期刊文献+
共找到96,025篇文章
< 1 2 250 >
每页显示 20 50 100
One-pot synthesis of bimetallic CeCu-SAPO-34 for high-efficiency selective catalytic reduction of nitrogen oxides with NH_(3) at low temperature
1
作者 Shuang Qiu Yonghou Xiao +3 位作者 Haoran Wu Shengnan Lu Qidong Zhao Gaohong He 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第4期193-202,共10页
NH_(3) selective catalytic reduction(SCR) has been widely recognized as a promising technique for reducing nitrogen oxides from diesel vehicle exhausts. High-efficiency SCR catalysts that could perform at low temperat... NH_(3) selective catalytic reduction(SCR) has been widely recognized as a promising technique for reducing nitrogen oxides from diesel vehicle exhausts. High-efficiency SCR catalysts that could perform at low temperatures are essential to denitration. In this work, a series of bimetallic CeCu-SAPO-34 molecular sieves were synthesized by one-step hydrothermal method. The Ce Cu-SAPO-34 maintained good crystallinity and a regular hexahedron appearance of Cu-SAPO-34 after introducing Ce species, while exhibiting a higher specific surface area and pore volume. The as-prepared CeCu-SAPO-34 with 0.02%(mass) Ce constituent exhibited the best catalytic activity below 300℃ and a maximum NO_(x) conversion of 99% was attained;the NO_(x) removal rates of more than 68% and 94% were achieved at 150℃ and 200℃, respectively. And the introduction of cerium species in Cu-SAPO-34 improves the low-temperature hydrothermal stability of the catalyst towards NH_(3)-SCR reaction. Additionally, the introduced Ce species could enhance the formation of abundant weak Br?nsted acid centers and promote the synergistic effect between CuO grains and isolated Cu^(2+) to enhance the redox cycle, which benefit the NH_(3)-SCR reaction.This work provides a facile synthesis method of high-efficiency SCR denitration catalysts towards diesel vehicles exhaust treatment under low temperature. 展开更多
关键词 CeCu-SAPO-34 Selective catalytic reduction(SCR) Low temperature DeNO_(x) one-pot synthesis
下载PDF
One-pot synthesis and characterization of a new, branched polycarbosilane bearing allyl groups 被引量:9
2
作者 Tian Hua Huang Zhao Ju Yu +4 位作者 Xu Min He Mu He Huang Li Fu Chen Hai Ping Xia Li Tong Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第6期754-757,共4页
A highly branched polycarbosilane bearing allyl groups has been prepared by a one-pot synthesis with chloromethyltrichlorosilane, chloromethylmethyldichlorosilane and allyl chloride as the starting materials. The resu... A highly branched polycarbosilane bearing allyl groups has been prepared by a one-pot synthesis with chloromethyltrichlorosilane, chloromethylmethyldichlorosilane and allyl chloride as the starting materials. The resultant polymer, with the approximate formula [SiH1.2(CH3)0.71(CH2CHCH2)0.09CH2]n, has been characterized by 1H, 13C, and 29Si NMR, GPC, TG and elemental analysis. It could be cross-linked thermally at 170 °C in the absence of oxygen. Pyrolysis of the polymer gave a ceramic with a yield of about 70%. 展开更多
关键词 POLYCARBOSILANE one-pot synthesis Silicon carbide precursor Ceramic precursor
下载PDF
One-pot synthesis of 2-aminothiazoles in PEG-400 被引量:8
3
作者 Dhanaji V.Jawale Dinesh L.Lingampalle +1 位作者 Umesh R.Pratap Ramrao A.Mane 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第4期412-416,共5页
A facile one-pot synthesis of 2-aminothiazoles has been carried in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric a-bromoketones as well as the volatile,toxic organic solvents.
关键词 one-pot synthesis 2-Aminothiazoles Polyethylene glycol-400 N-BROMOSUCCINIMIDE
下载PDF
Efficient one-pot synthesis of 1,3-diaryl-3H-benzo[f]chromenes using ferric hydrogensulfate 被引量:4
4
作者 Hossein Eshghi Gholam Hossein Zohuri +1 位作者 Saman Damavandi Mohammad Vakili 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第12期1423-1426,共4页
An efficient and easy method for one-pot three-component synthesis of l,3-disubstituted-3H-benzo[f]chromenes by the condensation of naphtol,aromatic aldehyde derivatives and phenylacetylene in the presence of ferric h... An efficient and easy method for one-pot three-component synthesis of l,3-disubstituted-3H-benzo[f]chromenes by the condensation of naphtol,aromatic aldehyde derivatives and phenylacetylene in the presence of ferric hydrogensulfate[Fe(HSO4)3], has been described.The catalyst displayed high activity which afforded the corresponding 1,3-disubstituted-3H-benzo[f]chromenes in satisfying yields.Alkyl-substituted phenols were examined and the corresponding benzopyran derivatives were synthesized in moderate yields.Heterogeneous nature of the using catalyst made it reusable for further chemical reactions. 展开更多
关键词 1 3-Disubstituted-3H-benzo[f]chromenes Ferric hydrogensulfate one-pot synthesis Naphtopyran BENZOPYRAN
下载PDF
One-pot Synthesis of Lewis Acidic Ionic Liquids for Friedel-Crafts Alkylation 被引量:3
5
作者 Ling HE Guo Hong TAO Wei Shan LIU Wei XIONG Tao WANG Yuan KOU 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第3期321-324,共4页
Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. ... Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. The ionic liquids were used as catalyst for Friedel-Crafts alkylation of benzene and 1-dodecene. The turnovers of l-dodecene were higher than 99%. Monoalkylbenzene selectivity was 98%, while the 2-substituent product selectivity was 45%. 展开更多
关键词 Ionic liquids green chemistry one-pot synthesis Lewis acidity alkylation.
下载PDF
A bifunctional and recyclable catalyst:Amine and ionic liquid grafting on MOFs for the one-pot synthesis of N-aryl oxazolidin-2-ones 被引量:3
6
作者 Siying Chong Tongtong Wang +4 位作者 Haijun Zhong Lingfei Xu Hailong Xu Zhongwu Lv Min Ji 《Green Energy & Environment》 SCIE CSCD 2020年第2期154-165,共12页
A bifunctional heterogeneous catalyst was designed and synthesized,denoted DMEDA/IL–NH2-MIL-101.The structure and physical-chemical characterization of DMEDA/IL–NH2-MIL-101 and its precursors were characterized by S... A bifunctional heterogeneous catalyst was designed and synthesized,denoted DMEDA/IL–NH2-MIL-101.The structure and physical-chemical characterization of DMEDA/IL–NH2-MIL-101 and its precursors were characterized by SEM,N2 adsorption-desorption,XPS,FT-IR,PXRD,elemental analysis,and TGA techniques.The date showed that the two catalytic components of N,N-dimethylethylenediamine(DMEDA)and 1-butyl-3-methylimidazolium bromide(BmimBr)were chemically immobilized in NH2-MIL-101 nanocages.The amine of DMEDA was grafted onto carrier NH2-MIL-101 by N–Cr coordinate covalent bonds and the ionic liquid of BmimBr(IL(Br-))was anchored in the NH2-MIL-101 nanocages by'ship-in-a-bottle'method,in which the amidogen of NH2-MIL-101 condensed with N,N-carbonyldiimidazole(CDI)firstly,and then alkylated with 1-bromo butane.This novel heterogeneous catalyst with two different active sites can efficiently catalyze the synthesis of N-aryl oxazolidin-2-ones from carbon dioxide(CO2),epoxides,and anilines in one-pot under mild solvent-free conditions.It not only showed good stability and recoverability after five cycles but also exhibited shape selectivity for the substrate due to the synergic catalysis of amine,ionic liquid,and NH2-MIL-101.This novel bifunctional material is a promising solid catalyst for the green synthesis of N-aryl oxazolidin-2-ones. 展开更多
关键词 Metal-organic frameworks Ionic liquid immobilization N-aryl oxazolidin-2-ones one-pot synthesis Bifunctional heterogeneous catalyst
下载PDF
One-pot synthesis of network supported catalyst using supramolecular gel as template 被引量:2
7
作者 Yong Liang Li Ming Tang Yu Xia Kai Chen Bo Tian Li Xin Jin 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第8期991-994,共4页
A simple and general strategy is described for preparing network supported catalyst through a one-pot synthetic procedure using supramolecular gel as template.This procedure directly attaches ligand to support during ... A simple and general strategy is described for preparing network supported catalyst through a one-pot synthetic procedure using supramolecular gel as template.This procedure directly attaches ligand to support during fabricating the support.Using this strategy,supported CuBr/di-(2-picolyl) amine catalyst with U-shaped fibrillar network was prepared and used in atom transfer radical polymerization of methyl methacrylate.XPS and SEM characterization of the catalyst revealed homogeneous distribution of ligand,sufficient reactive sites,adequate mechanical strength and macroporosity.The polymerization results demonstrated high activity and reusability of such catalyst.This strategy might be extended to other supported catalysts used in column reactors. 展开更多
关键词 one-pot synthesis Network supported catalyst Supramolecular gel Atom transfer radical polymerization
下载PDF
Strontium chloride-catalyzed one-pot synthesis of 4(3H)-quinazolinones under solvent-free conditions 被引量:2
8
作者 Min Wang Zhi Guo Song Ting Ting Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第10期1167-1170,共4页
Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid, ortho esters and amines leading to the formation of 4(3H)-quinazolinone derivatives in good yields at ... Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid, ortho esters and amines leading to the formation of 4(3H)-quinazolinone derivatives in good yields at room temperature under solvent-free conditions. 展开更多
关键词 4(3H)-Quinazolinones one-pot synthesis Solvent-free conditions Strontium chloride
下载PDF
One-pot Synthesis of 2,5-Disubstituted Oxazoles Using Poly[styrene(iodosodiacetate)] 被引量:1
9
作者 JiangMinCHEN LuLingWU XianHUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第2期143-144,共2页
关键词 Poly[styrene(iodosodiacetate)] one-pot synthesis 2 5-disubstituted oxazoles.
下载PDF
Solar thermochemical reactionsⅢ:A convenient one-pot synthesis of 1,2,4,5-tetrasubstituted imidazoles catalyzed by high surface area SiO_2 and induced by solar thermal energy 被引量:1
10
作者 Ramadan A.Mekheimer Afaf M.Abdel Hameed +1 位作者 Seham A.A.Mansour Kamal Usef Sadek 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第7期812-814,共3页
A simple, convenient and efficient method for the synthesis of 1,2,4,5-tetrasubstituted imidazole derivatives using benzoin, an aromatic aldehyde, an aromatic amine in the presence of ammonium acetate catalyzed by hig... A simple, convenient and efficient method for the synthesis of 1,2,4,5-tetrasubstituted imidazole derivatives using benzoin, an aromatic aldehyde, an aromatic amine in the presence of ammonium acetate catalyzed by high surface area SiO2 and induced by free solar thermal energy was reported. C 2009 Kamal User Sadek. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. 展开更多
关键词 one-pot synthesis SiO2 Solar thermal energy Tetrasubstituted imidazole
下载PDF
A facile one-pot synthesis of new thieno-[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives 被引量:1
11
作者 A.Davoodnia H.Behmadi +2 位作者 A.Zare Bidaki M.Bakavoli N.Tavakoli Hoseini 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第10期1163-1165,共3页
A facile one-pot synthesis of new 3-arylthieno[2,3-d]pyrimidine-2,4(1H,3H)-diones via base-catalyzed cyclocondensation of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with aryl isocyanates is described.
关键词 3-Arylthieno[2 3-d]pyrimidine-2 4(1H 3H)-diones Aryl isocaynates Base-catalyzed cyclocondensation one-pot synthesis
下载PDF
One-pot Synthesis and Crystal Structure of (1S,2R,3S,4R,5S)-1-Phenyl-2,4-dibenzoyl-3,5-difurylhexanol
12
作者 CHEN Xiang-Ming YIN Ye-Gao CHEN He-Ru DING Jun 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第6期699-703,共5页
(1S,2R,3S,4R,5S)-1-Phenyl-2,4-dibenzoyl-3,5-difurylhexanol 1 was synthesized by one-pot reaction of hypnone and furfurol in alkali H2O/EtOH solution and structurally defined to contain a chair-formed aliphatic carbo... (1S,2R,3S,4R,5S)-1-Phenyl-2,4-dibenzoyl-3,5-difurylhexanol 1 was synthesized by one-pot reaction of hypnone and furfurol in alkali H2O/EtOH solution and structurally defined to contain a chair-formed aliphatic carbocycle, on which the bulky substituents occupy the equatorial positions. 展开更多
关键词 substituted cyclohexanol one-pot synthesis crystal structure hydrogen bond
下载PDF
One-pot Synthesis and X-ray Structure Determination of 7-(Diethylamino)-3-(4-aminophenyl)coumarin
13
作者 KULAI Ihor MALLET-LADEIRA Sonia +1 位作者 KOVTUNENKO Volodymyr VOITENKO Zoia 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第12期1841-1844,共4页
7-(Diethylamino)-3-(4-aminophenyl)coumarin has been synthesized in a new one-pot synthesis by a three-step process starting from 4-(diethylamino)salicylaldehyde and 4-nitrophenylacetonitrile. The product was obt... 7-(Diethylamino)-3-(4-aminophenyl)coumarin has been synthesized in a new one-pot synthesis by a three-step process starting from 4-(diethylamino)salicylaldehyde and 4-nitrophenylacetonitrile. The product was obtained in a good yield with a high degree of purity and characterized by NMR, IR and HR-MS. The orange crystals of the title compound were grown from ethyl acetate solution. The solid state structure was established by X-ray crystallography analysis. The crystal belongs to the orthorombic system, space group Pccn with a = 11.1095(5), b = 33.0187(15), c = 17.2865(7) A, V= 6341.1(5) A3, C19H20N2O2, Mr = 308.37, ρcalc = 1.292 g·cm^-3, = 0.085 mm^-1, F(000) = 2624, the final R = 0.0480 and wR = 0.1265 (I〉 2σ(I)). 展开更多
关键词 COUMARIN DYE crystal structure FLUORESCENCE one-pot synthesis
下载PDF
One-pot Synthesis of Bio-inspired Layered Materials of 3D Graphene Network/Calcium Carbonate
14
作者 张晶 YAO Bin +7 位作者 PING Hang YU Hongjian ZHANG Fan ZHANG Jinyong WANG Yucheng WANG Hao WANG Weimin 傅正义 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第4期795-799,共5页
A bio-inspired layered material of reduced graphene oxide(RGOs) and calcium carbonate was synthesized via a one-pot strategy in DMF/H2O mixed solvent. The experimental results show that the product is a layered mate... A bio-inspired layered material of reduced graphene oxide(RGOs) and calcium carbonate was synthesized via a one-pot strategy in DMF/H2O mixed solvent. The experimental results show that the product is a layered material of wrinkled RGOs networks and micron-sized calcium carbonate particles with uniform granular diameter and homogeneous morphology, which are distributed between the layered gallery of the graphene scaffold. The polymorph and the morphology of the in-situ produced calcium carbonate particles can be manipulated by simply changing the temperature scheme. Besides, the graphene oxide was reduced to a certain extent, and the hierarchical wrinkles were generated in the RGOs layer by the in-situ formation of the calcium carbonate particles. This work provides a facile and controllable strategy for synthesizing layered material of RGOs and carbonates, and also presents a platform for making three-dimensional porous wrinkled RGOs networks. 展开更多
关键词 bio-inspired layered structure one-pot synthesis graphene calcium carbonate
下载PDF
A New One-Pot Synthesis of Macroheterocycles Using Mannich Reaction
15
作者 Min Min YANG Jin Qi ZHANG Zhen SHEN (Department of Chemistry, Nanjing University, Nanjing 210093) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第10期845-846,共2页
Three N,N-heterylmethyl derivates of diaza-18-crown-6(I) are readily prepared by the reaction of (I) with paraformaldehyde and heterocyclic compounds in dry benzene.
关键词 A New one-pot synthesis of Macroheterocycles Using Mannich Reaction
下载PDF
Crystal Structures of Two Compounds from a Rapid and One-pot Synthesis Method
16
作者 周宝晗 徐保明 +3 位作者 严伯承 马丽 陈坤 华云涛 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第3期409-415,共7页
Compounds 1 (C17H22N2,Mr =254.37) and 2 (C13H16N2,Mr=200.28) have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction.Crystal 1 belongs to triclinic,space group P(1)... Compounds 1 (C17H22N2,Mr =254.37) and 2 (C13H16N2,Mr=200.28) have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction.Crystal 1 belongs to triclinic,space group P(1) with a =6.524(2),b =8.987(3),c =12.746(5) A,α =95.220(7),β =90.055(6),γ =104.431(6)°,V =720.5(4) A^3,Z =2,Dc =1.173 g/cm^3,μ(MoKα) =0.069 mm1,F(000) =276,R =0.0578 and wR =0.1221 for 1487 observed reflections Ⅰ 〉 2o(Ⅰ).Crystal 2 is of tetragonal system,space group Ⅰ41/a with a =20.763(10),b =20.763(10),c =11.427(6) A,V=4926(4) A3,Z =16,Dc =1.080 g/cm^3,μ(MoKα) =0.065 mm-1,F(000) =1728,R =0.0581 and wR =0.1288 for 1408 observed reflections with Ⅰ 〉 2σ(Ⅰ).Although the two compounds are similar with the same pyrazole and benzene ring units,X-ray analysis reveals that their structures are completely different maybe caused by steric effects. 展开更多
关键词 pyrazole crystal structures one-pot synthesis steric effects
下载PDF
Efficient one-pot synthesis of n-butyl levulinate from carbohydrates catalyzed by Fe_2(SO_4)_3 被引量:8
17
作者 Ran An Guizhuan Xu +2 位作者 Chun Chang Jing Bai Shuqi Fang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第3期556-563,共8页
Butyl levulinate(BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the cat... Butyl levulinate(BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe(SO)was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose, inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe(SO), showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe(SO)was studied by characterizing them using powder X-ray diffraction(XRD), scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS). A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass. 展开更多
关键词 one-pot n-butyl levulinate Metal sulfate Carbohydrates
下载PDF
One-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles under ultrasonic irradiation 被引量:1
18
作者 Ying Jun Li Ya Zhen Sun +4 位作者 Yong Ting Xu Kun Jin Li Ping Wen Ni Bo Hou Xiao Xiao Sun 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第9期1047-1048,共2页
A facile one-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles was achieved by ultrasonic irradiation of a mixture of 1-naphthylacetyl chloride, NH4CNS, CH2Cl2 and PEG-400 for 1.5 h at 10–20 °C and subsequen... A facile one-pot synthesis of 2,5-disubstituted-1,3,4-thiadiazoles was achieved by ultrasonic irradiation of a mixture of 1-naphthylacetyl chloride, NH4CNS, CH2Cl2 and PEG-400 for 1.5 h at 10–20 °C and subsequent irradiation for 1.5 h in the presence of N-arylglycine hydrazides. This method requires short time and gives thiadiazoles in high yields. 展开更多
关键词 one-pot Ultrasonic irradiation 2 5-Disubstituted-1 3 4-thiadiazoles synthesis
下载PDF
Improved One-pot Synthesis of 4,6-Dihydroxyisophthalic Acid and 2,3-Dihydroxyterephthalic Acid 被引量:3
19
作者 Guang Dong LEI Li Xin LI +1 位作者 Zhi Yun LU Ming Gui XIE 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第8期1039-1042,共4页
An improved method for the large-scale preparation of 4,6-dihydroxyisophthalic acid and 2,3-dihydroxyterephthalic acid has been developed.Compared to the previous procedures,this new process-requires much lower CO2 pr... An improved method for the large-scale preparation of 4,6-dihydroxyisophthalic acid and 2,3-dihydroxyterephthalic acid has been developed.Compared to the previous procedures,this new process-requires much lower CO2 pressure of 0.3 Mpa and shorter reaction time.thus providing a convenient access for large-scale synthesis.The yield is high (93% and 65%,respectively), and the oxidation of phenol is nearly inhibited,neither decolorization nor further chromatographic purification is required. 展开更多
关键词 one-pot LARGE-SCALE 4 6-dihydroxyisophthalic acid 2 3-dihydroxyterephthalic acid.
下载PDF
One-Pot Synthesis of Hierarchically Nanoporous SSZ-13 for Conversion of Methanol to Olefins 被引量:2
20
作者 Li Yuping Wang Yanyue +3 位作者 Zhang Yi Liu Rui Li Xiaofeng Dou Tao 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2017年第3期68-76,共9页
The main disadvantage of microporous SSZ-13 catalyst used in the methanol to olefins(MTO) process is its rapid deactivation due to its relatively low coke resistance. Meanwhile, the hierarchical zeolites usually exhib... The main disadvantage of microporous SSZ-13 catalyst used in the methanol to olefins(MTO) process is its rapid deactivation due to its relatively low coke resistance. Meanwhile, the hierarchical zeolites usually exhibit improved catalytic stability thanks to their better mass transfer ability. Herein, the hierarchically nanoporous SSZ-13 zeolites were one-pot synthesized by using N,N,N-trimethyl-1-adamantanammonium hydroxide as a microporous structure directing agent and C_(18)H_(37) N^+(CH_3)_2 C_6H_(12) N^+(CH_3)_2 C_6 H_(13)(Br^-)_2(hereinafter abbreviated as C_(18-6-6) Br_2) as a mesoporogen. The hierarchically nanoporous SSZ-13 catalyst was characterized by XRD, N_2 physisorption, SEM, TEM, TG-DTG, ^(27) Al and ^(29) SiNMR spectroscopy and NH_3-TPD techniques. The results showed that the hierarchical SSZ-13 zeolite synthesized in the presence of the C_(18-6-6) Br_2 surfactant exhibits aggregates of primary nanocrystals and contains the well-developed mesopores and excellent acidity. Compared to its conventional counterpart, the hierarchical SSZ-13 zeolite has longer catalytic lifetime and higher selectivity for ethylene and propylene in the MTO reaction, which can be attributed to the synergistic effect of their good acidity and improved diffusion properties resulted from the hierarchical pore structure. 展开更多
关键词 hierarchical zeolites SSZ-13 TEMPLATE synthesis MESOPORE methanol-to-olefins
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部