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油分散性核壳Fe3O4@MnO纳米复合材料的合成及其对氧化环化反应的催化性能(英文) 被引量:1
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作者 杨清香 雷李玲 +5 位作者 王青青 王芳草 王聪 董梦果 李银萍 陈志军 《无机化学学报》 SCIE CAS CSCD 北大核心 2020年第2期385-391,共7页
采用两相种子介导法以锰油酸为前驱体制备了一种新型油溶性核壳结构Fe3O4@MnO纳米复合材料,直径约为15 nm。所制备的具有核壳结构的纳米复合材料是单分散且均匀的。该产物对2-羟基苯乙酮和1,2-二氨基苯的氧化环化反应表现出高且可循环... 采用两相种子介导法以锰油酸为前驱体制备了一种新型油溶性核壳结构Fe3O4@MnO纳米复合材料,直径约为15 nm。所制备的具有核壳结构的纳米复合材料是单分散且均匀的。该产物对2-羟基苯乙酮和1,2-二氨基苯的氧化环化反应表现出高且可循环的催化活性。与在环化反应中使用的其他报道的催化剂相比,所制备的Fe3O4@MnO纳米复合材料绿色、廉价且更适合于大规模工业应用。 展开更多
关键词 Fe3O4@MnO 纳米复合材料 磁性材料 油分散性 氧化环化反应 催化
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吲哚环化合物合成方法的进展 被引量:22
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作者 石雷 王新平 蔡天锡 《有机化学》 SCIE CAS CSCD 北大核心 2001年第3期200-204,共5页
综述了在工业。
关键词 吲哚环化合物 反应机理 合成方法 移位重排 新核环化反应 亲电环化反应 还原环化反应 氧化环化反应
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Recent advances in metal-free catalysts for the synthesis of cyclic carbonates from CO_2 and epoxides 被引量:16
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作者 兰东辉 樊娜 +5 位作者 王莹 高显 张平 陈浪 区泽堂 尹双凤 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第6期826-845,共20页
The aim of "green chemistry" and "atom economy" is to utilize carbon dioxide and replace harmful reactants such as CO and phosgene for the production of cyclic carbonates. In this paper, metal-free catalysts inclu... The aim of "green chemistry" and "atom economy" is to utilize carbon dioxide and replace harmful reactants such as CO and phosgene for the production of cyclic carbonates. In this paper, metal-free catalysts including organic bases, ionic liquids, supported catalysts, organic copolymers and carbon materials for the synthesis of cyclic carbonates by the cycloaddition of carbon dioxide to epoxides are reviewed. Recent advances in the design of the catalysts and the understanding of the reaction mechanism are summarized and discussed. The synergistic effects of organic bases and hydrogen bond donors, organic bases and nucleophilic anions, hydrogen bond donors and nucleophilic anions and active components and supports are highlighted. The challenge is to develop metal-free catalysts suitable for carbon dioxide capture and fixation. The ultimate goal is to synthesize cyclic carbonates in a flow reactor directly using carbon dioxide from industrial flue gas at ambient temperature and atmospheric pressure. By using synergetic effects, a multi-functional approach can meet the design strategy of metal-free catalysts for carbon dioxide adsorption and activation as well as epoxide ring opening. 展开更多
关键词 CYCLOADDITION Carbon dioxide EPOXIDE Cyclic carbonate Metal-free catalyst SYNERGY
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Synthesis of cyclic carbonates from epoxides and CO_2 in acetonitrile via the synergistic action of BMIMBr and electrogenerated magnesium 被引量:2
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作者 钮东方 吴志娟 +3 位作者 张历朴 杜荣斌 徐衡 张新胜 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第7期1076-1080,共5页
Using 1-butyl-3-methyl-imidazolium bromide (BM1MBr) as the supporting electrolyte and magne- sium as the sacrificial anode, a new and highly efficient electrochemically catalytic route was devel- oped for the synthe... Using 1-butyl-3-methyl-imidazolium bromide (BM1MBr) as the supporting electrolyte and magne- sium as the sacrificial anode, a new and highly efficient electrochemically catalytic route was devel- oped for the synthesis of cyclic carbonates from epoxides and CO2. Based on the cooperative action of BMIMBr and an electrogenerated magnesium salt obtained under a N2 atmosphere, CO2 reacted with a wide range of epoxides to readily generate cyclic carbonates in moderate to excellent yields under mild conditions. 展开更多
关键词 Electrogenerated magnesium saltlmidazolium bromideCarbon dioxideEpoxideCarboxylationCyclic carbonate
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2-噁唑烷酮及其衍生物的应用与合成
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作者 王莉 张晓阳 《甘肃化工》 2004年第2期28-30,共3页
介绍2-噁唑烷酮的应用及几种不同的合成方法,并加以简单比较。同时介绍2-噁唑烷酮五类衍生物的应用及先进的合成方法。
关键词 合成 电解环化氧化反应 2-噁唑烷酮衍生物 4-烷氧基羰基-2-噁唑烷酮类 5-羟甲基-2-噁唑烷酮类 2-噁唑烷酮含硝基咪唑类 5-苯乙基-2-噁唑烷酮类 N-乙烯基-2-噁唑烷酮类
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A “Green” Cyclohexanone Oxidation Route Catalyzed by Hollow Titanium Silicate Zeolite for Preparing ε-Caprolactone,6-Hydroxyhexanoic Acid and Adipic Acid 被引量:5
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作者 Xia Changjiu Zhu Bin +1 位作者 Lin Min Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期33-41,共9页
Hollow titanium silicalite (HTS) molecular sieve has been synthesized, and information on its structure, physico- chemical characterization, as well as surface property was investigated by a host of analytical metho... Hollow titanium silicalite (HTS) molecular sieve has been synthesized, and information on its structure, physico- chemical characterization, as well as surface property was investigated by a host of analytical methods, such as XRF, XRD, low-temperature N2 adsorption/desorption, TEM, FT-IR, UV-Vis, 29Si MAS NIVIR, and XPS techniques. The characterization results suggest that HTS zeolite has a special hollow crystal structure and its mesopore volume is larger than that of TS-1 zeolite. The titanium species in this zeolite are composed of the framework tetrahedral Ti (IV) ions and extra-framework octahedral Ti (IV) ions, which tend to disperse into its bulk phase. This zeolite material also has been applied to catalyze the cyclohexanone oxidation process, and the products are not completely consistent with those results obtained by using TS-1 zeolite, which might be caused by their difference in pore structure and pore volume, especially the mesopore volume. Cy- clohexanone oxidation catalyzed by HTS zeolite is a representative consecutive reaction, the main target products of which are e-caprolactone, 6-hydroxyhexanoic acid and adipic acid. The effect of H202/cyclohexanone mole ratio on the cyclohexa- none conversion, the total target product selectivity, the distribution of three target products selectivity and their variations along with reaction time is also researched and analyzed, which indicate that HTS zeolite shows a high performance for the Baeyer-Villiger reaction of cyclohexanone and catalytic oxidation of 6-hydroxyhexanoic acid under mild conditions, and the quantity of active surface titanium species as well as the pore structure and mesopore volume controlling the mass diffusion rate are the key factors determining the catalytic activity of HTS zeolite and product selectivity. 展开更多
关键词 catalytic oxidation CYCLOHEXANONE HTS zeolite Baeyer-Villiger reaction consecutive reaction
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Cobalt carbonyl ionic liquids based on the 1,1,3,3-tetra-alkylguanidine cation:Novel, highly efficient, and reusable catalysts for the carbonylation of epoxides 被引量:2
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作者 Wei Zhang Feng Han +2 位作者 Jin Tong Chungu Xia Jianhua Liu 《Chinese Journal of Catalysis》 EI CSCD 北大核心 2017年第5期805-812,共8页
A series of novel cobalt carbonyl ionic liquids based on1,1,3,3‐tetra‐alkyl‐guanidine,such as[1,1‐dimethyl‐3,3‐diethylguanidinium][Co(CO)4](3a),[1,1‐dimethyl‐3,3‐dibutylguanidinium][Co(CO)4](3b),[1,1‐dimethy... A series of novel cobalt carbonyl ionic liquids based on1,1,3,3‐tetra‐alkyl‐guanidine,such as[1,1‐dimethyl‐3,3‐diethylguanidinium][Co(CO)4](3a),[1,1‐dimethyl‐3,3‐dibutylguanidinium][Co(CO)4](3b),[1,1‐dimethyl‐3,3‐tetramethyleneguanidinium][Co(CO)4](3c),and[1,1‐dimethyl‐3,3‐pentamethyleneguanidinium][Co(CO)4](3d),were synthesized in good yields and were also characterized using infrared spectroscopy,ultraviolet‐visible spectroscopy,1H nuclear magnetic resonance(NMR)spectroscopy,13C NMR spectroscopy,high‐resolution mass spectrometry,differential scanning calorimetry,and thermogravimetric analysis.The four compounds exhibited high thermal and chemical stability.In addition,the catalytic performance of these compounds was investigated in the carbonylation of epoxides,with3a exhibiting the best catalytic activity without the aid of a base as the additive.The catalyst could be reused at least six times without significant decreases of the selectivity or conversion rate.Moreover,the catalyst system exhibited good tolerance with terminal epoxides bearing alkyl,alkenyl,aryl,alkoxy,and chloromethyl functional groups. 展开更多
关键词 Cobalt carbonyl ionic liquid CARBONYLATION EPOXIDE Tetra‐alkylguanidine RECYCLABILITY
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Recovery and Recycling of Ti Supported Bimodal Mesoporous Catalysts Prepared via Ship-in-a-bottle Method in the Epoxidation of Cyclohexene
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作者 白诗扬 胡新涛 +2 位作者 孙继红 任博 王金鹏 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第8期914-920,共7页
Ti/BMMs (Ti supported bimodal mesoporous silica) catalysts have been prepared via self-assembly route com- bined with ship-in-a-bottle method. The recovery and recycling performances of Ti/BMMs were investigated in ... Ti/BMMs (Ti supported bimodal mesoporous silica) catalysts have been prepared via self-assembly route com- bined with ship-in-a-bottle method. The recovery and recycling performances of Ti/BMMs were investigated in the epoxidation of cyclohexene. In order to the evaluate the regeneration methods and to examine the deactivation behaviors, the deactivated Ti/BMMs catalysts were washed in chloroform or calcinated at 450 ℃ for 6 h and then activity of the recovery catalysts were examined. Meanwhile, the structure features and surface properties of the regenerated catalysts were characterized by X-ray diffraction, N2-sorption analysis, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravi- metric analysis, UV visible spectroscopy and X-ray photoelectron spectroscopy. The results showed that the typical bimodal mesoporous structure of recycled Ti/BMMs catalysts was still maintained, and the phenomenon of Ti leaching during the catalytic process and recovery was negligible. In particular, spectroscopic observations indicated that the effects of the regeneration methods on the tetrahedrally-coordinated Ti species and catalytic deactivation were remarkable. The main reasons were related to the polarities of used solvents during recovery tests, the environment medium of adsorbed water inside mesopore channels and the deposition of bulky mole- cules of by-products on the mesoporous surface. 展开更多
关键词 Ti/BMMs Ship-in-a-bottle method RECOVERY RECYCLING Epoxidation of cyclohexene
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Spontaneous combustion tendency of fresh and pre-oxidized sulfide ores 被引量:2
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作者 阳富强 吴超 李孜军 《Journal of Central South University》 SCIE EI CAS 2014年第2期715-719,共5页
Three representative sulfide ore samples were collected from typical metal mines,and their corresponding pre-oxidized products were obtained under nature environment.The thermal behaviors of each sample at heating rat... Three representative sulfide ore samples were collected from typical metal mines,and their corresponding pre-oxidized products were obtained under nature environment.The thermal behaviors of each sample at heating rates of 5,10,15 and 20 °C/min in air flow from ambient temperature to 800 °C were studied by simultaneous thermal analysis and the TG/DSC curves before and after the pre-oxidation were compared.By the peak temperature of DTG curves,the whole reaction process for each sample was divided into different stages,and the apparent activation energies were calculated by the Ozawa-Flynn-Wall method.The results show that the reaction process of each sample after pre-oxidation is more complex,with quicker reaction rates,fewer heat production quantities,and higher or lower ignition-points.The apparent activation energies decrease from 364.017-474.228 kJ/mol to 244.523- 333.161 kJ/mol.Therefore,sulfide ores are more susceptible to spontaneous combustion after the pre-oxidation. 展开更多
关键词 sulfide ores spontaneous combustion tendency apparent activation energy PRE-OXIDATION
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Silver-catalyzed carboxylative cyclization of alkynic hydrazones with carbon dioxide
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作者 Wenzhen Zhang Yuqian Sun +2 位作者 Min Zhang Hui Zhou Xiaobing Lu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第8期1153-1159,共7页
The development of new catalytic methodologies to synthesize heterocyclic fine chemicals using carbon dioxide as a synthon has attracted considerable attention. Herein, we report the silver( I)-catalyzed carboxylative... The development of new catalytic methodologies to synthesize heterocyclic fine chemicals using carbon dioxide as a synthon has attracted considerable attention. Herein, we report the silver( I)-catalyzed carboxylative cyclization of a variety of alkynic hydrazones with carbon dioxide to produce the corresponding 1,3,4-oxadiazin-2-ones under mild reaction conditions. In this reaction, silver(I) salts play a π-Lewis acid role for the highly efficient activation of the alkyne moiety in the hydrazone substrates. Single-crystal X-ray analysis and NOE experiments confirm that the newly formed oxadiazinone products exhibit Z configuration. Based on control experiments and NMR studies, a mechanism including the formation of a reactive carbazate intermediate, electrophilic cyclization, and subsequent protonation is proposed. This study offers an efficient and atom- economical method for the synthesis of biologically important 1,3,4-oxadiazin-2-ones. 展开更多
关键词 Carbon dioxide Silver catalysis Carboxylative cyclization Alkynic hydrazine Oxadiazinone Homogeneous catalysis
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Macrokinetics of Ethylene Epoxidation over A-type Silver Catalyst
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作者 Liang Rujun Li Jianwei 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第3期44-52,共9页
By taking the surface chemical reactions as the rate-controlling step, a possible reaction mechanism for ethylene epoxidation to synthesize ethylene oxide over the A-type silver catalyst was developed, while it was as... By taking the surface chemical reactions as the rate-controlling step, a possible reaction mechanism for ethylene epoxidation to synthesize ethylene oxide over the A-type silver catalyst was developed, while it was assumed that the epoxidation reaction would take place between ethylene and the un-dissociated adsorbed oxygen O2 a on the solo active sites, while the deep oxidation would occur between ethylene and the dissociated adsorbed oxygen Oa on the adjacent multi-active sites. In order to describe the effect of 1,2-C2H4Cl2(EDC) inhibitor on the ethylene epoxidation process, the reversible reactions between EDC and vinyl chloride(VC) on the active sites of silver catalyst was introduced. According to the assumed mechanism, the hyperbolic macro-kinetic model of ethylene epoxidation over the A-type silver catalyst was established, and the macrokinetic experiments were carried out in an internal-recycle gradientless reactor operating at a pressure of 2.1 MPa and a temperature in the range of 217.8—249.0 ℃, with the gas composition(molar fraction) consisting of 15.82%—34.65% C2H4, 2.55%—7.80% O2, 0.88%—6.15% CO2, 0.15—2.61 μmol/mol of 1,2-C2H4Cl2 and 0.14—1.28 μmol/mol of C2H3 Cl. By means of the Simplex Optimal Method, the parameters of the macrokinetic models were estimated. Statistical test showed that the macrokinetic models developed for the A-type silver catalyst agree well with the experimental results. 展开更多
关键词 silver catalyst ethylene epoxidation reaction mechanism MACROKINETICS
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Studies of Cyclohexane Catalytic Oxidation Processes over Titanium Silicate-1 Zeolite
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作者 ChengShibiao WuWei SunBin MinEnze 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2003年第4期51-56,共6页
The catalytic oxidation processes for cyclohexane/H_2O_2/acetone system overthe TS-1 zeolite was studied. Study results have revealed that the cyclohexane conversion was 27%after the reaction proceeded at 100℃ for 2 ... The catalytic oxidation processes for cyclohexane/H_2O_2/acetone system overthe TS-1 zeolite was studied. Study results have revealed that the cyclohexane conversion was 27%after the reaction proceeded at 100℃ for 2 hours at a cyclohexane/H_2O_2 molar ratio of 0.8. Thecyclohexanol/cyclohexanone molar ratio was 1.3 along with a certain amount of organic acids andesters, the formation of which was closely associated with the oxidation of reaction solvent anddeep oxidation of cyclohexanone and cyclohexanol contained in the reaction products. With respect tothe catalytic oxidation of cyclohexane/H_2O_2 system the selection of appropriate solvent wascritically important. 展开更多
关键词 CYCLOHEXANE TS-1 zeolite catalytic oxidation
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Kinetics of 2-Methylbutene-2 Epoxidation with 2-Methylbutane Hydroperoxide
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作者 Valentin N. Sapunov Aleksandr A. Petukhov Liubov A. Petukhova 《Journal of Chemistry and Chemical Engineering》 2013年第4期356-363,共8页
The kinetics of epoxidation of methylbutene with structurally identical methylbutane hydroperoxide was studied in the presence of a molybdenum catalyst. The analysis of the rate curves suggested the most probable sche... The kinetics of epoxidation of methylbutene with structurally identical methylbutane hydroperoxide was studied in the presence of a molybdenum catalyst. The analysis of the rate curves suggested the most probable scheme of the process. The revealed features of the process and its mathematical description make it possible to more competently design a reactor unit for the commercial production of isoprene according to the developed scheme. The main kinetic constants were calculated. 展开更多
关键词 Kinetic 2-methylbutene-2 EPOXIDATION 2-methylbutane hydroperoxide molybdenum catalyst mathematical description.
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Complexes of Rice Husks Ash for Oxidation of Cyclohexene
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作者 Krassimir Vassilev Sevdalina Turmanova Svetlana Genieva 《Journal of Environmental Science and Engineering(A)》 2012年第7期956-966,共11页
The cheap raw rice husks and the products of their thermal degradation WRHA (white rice husk ash) and BRHA (black rice husk ash), after vigorously grounding and mixing, can successfully be used as a catalyst suppo... The cheap raw rice husks and the products of their thermal degradation WRHA (white rice husk ash) and BRHA (black rice husk ash), after vigorously grounding and mixing, can successfully be used as a catalyst support to replace the existing expensive ones. The aim of the present research is to prepare new metal-immobilized complexes based on rice husks and to study their catalytic activity in the oxidation of cyclohexene with tert-butylhydroperoxide. The corresponding metal complexes were obtained by interaction of RRH (raw rice husks) or thermally treated WRHA in air atmosphere. The complexes were obtained from aqueous solutions of various salts such as FeCl2.4H2O, COCl2.6H2O, VOSO4.5H2O and Na2MoO4.2H2O at room temperature. The rice husks-supported metal complexes were identified by infrared spectroscopy. The structure of the iron-containing polymeric materials was evaluated by Mossbauer spectroscopy. The catalytic activity of the molybdenum-containing complex catalyst in the principal epoxidation reaction was higher than that of the vanadium-containing one, whereas, the opposite order of activities was found for the side reaction of allylic hydroxylation of cyclohexene. Under selected reaction conditions, the yields of the principal reaction products cyclohexene oxide (1,2-epoxycyclohexane) and 2-cyclohexene-1-ol were 36.4% and 22.7%, respectively. 展开更多
关键词 Rice husks ash metal complexes OXIDATION properties.
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Theoretical Investigations of the Catalytic Role of Water in Propene Epoxidation on Gold Nanoclusters: A Hydroperoxyl- Mediated Pathway 被引量:9
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作者 Chun-Ran Chang Yang-Gang Wang Jun Li 《Nano Research》 SCIE EI CAS CSCD 2011年第1期131-142,共12页
We report a comprehensive theoretical investigation of the catalytic reaction mechanisms of propene epoxidation on gold nanoclusters using density functional theory (DFT). We have shown that water acts as a catalyti... We report a comprehensive theoretical investigation of the catalytic reaction mechanisms of propene epoxidation on gold nanoclusters using density functional theory (DFT). We have shown that water acts as a catalytic promoter for propene epoxidation on gold catalysts. Even without reducible supports, hydroperoxyl (OOH) and hydroxyl (OH) radicals are readily formed on small-size gold clusters from co-adsorbed H20 and 02, with energy barriers as low as 4-6 kcal/mol (1 cal = 4.186 J). Propene epoxidation occurs easily through reactions between C3H6 and the weakened O-O bond of the OOH radicals on the surfaces of gold clusters. 展开更多
关键词 Gold nanocluster propene epoxidation hydroperoxyl radical density functional theory
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The applications of hypervalent iodine(Ⅲ) reagents in the constructions of heterocyclic compounds through oxidative coupling reactions 被引量:7
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作者 ZHENG ZiSheng ZHANG-NEGRERIE Daisy +1 位作者 DU YunFei ZHAO Kang 《Science China Chemistry》 SCIE EI CAS 2014年第2期189-214,共26页
Hypervalent iodine(Ⅲ)reagents have been vastly used in many useful organic transformations.In this review article,we highlight the strategies that used the common hypervalent iodine(Ⅲ)reagents as oxidants to synthes... Hypervalent iodine(Ⅲ)reagents have been vastly used in many useful organic transformations.In this review article,we highlight the strategies that used the common hypervalent iodine(Ⅲ)reagents as oxidants to synthesize the heterocyclic compounds,based on the patterns of bond formation during the construction of the heterocyclic backbones. 展开更多
关键词 hypervalent iodine(III) reagent oxidative coupling bond formation strategy HETEROCYCLES
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Hot water as a mild Brφnsted acid catalyst in ring opening reactions of epoxides 被引量:1
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作者 XU ZhaoBing QU Jin 《Science China Chemistry》 SCIE EI CAS 2011年第11期1718-1725,共8页
Ring opening of extremely hydrophobic epoxides with water, amines, sodium azide and thiophenol was realized in the mixture solvent of water and 1, 4-dioxane under reflux condition. Hot water was believed to act as a m... Ring opening of extremely hydrophobic epoxides with water, amines, sodium azide and thiophenol was realized in the mixture solvent of water and 1, 4-dioxane under reflux condition. Hot water was believed to act as a mild Bronsted acid catalyst in the epoxide-opening reactions. 展开更多
关键词 epoxide-opening reaction 1 4-dioxane hot water Bronsted acid catalyst
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Theoretical insight into methanol steam reforming on indium oxide with different coordination environments 被引量:2
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作者 Jinglin Wang Haifeng Wang P.Hu 《Science China Chemistry》 SCIE EI CAS CSCD 2018年第3期336-343,共8页
Indium oxide(In_2O_3) has demonstrated to be an effective non-noble metal catalyst for methanol steam reforming reaction(MSR).However, the reaction mechanism of MSR and crucial structure-activity relations determining... Indium oxide(In_2O_3) has demonstrated to be an effective non-noble metal catalyst for methanol steam reforming reaction(MSR).However, the reaction mechanism of MSR and crucial structure-activity relations determining the catalytic performance of In_2O_3 are still not fully understood yet. Using density functional theory(DFT) calculation, we systematically investigate the MSR process over a high-index In_2O_3(211) and a favoured catalytic cycle of MSR is determined. The results show that In_2O_3(211) possesses excellent dehydrogenation and oxidizing ability, on which CH_3 OH can readily adsorb on the In4 c site and be easily activated by the reactive lattice oxygens, resulting in a total oxidation into CO_2 rather than CO, while the H_2 formation through surface H–H coupling limits the overall MSR activity because of the strong H adsorption on the two-coordinated lattice O(O_(2c)). Our analyses show that the relatively inert three-coordinated lattice O(O_(3c)) could play an important catalytic role. To uncover the influence of the local coordination of surface In atoms and lattice O on the catalytic activity, we evaluate the activity trend of several types of In_2O_3 surfaces including(211),(111), and(100) by examining the rate-limiting, which reveals the following activity order:(211)>(111)>(100). These findings provide an in-depth understanding on the MSR reaction mechanism over In_2O_3 catalysts and some basic structure-activity relations at the atomic scale, could facilitate the rational design of In_2O_3-based catalysts for MSR by controlling the local coordination environment of surface active sites. 展开更多
关键词 steam reforming reaction DFT In2O3 (211) reaction mechanism DEHYDROGENATION structure-activity relation
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The cycloaddition reaction using visible light photoredox catalysis 被引量:1
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作者 Yu Liu Renjie Song Jinheng Li 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第2期161-170,共10页
In recent years, visible light photoredox catalysis has emerged as an important research area in synthesis. In this review, we describe the recent progress in the visible light induced cycloaddition reactions, includi... In recent years, visible light photoredox catalysis has emerged as an important research area in synthesis. In this review, we describe the recent progress in the visible light induced cycloaddition reactions, including [2+2], [3+2], [4+2] and [2+2+2] cycloadditions, for the construction of four-, five- or six-membered cycles and polycycles. Furthermore, the mechanisms for these transformations are also discussed, in which the formation of the radicals is initiated by a visible light photoredox catalysis process. 展开更多
关键词 CYCLOADDITION ANNULATION visible light PHOTOREDOX
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Enantioselective epoxidation of nonfunctionalized alkenes catalyzed by recyclable new homochiral bis-diamine-bridged bi-Mn(salen) complexes
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作者 HUANG XueMei FU XiangKai +2 位作者 JIA ZiYong MIAO Qiang WANG GuoMing 《Science China Chemistry》 SCIE EI CAS 2013年第5期604-611,共8页
Three new homochiral bis-diamine-bridged bi-Mn(salen) complexes were synthesized. Their catalysis on asymmetric epoxidation of a-methylstyrene, styrene and indene was studied with NaC10 and m-CPBA as oxidants respec... Three new homochiral bis-diamine-bridged bi-Mn(salen) complexes were synthesized. Their catalysis on asymmetric epoxidation of a-methylstyrene, styrene and indene was studied with NaC10 and m-CPBA as oxidants respectively. This homogeneous catalyst exhibited comparable catalytic activity and enantioselectivity to the Jacobsen's catalyst in the asymmetric epoxidation of unfunctionalized olefins. Furthermore, the catalyst could be conveniently recovered and reused at least five times without significant losses of both activity and enantioselectivity. Specially, it also could be efficiently used in large-scale reactions with superior catalytic disposition being maintained at the same level, which provided the potential for the applications in industry. The effect of axial bases, temperature and solvent on activity and enantioselectivity of the catalytic system were also studied. 展开更多
关键词 homochiral bi-Mn(salen) complex ENANTIOSELECTIVE asymmetric epoxidation unfunctionalized olefins
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