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Creating mesopores in ZSM-48 zeolite by alkali treatment: Enhanced catalyst for hydroisomerization of hexadecane

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Journal of Energy Chemistry 2016年第3期25卷 539-544页

作者： Miao Zhang Lei Wang Yujing Chen Qiumin Zhang Changhai Liang Laboratory of Advanced Materials and Catalytic Engineering School of Chemical Engineering Dalian University of Technology State Key Laboratory of Fine Chemicals Institute of Coal Chemical Engineering Dalian University of Technology

ZSM-48 zeolites with various Si/Al ratios were hydrothermally synthesized in the H;N（CH;）;NH;（HDA）-containing media. The obtained samples were highly crystallized with minor mixed phases as evidenced by X-ray powder diffraction（XRD）. The alkaline treated ZSM-48 zeolites maintained its structure under different concentrations of Na OH aqueous solution. Micropores remained unchanged while mesopores with wide pore size distribution formed after the alkaline treatment. The surface area increased from 228 to 288 m;/g. The Br?nsted acid sites had little alteration while an obvious increase of Lewis acid sites was observed. The hydroisomerization of hexadecane was performed as the model reaction to test the effects of the alkali treatment. The conversion of hexadecane had almost no change, which was attributed to the preservation of the Br?nsted acid sites. While high selectivity to iso-hexadecane with an improved iso to normal ratio of alkanes was due to the mesopore formation and improved diffusivity.

关键词： ZSM-48 alkali treatment Hydroisomerization Mesopore Hexadecane

Studies on Recovery Efficiencies of Phenols from Phenol Fraction Using alkali treatment

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Journal of Chemistry and Chemical Engineering 2013年第4期7卷 334-339页

作者： S. Aruna Kumari Goruganthula Venkata Subrahmanya Sarma G. M. J. Raju J. V. S. Murty C. BhaskaraSarma Department of Chemical Engineering College of Engineering (A) Andhra University Visakhapatnam 530 003 India Department of Chemical Engineering G V P College of Engineering (A) Visakhapatnam 530 052 India Gayatri Vidya Parishad College of Engineering for Women k2sakhapatnam 530 052 India

Experiments were conducted for the extraction of phenols from the phenol fraction obtained from the coal tar distillate. The phenol fraction for the present investigation has been procured from Visakhapatnam Steel Plant, Visakhapatnam whose composition is known. The phenol fraction from coal tar distillate can be treated for extracting phenols using caustic soda. An attempt has been made to find out whether the existing practice of using only 8%-15% can be modified by increasing the strength of sodium hydroxide and also explore the possibilities of substituting the sodium hydroxide with KOH as an extractant. The different streams of liquids obtained during experimentation have been analyzed by gas chromatograph. Salient features of the study are that higher concentrations of the alkali significantly improved the separation efficiencies of phenols and also regenerate the phenolate with higher phenol content. Increase in the alkali strength has greatly improved the separation as well as the phenol content in the regenerated phenols. Disposal of effluents containing phenols may lead to environmental problem of ground water pollution and the study throws a light on the removal of phenols from the effluents to the extent possible by using higher strength alkali solutions.

关键词： alkali treatment phenol phenol fraction recovery efficiency coal tar.

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...

Effects of alkali and heat treatment on strength of porous Ti35Nb

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

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Transactions of Nonferrous Metals Society of China 2011年第6期21卷 1335-1339页

作者：万小军湖南城市学院物理与电子工程系益阳413000

Porous Ti35Nb alloy with a porosity of 66% was made by a powder metallurgical method, and then it was treated by a standard treatment for activating the surface of Ti implant materials involving alkali and heat treatment. The alkali and heat treatment causes damages of the struts of the porous Ti35Nb in the form of reaction products layer, grain-pullout and cracks. Consequently, it leads to a significant degradation of the strength of the porous alloy. The effect of the alkali and heat treatment on the strength of the porous alloy was discussed.

关键词： porous Ti-Nb alloy mechanical property alkali treatment

PREPARATION OF HOLLOW LATEX PARTICLES BY alkali-ACID treatment

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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 alkali treatments on apatite formation of microarc-oxidized coating on titanium alloy surface

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Transactions of Nonferrous Metals Society of China 2015年第4期25卷 1151-1157页

作者：赵国亮夏龙钟博吴松松宋亮温广武哈尔滨工业大学(威海)材料学院威海264209

alkali treatments with three concentrations were used to modify a microarc-oxidized(MAO) coating on titanium alloy surface in order to further improve its surface bioactivity. Morphology, chemical compositions and phase constitues, roughness, contact angle and apatite induction of the alkali-treated coatings were studied and compared. Scanning electron microscope(SEM) was applied to observe the morphologies, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) were used to detect the phase constitutes and chemical compositions, a surface topography profilometer was used to analyze the surface roughness, and contact angle was measured by liquid drop method. alkali treatements result in the formation of Na2Ti6O13 and Na2Ti3O7 phase on the MAO coating, which leads to the increase of surface roughness and the decrease of contact angle. Experimental results showed that the apatite induction of the alkali-treated coatings was dependent on the applied alkali concentrations during treatments, and Na+concentration can promote the formation of apatite phase.

关键词： titanium alloy micro-arc oxidation alkali treatment alkali concentration Ti—OH group apatite formation

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

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

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