermediates identified in case of toluene and MIBK was 11 and 14 respectively and formate was the one recalcitrant byproduct generated.The degradation pathway of toluene and MIBK involving reactions of reactive oxygen and nitrogen species and reductive species is proposed.Jerin Jose Ligy Philip 2021Journal of Environmental Sciences2021,33,3:4
15Preparation and characterization of novel carbon molecular sieve membrane/PSSF composite by pyrolysis method for toluene adsorption显示文摘Carbon molecular sieve membrane(CMSM)/paper-like stainless steel fibers(PSSF)has been manufactured by pyrolyzing poly(fiirfuryl alcohol)(PFA)coated on the metal fibers.PFA was synthesized using oxalic acid dihydrate as a catalyst and coated on microfibers by dip coating method.For the purpose of investigating the effects of final carbonization temperature,the composites were carbonized between 400℃ and 800℃ under flowing nitrogen.The morphology and microstructure were examined by X-ray diffraction,Fourier transforms infrared spectroscopy,scanning electron microscopy,thermogravimetric analysis,N2 adsorption and desorption,Raman spectra and X-ray photoelectron spectra.The consequences of characterization showed that the CMSM containing mesopores o f 3.9 nm were manufactured.The specific surface area of the CMSM/PSSF fabricated in different pyrolysis temperature varies from 26.5 to 169.1 m^2·g^-1 and pore volume varies from 0.06 to 0.23 cm^3·g^-1.When pyrolysis temperature exceeds 600℃,the specific surface,pore diameter and pore volume decreased as carbonization temperature increased.Besides,the degree of graphitization in carbon matrix increased with rising pyrolysis temperature.Toluene adsorption experiments on different structured fixed bed that was padded by CMSM/PSSF and granular activated carbon(GAC)were conducted.For the sake of comparison,adsorption test was also performed on fixed bed packed with GAC.The experimental results indicated that the rate constant κ′ was dramatically increased as the proportion of CMCM/PSSF composites increased on the basis of Yoon-Nelson model,which suggested that structured fixed bed padded with CMSM/PSSF composite offered higher adsorption rate and mass transfer efficiency.Ying Yan Peng Huang Huiping Zhang 2019Frontiers of Chemical Science and Engineering2019,13,4:4
16A Theoretical Study on Pyrolysis and Sensitivity of Energetic Compounds(Ⅴ)──Nitro Derivatives of Methylbenzene显示文摘UHF-SCF-AM1 MO calculations were performed for two kinds of pyrolysis reactions of seven nitro derivatives of methylbenzene(homolysis reactions by the rupture of bond C-NO2 into radicals and isomerization reactions in the way of methyl H transferring to the ortho nitro O atom). The molecular geometries of the reactants, the transition states and the products of the fourteen reactions were fully optimized. The activation energies for these two kinds of reactions have been obtained. The results indicate that this category of compounds is more easily pyrolyzed by being initiated via isomerization reactions. A parallel relationship exists between the activation energy of the isomerization reactions and the impact sensitivity of the seven titled compounds.GU Zhi-ming FAN Jian-fen XIAO He-ming and DONG Hai-shan (Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, P. R. China Department of Chemistry, Suzhou University, Suzhou 215006, P. R. China Institute of Chemical M 2000Chemical Research in Chinese Universities2000,16,1:4
17Mn-Co oxide decorated on Cu nanowires as efficient catalysts for catalytic oxidation of toluene显示文摘Mn-Co mixed oxides were electrodeposited on Cu nanowires generated on Cu foam(CF)and used for effectively catalytic oxidation of toluene.The physical and chemical properties of the prepared catalysts were characterized by SEM,TEM,XRD,H_(2)-TPR,O_(2)-TPD and XPS.It is found that the Mn-Co mixed metal oxides were uniformly coated on the Cu nanowires by the electrochemical method,whose Mn/Co ratio can be tuned by adjusting the molar ratio of Mn/Co in the initial solution for the electrodeposition.The intimate contact between Mn and Co nanocrystals was found by HRTEM,which is important for realizing synergetic effects on improving catalytic activity.Meanwhile,the formation of the active surface oxygen species and the increase of the active species of Mn^(4+)and Co^(3+)were considered to make significant contribution to the catalytic oxidation of toluene.Mn-Co mixed metal oxide catalysts exhibited higher performance than the single metal oxide,and especially 0.10Mn-0.01Co/CF catalyst with the Mn/Co molar ratio of 10:1 in the initial solution for the electrodeposition achieved the highest catalytic activity with a low toluene conversion temperature(T_(90%))of 251℃,and displayed excellent catalytic stability even in the presence of water vapor.It is expected that such a simply-electrodeposited mixed metal oxides based catalysts could be applied for the oxidation of volatile organic compounds(VOCs)in a practical process.Jing Wang Peifen Wang Akihiro Yoshid Qiang Zhao Shasha Li Xiaogang Hao Abuliti Abudula Guangwen Xu Guoqing Guan 2020Carbon Resources Conversion2020,3,1:4
18Removal of Toluene by Adsorption/Desorption Using Ultra-stable Y Zeolite显示文摘The adsorption performance of toluene on ultra-stable Y zeolite (USY) was studied via dynamic adsorption. The eff ects of bed temperature, initial concentration, and feed fl ow rate on adsorption were investigated. The Yoon-Nelson model was used to fi t the toluene breakthrough curves. The length of mass transfer zone was calculated based on breakthrough curves. The Langmuir-Freundlich model fi t the adsorption isotherms of toluene on USY, which indicated that the surface of USY was heterogeneous. The adsorption isosteric heat calculated from adsorption isotherms ranged from 54.3 to 69.8 kJ/mol, indicating physical adsorption. The combined technique of temperature swing adsorption with vacuum swing adsorption (TVSA) exhibited excellent desorption performance, which was attributed to the low desorption activation energy. Under optimized TVSA conditions, the desorption rate of toluene reached 90.6% within 10 min. The long-term cyclic utilization results indicated that the adsorption capacity of USY was stable.Lei Xu Yonghong Li Jiang Zhu Zhiyuan Liu 2019Transactions of Tianjin University2019,25,4:3
19Catalyst assisted destruction of trichloro ethylene and toluene in corona discharges显示文摘IntroductionTrichloroethyleneisaveryeffectivesolventtoremoveoilfromsiliconandothermaterialsusedinsemiconductorindustry.TheC2HC...Muhammad Arif Malik, JIANG Xuan\|zhen (Department of Chemistry, University of Zhejiang, Hangzhou 310027, China) Foundation item: National Natural Science Foundation of China (No. 29576261) 2000Journal of Environmental Sciences2000,12,1:3
20SOLID STATE VOLTAMMETRY OF ELECTROACTIVE SOLUTES IN POLYMER SOLVENTS(PEO)AT MICROELECTRODE显示文摘The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly(ethylene oxide)(PEO) film can be used as gas sensor.Guang Li CHE and Shao Jun DONG* Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Academia Sinica, Changchun, 130022 1993Chinese Chemical Letters1993,4,5:2
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