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Fe—Silicalite—2催化剂表面CO2加氢反应性能的研究 总被引:3,自引:0,他引:3
研究了Fe/Silicalite-2催化剂CO2加氢低碳烯烃反应性能,利用CO2-TPD,CO2/H2-TPSR和CO/H2-TPSR表征手段,考察了铁含量及MnO助剂对Fe/Silicalite-2催化剂CO2吸附脱附及加氢反应性能的影响,表明随铁含量增加可提高催化剂对CO2的吸附能力,有利于提高CO2加氢反应的转化率。 相似文献
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Yuh-Wern Wu 《中国化学会会志》1996,43(6):507-509
The relative rates for the addition reactions of tert-butyl radical to 2-substituted ally chlorides I have een determined. The correlation of log k/k0, vs. σm gives a ρ mvalue of 3.59 with correlation coefficient of 0.930. When the substituent CH2Cl is excluded, correlation coefficient raises to 0.990 and ρ value becomes 3.39. The large p value and the deviation of relative rate of substituent CH2C1 are discussed. 相似文献
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M. Burcu Gürdere Hayreddin Gezegen Yakup Budak Mustafa Ceylan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):889-898
Abstract A series of novel β-mercapto carbonyl compounds (3a–z), methyl 2-(3-oxo-1,3-diarylpropylthio)acetate, were synthesized and characterized via iodine-catalyzed addition of methyl thioglycolate to chalcones (1a–z). Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
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Dr. Debdeep Mandal T. Ilgin Demirer Dr. Tetiana Sergeieva Dr. Bernd Morgenstern Haakon T. A. Wiedemann Prof. Dr. Christopher W. M. Kay Dr. Diego M. Andrada 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217184
Electrophilic AlIII species have long dominated the aluminum reactivity towards arenes. Recently, nucleophilic low-valent AlI aluminyl anions have showcased oxidative additions towards arenes C−C and/or C−H bonds. Herein, we communicate compelling evidence of an AlII radical addition reaction to the benzene ring. The electron reduction of a ligand stabilized precursor with KC8 in benzene furnishes a double addition to the benzene ring instead of a C−H bond activation, producing the corresponding cyclohexa-1,3(orl,4)-dienes as Birch-type reduction product. X-ray crystallographic analysis, EPR spectroscopy, and DFT results suggest this reactivity proceeds through a stable AlII radical intermediate, whose stability is a consequence of a rigid scaffold in combination with strong steric protection. 相似文献
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CuX/bpy催化体系中甲基丙烯酸甲酯的原子转移自由基聚合 总被引:12,自引:2,他引:12
讨论了以α-溴代丙酸乙酯(EPN-Br)为引发剂、卤化亚铜(CuX)/联二吡啶(bpy)为催化剂,80℃下,甲基丙烯酸甲酯(MMA)地不同溶剂中的原子转移自由基聚合(ATRP)反应。通过对催化剂CuBr或CuCl及几种溶剂的考察,发现在80℃下EPN-Br/CuBr/bpy能有效控制丙烯酸甲酯(MA)的本体ATRP反应,但并不能很好地控制MMA在EAc中的聚合反应为一可控聚合过程,引发效率为0.8 相似文献
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银促进的TiO2光催化降解甲基橙 总被引:14,自引:0,他引:14
采用溶胶-凝胶和水热协同法制备了不同Ag含量的负载型Ag-TiO2样品,这些样品具有较大的比表面积和较小的粒径. 适量负载金属银后的TiO2在紫外及可见光下的光催化活性均得到提高. 银在TiO2上的最佳负载量为0.15%, 过高的负载量反而会降低TiO2光催化降解甲基橙的活性. 由于反应机理的不同,银负载对TiO2可见光下催化活性的提高要明显高于对其紫外光下催化活性的提高. 在可见光照射下,从激发态染料注入到TiO2导带的电子迅速转移到了Ag原子簇, Ag原子簇通过促进电荷分离抑制了电子和染料正离子自由基的复合,从而促进了光催化过程. 研究结果表明,有效地促进电荷分离以及激发态电子和氧气分子的反应是提高染料敏化光催化活性的关键. 相似文献
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Vasil'eva T. T. Mysova N. E. Chakhovskaya O. V. Terent'ev A. B. 《Russian Journal of Organic Chemistry》2002,38(7):1014-1017
The yield and structure of products of the Barbier-type addition of alkyl halides (perfluorobutyl iodide, allyl bromide, allyl iodide, and hexyl iodide) to para-substituted benzaldehydes in the presence of pentacarbonyliron are essentially determined, on the one hand, by the ability of alkyl halide to be reduced to carbanion and, on the other, by the electrophilicity of the aldehyde reaction center which in turn depends on the nature of para-substituent in the aromatic ring. 相似文献
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A Zn/NH4Cl system was exploited at room temperature to promote the Michael addition reaction of various primary and secondary amines with α,β-unsaturated esters,nitriles,amides,and ketones to give the corresponding saturated amines under the mild condition in high yield. 相似文献
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The Investigation of Free Radical Intermolecular Addition Following Free Radical SH2′ Cyclization Reactions 下载免费PDF全文
The photolytic radical intermolecular addition following SH2′ cyclization reactions of t‐BuHgCl with 1‐bromo‐4‐(2‐choroallyloxy)‐but‐2‐ene and (E)‐4‐bromobut‐2‐enyl acrylate gave the good yields and the chemoselectivity of the cyclized product. The high stereoselectivity of the reactions is discussed. 相似文献
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Variously N-protected α-aminoaldehydes exhibit reasonable diastereoselectivity in the Baylis-Hillman coupling1 with methyl acrylate to provide either primarily syn or anti α-methylene-β-hydroxy-γ-amino esters. 相似文献
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A new K-Fe-MnO/Si-2 catalyst has been developed for CO2 hydrogenation, which exhibits a fascinating reaction activity and light olefin selectivity for CO2 hydrogenation. Over the catalyst, it is observed that olefin selectivity increases apparently with reaction temperature and/or GHSV, while decreases when reaction pressure is up. Furthermore, the catalyst exhibits a better stability for CO2 hydrogenation. However, coke deposited on catalyst surface is formed at the beginning of the reaction period and then reached a stable state during CO2 hydrogenation. Generally, the K-Fe-MnO/Si-2 catalyst can be regenerated for CO2 hydrogenation, the same selectivity of C2=-C4=alkenes is regained without any decrease in catalyst activity with time on stream. 相似文献
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以苯胺和生物质来源的丙三醇为反应原料,在铁促进的Cu/SiO2-Al2O3催化剂上气相合成了3-甲基吲哚,采用X射线光电子能谱、氢气程序升温还原(H2-TPR)、X射线衍射、透射电子显微镜、电感耦合等离子体发射光谱(ICP)、氨程序升温脱附(NH3-TPD)以及热重(TG)分析等技术对催化剂进行了表征.结果表明,向Cu/SiO2-Al2O3催化剂加入铁助剂不仅能明显提高催化剂的活性和选择性,而且能大大改善催化剂的稳定性.在Cu-Fe/ SiO2-Al2O3催化剂上,反应3h,3-甲基吲哚收率能够达到48%,而且催化剂经过再生可以重复使用,即使反应43 h,其产物收率也没有明显的降低.各种表征表明,向Cu/SiO2-Al2O3加入铁助剂能增强铜和载体之间的相互作用,由此大大提高了铜粒子在载体表面的分散度,并且有效减少了反应过程中铜组分的流失;此外,铁助剂还能显著减少催化剂的中强酸中心数,增加弱酸中心数,从而提高3-甲基吲哚的选择性,并且抑制了积炭的形成. 相似文献
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在铜盐催化下,苯乙酮衍生的烯胺与重氮苯乙酸甲酯(1)发生一种新型加成反应.该反应并不产生预期的环丙烷化合物,而是以较高的收率产生γ-酮酯化合物--4-氧代-2,4-二苯基丁酸甲酯.实验结果表明环状的和脂肪族的二级胺形成的烯胺都能与1发生加成反应,其中吗啉衍生的烯胺参与加成反应的产率最高. 相似文献
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K2O is a vital promoter to the Fe-MnO/silicalite-2 catalyst for light olefin formation from CO2 hydrogenation. With addition of it into the Fe-MnO/Si-2 catalyst the selectivity to light olefins increases greatly, while CH4 formation is inhibited evidently. Meanwhile, an obvious increment in CO2 conversion is also observed with the addition of K2O promoter. And it has been manifested that adding K2O to the Fe-MnO/Si-2 catalyst leads to remarkable increases in both the capacity and strength of the strong CO2 and CO adspecies. These produce much more[Cad] via their disproportionation at higher temperatures. This results in increase in the CO2 conversion and the selectivity to light olefins, and a decrease in CH4 formation. 相似文献