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Effect of alkali treatment on the Structure and Catalytic Properties of ZSM-5 Zeolite

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Chinese Chemical Letters 2005年第1期16卷 115-118页

作者： ZiYunLI XinSUN QiangXIAO ShouHeXIANG CollegeofChemistry NankaiUniversityTianjin300071

Catalytic properties of ZSM-5 zeolite samples pretreated with NaOH solution have been investigated. The samples are characterized by XRD, SEM, chemical analysis, and N2 adsorption. The results indicate that mesopores are created in ZSM-5 crystals under alkali treatment without change the microporous structure and acidic strength of the zeolite, but the crystallinity is greatly decreased under severe treatment. IR indicates that the concentration of silanol is greatly enriched by alkali treatment. The etherification activities of ZSM-5 zeolites are greatly increased by alkali-treatment. The noticeably improved catalytic activity of treated samples is ascribed to the formation of mesopores and greatly enriched silanol group.

关键词： alkali treatment ZSM-5 zeolite ETBE etherification.

Corn Husk Fiber Preparation and Morphology with alkali treatment

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Journal of Donghua University(English Edition) 2016年第4期33卷 574-578页

作者：严涛海李永贵张默涵蒋金华陈南梁 Clothing and Design Faculty Minjiang University College of Textiles Donghua University

The corn husks were usually discarded as useless materials,after alkali treatment from which the corn husk fiber was obtained. The corn husk fiber included half degumming corn husk bundle fiber and corn husk single fiber. This study found that corn husk single fiber was a kind of cellulose fiber,and was obtained with the fully alkali treatment technique,the process of which was NaOH concentration 0.15 g/mL,temperature at 80℃,and reaction time about 2.5 h. The morphologies of corn husk single fibers presented nature convolutions along with the fiber axis. They were closed at both ends,and they had a pentagram cavity and oval-shaped crosssection. They were flat shape,the fineness of the fibers was close to cotton fiber,and the mechanical properties of the fibers were similar to hemp fiber. So the corn husk fibers could be predicted that they could be used in textile industry because their properties were very close to cotton fiber or flax fiber.

关键词： corn husk fiber alkali treatment morphology property

Effects of fiber mass fraction and alkali treatment on mechanical properties of biodegradable composites

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Effects of fiber mass fraction and alkali treatment on mecha...

PREPARATION OF HOLLOW LATEX PARTICLES BY alkali-ACID treatment

第九届中国林业青年学术年会

作者： zhi-yong Qin 1 Yi-qiang Wu 2 Yan Qing 3 (School of Materials Science and Engineering Central South University of Forestry and Technology,Hunan Changsha, P.R.China 410000)

Biodegradable composites of poly lactic acid reinforced with wood fiber are fabricated by using twin screw extruder followed by the injection molding *** effects of fiber mass fraction and alkali concentration on mechanical properties of biodegradable composites are *** results show that through carrying out the TG analysis of wood fiber,the most suitable temperature for composite materials processing is about 160℃is chosen,the mechanical properties of biodegradable composites presented tendency which reduced first,elevated,and again reduced along with fiber mass fraction increased,after the alkali treatment,the mechanical properties of biodegradable composites have the tendency which increased first and then reduced,when the concentration of alkali solution is 8%, both the tensile strength and impact strength are *** scanning electron microscope and Infrared Spectrum Analysis are also used for examination of the wood fiber and biodegradable composites.

关键词： wood fiber mass fraction alkali treatment mechanical properties Infrared spectrum analysis

来源： cnki会议评论

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Journal of Shanghai Jiaotong university(Science) 2001年第1期6卷 10-15页

作者：郝冬梅王新灵朱卫华唐小真刘成岑施凯 School of Chemistry and Chemical Tech. Shanghai Jiaotong Univ. Dept. of Chemistry Eng. Taiyuan Univ. of Tech.

Hollow polymer latex particles were prepared by seeded emulsion polymerization. A seed latex consisting of styrene (St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) were then carried out in the absence of surfactant. Final latex was treated by a two step treatment under alkaline and acidic conditions, thus, the particles with hollow structure were obtained. We discussed the effects of pH value, temperature and time in alkali and acid treatment processes on hollow structure within the polymer latex particles and amount of carboxylic group on particle surface. The results show that the hollow polymer latex particles with the largest hollow size can be obtained under a certain condition (pH12.5, 90°C, 3 h in alkali treatment stage and pH2.5, 85°C, 3 h in acid treatment stage).

关键词： seeded emulsion polymerization hollow polymer particles alkali treatment acid treatment morphology

Effect of mesopore spatial distribution of HZSM-5 catalyst on zinc state and product distribution in 1-hexene aromatization

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Chinese Journal of Chemical Engineering 2024年第3期67卷 16-26页

作者： Chenhao Wei Di Gao Guohao Zhang Liang Zhao Jinsen Gao Chunming Xu The State Key Lab of Heavy Oil Processing China University of Petroleum(Beijing)Beijing 102249China SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China

1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking(FCC)gasoline to high-value benzene(B),toluene(T),and ***,the increasing market demand of xylene has put forward higher requirements for new generation of *** increasing xylene yield in 1-hexene aromatization,the effect of mesopore structure and spatial distribution on product distribution and Zn loading was *** with different mesopore spatial distribution were prepared by post-treatment of parent HZSM-5 zeolite,including NaOH treatment,tetra-propylammonium hydroxide(TPAOH)treatment,and *** was found the evenly distributed mesopore mainly prolongs the catalyst lifetime by enhancing diffusion properties but reduces the aromatics selectivity,as a result of damage of micropores close to the catalyst *** the selectivity of high-value xylene can be highly promoted when the mesopore is mainly distributed interior the ***,the state of loaded Zn was also affected by mesopores spatial *** the optimized catalyst,the xylene selectivity was enhanced by 12.4%compared with conventional Zn-loaded parent HZSM-5 catalyst at conversion over 99%.It was attributed to the synergy effect of mesopores spatial distribution and optimized acid *** work reveals the role of mesopores in different spatial positions of 1-hexene aromatization catalysts in the reaction process and the influence on metal distribution,as well as their synergistic effect two on the improvement of xylene selectivity,which can improve our understanding of catalyst pore structure and be helpful for the rational design of high-efficient catalyst.

关键词： 1-Hexene aromatization alkali treatment Xylene selectivity Mesopores Zinc state

Facile Surface Engineering of NiCo_(2)O_(4) to Boost Propane Oxidation Activity

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 19-26页

作者： Yang Jialei Wang Fengyi Lei Yang Zhang Mingchao Sun Shiqiang Xu Wenfan Ke Jiaxiang Wu Haojie Li Xingyun Qi Jian Institute of Materials for Energy and Environment College of Materials Science and EngineeringQingdao UniversityQingdao 266071China School of Chemistry and Chemical Engineering Hubei Key Laboratory of Coal Conversion and New Carbon MaterialsWuhan University of Science and TechnologyWuhan 430081China Department of Burn and Plastic Surgery Qingdao Municipal Hospital Affiliated to Rehabilitation UniversityQingdao 266000China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Spinel oxide(NiCo_(2)O_(4))has demonstrated great potential to replace noble metal catalysts for the oxidation reaction of air *** further boost the oxidation ability of such catalysts,in this study,a facile surface-engineering strategy wherein NiCo_(2)O_(4) was treated with different alkali solvents was *** obtained catalyst(NiCo_(2)O_(4)-OH)showed a higher surface alkalinity and more surface defects compared to the pristine spinel oxide,including enhanced structural distortion as well as promoted oxygen *** propane oxidation ability of NiCo_(2)O_(4)-OH was greatly enhanced,with a propane conversion rate that was approximately 6.4 times higher than that of pristine NiCo_(2)O_(4) at a reaction temperature 193℃.This work sets a valuable paradigm for the surface modulation of spinel oxide via alkali treatment to ensure a high-performance oxidation catalyst.

关键词： NiCo_(2)O_(4) surface defects alkali treatment propane oxidation

Chalcopyrite solar cells——state-of-the-art and options for improvement

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Science China(Physics,Mechanics & Astronomy) 2023年第1期66卷 3-17页

作者： S.Siebentritt T.P.Weiss Laboratory for Photovoltaics Department of Physics and Materials ScienceUniversity of LuxembourgBelvaux 4422Luxembourg

Chalcopyrite solar cells will have to play an important role to mitigate the climate crisis,because of their particularly low carbon *** in these semiconductors is due to native defects and intentional alkali *** recent progress in efficiency has been made possible by post-deposition treatments with heavy *** states and band gap distribution are the main limitations for the open circuit voltage in state-of-the-art chalcopyrite solar *** efficiency limitations are due to the increased diode factor because of metastable defect *** with Ag opens new possibilities of band-edge engineering,as well as seems to improve the diode *** state-of-the-art cells the back contact is passivated by a Ga gradient;considerable research has been done to passivate the back contact by structured or continuous dielectric layers.A leap forward in efficiency can be expected from tandem *** solar cells show promising potential as bottom cells as well as top cells.

关键词： doping tail states alkali treatment efficiency

Preparation of hierarchical mesoporous Zn/HZSM-5 catalyst and its application in MTG reaction

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Journal of Natural Gas Chemistry 2011年第3期20卷 237-242页

作者： Youming Ni Aiming Sun XiaolingWu Guoliang Hai Jianglin Hu Tao Li Guangxing Li School of Chemistry ＆ Chemical Engineering Huazhong University of Science ＆ Technology Wuhan 430074 Hubei China Hubei Key Laboratory of Materials Chemistry ＆ Service Failure Huazhong University of Science ＆ Technology Wuhan 430074 Hubei China

The hierarchical mesoporous Zn/ZSM-5 zeolite catalyst was prepared by NaOH treatment and Zn impregnation, and its application in the conversion of methanol to gasoline （MTG） was studied. N2 adsorption-desorption results showed that the mesopores with sizes of 2-20 nm in HZ5/0.3AT was formed by 0.3 M NaOH alkali treatment. The zeolite samples after modification were also characterized by XRF, AAS, XRD, SEM and NH3-TPD methods. Zn impregnated catalyst Zn/HZ5/0.3AT exhibited dramatic improvements in catalytic lifetime and liquid hydrocarbons yield. The selectivity of aromatic hydrocarbons was also improved after Zn impregnation. It is suggested that the mesopores of Zn/HZ5/0.3AT enhanced the synergetic effect of Zn species and acid sites and the capability to coke tolerance, which were confirmed by the results of catalytic test and TGA analysis, respectively.

关键词： hierarchical mesoporous ZSM-5 alkali treatment zinc impregnation methanol-to-gasoline

Effects of Chemical treatments on Thermal Expansion Properties of Cordierite Ceramics

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Journal of Wuhan University of Technology(Materials Science) 2006年第3期21卷 100-102页

作者：白佳海郭露村 School of Materials Science and Technology Nanjing University of Technology Nanjing 210009 ChinaSchool of Materials Science and Technology Shandong University of TechnologyZibo 255049China School of Materials Science and Technology Nanjing University of Technology Nanjing 210009 China

Cordierite honeycomb ceramics was treated with 1.5 M HNO3 , followed with 1.5 M NaOH at 93 ℃. The combination of acid treatment with alkali treatment significantly diminished the rebounding of coefficient of thermal expansion （CTE） caused by heat treatment, a phenomenon observed in samples treated solely with acid. Inductively coupled plasma （ICP） analysis results reveal that the alkali treatment preferentially dissolved ＂free＂ SiO2 left in the acid-treated samples, which is considered to be a key factor responsible for the CTE rebounding.

关键词： cordierite alkali treatment coefficient of thermal expansion (CTE)