共查询到18条相似文献,搜索用时 173 毫秒
1.
在水和有机溶剂中,在碱性条件下,用相转移催化法,由保险粉一步还原(-)-香芹酮制成了二氢香芹醇。本文就还原剂用量、反应时间、溶剂性质和相转移催化剂的种类对还原反应的影响进行了研究,找出较好的反应条件,使二氢香芹醇的收率达到70%。 相似文献
2.
在水和有机溶济中,在碱性条件下,用相转移催化法,由保险粉一步还原1-香芹酮制成了二氢香芹醇.本文就还原剂用量、反应时间、溶剂性质和相转移催化剂的种类对还原反应的影响进行了研究,找出较好的反应条件,使二氢香芹醇的收率达到70%。 相似文献
3.
4.
5.
硫酸氢钾是一种廉价、有效和环境友好的合成反应催化剂,硫酸氢钾催化的化学反应具有条件温和、收率较高、后处理工艺简单和环境友好等特点。综述了硫酸氢钾在催化有机合成反应中研究的新进展。 相似文献
6.
次磷酸及其盐类在催化剂的作用下,可以还原碳碳双键,碳碳三键,碳氮双键,碳氮三键和碳氧双键.次磷酸盐为氢源的氢转移反应经济安全无污染,它还原有机化合物的反应及产物结构也独特之处.本文对次磷酸盐作为氢源在碳碳双键还原上的应用做了一些综述. 相似文献
7.
传统工业合成氨Haber-Bosch工艺条件要求严苛,并且存在高能耗以及高CO2排放问题。电催化氮气还原(nitrogen reduction reaction, NRR)是一种在常温常压下利用氮气合成氨的新工艺,具有成本低、反应条件温和、环境友好等优势。但该反应所需过电位较高,水解析氢反应(hydrogen evolution reaction, HER)竞争明显,导致电流密度和选择性较低,无法达到工业应用水平。本文在介绍电催化NRR合成氨的反应机理的基础上,主要从氮气分子的吸附活化和电还原阶段反应过程出发,综述了电催化氮气还原合成氨反应中HER与NRR的竞争机制。重点梳理了通过设计催化剂和反应体系抑制HER的国内外最新研究成果,最后对电催化NRR合成氨面临的挑战和机遇进行了展望。 相似文献
8.
9.
10.
11.
Hydrogen transfer from donor solvent to coal must involve reactions such as hydrogen donation to free radicals and hydrogenation of aromatic structures. The relative reactivities of five typical hydrogen donor solvents, more reactive than tetralin, were determined using a competing elimination reaction in the liquefaction of a bituminous coal at 400 °C and a brown coal at 350 °C. 9,10-Dihydroanthracene, 9,10-dihydrophenanthrene and 1,2,3,4-tetrahydroquinoline exhibited outstanding hydrogen donating ability. Further, the relative reactivities of five mild hydrogen donor solvents such as acenaphthene and indan were determined by a similar elimination reaction using a bituminous coal at 450 °C. 相似文献
12.
1 INTRODUCTION
Hydrogen evolution reaction is an important reaction to produce high purity hydrogen for use in applications such as fertilizers (synthesis of ammonia),food (hydrogenation of fats and oils),petrochemical industry(hydrocracking of petroleum), metallurgical industry (reducing agent in the metallurgical and semiconductors industries) and alkaline production. The main operating cost of the process is the cost of electricity. 相似文献
13.
在温和反应条件下探讨了催化剂,芳烃及硫对金属催化剂催化的1-甲基萘(1-MN)及二91-萘)甲烷(DNM)加氢反应的添加效应,结果表明:Fe和Ni对促进1-MN和DNM的加氢非常有效,而供氧溶剂和多环芳烃却显著降低1-MN和DNM的加氢转化率,加入硫显著障碍了加氢反应,却大大促进芳烃加氢裂解反应,初步探讨了有关的反应机理。 相似文献
14.
RuH2(PPh3)4 has been immobilized on swellable polyacrylate matrices to provide heterogenized carboxylate-derivatives. These swellable polymer supported ruthenium (II) complex catalysts have been used in the transfer hydrogenation of aldehydes. Hydrogen donors are formate salt, cyclohexanol, and benzyl alcohol. The catalysts exhibit good activity for hydrogen transfer reduction of aldehydes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
15.
Wan Ping Chen Xiang Ping Jiang Yu Wang Zhi Peng Helen Lai Wah Chan 《Journal of the American Ceramic Society》2003,86(4):735-37
Water-induced degradation of barium titanate (BTO) ceramics has been investigated using electrochemical hydrogen charging, in which the silver electrodes of BTO ceramic specimens are made cathodes in a 0.01 M NaOH solution to evolve hydrogen by electrolysis of water. After 80 h of treatment, the resistance of BTO decreases by ∼3 orders of magnitude, and the dielectric loss obviously increases. The degradation can be explained by the reduction reaction of atomic hydrogen with BTO. Hydrogen acts as a donor in BTO, and electrons are formed by the reduction. It is proposed that the reduction reaction of atomic hydrogen at ambient temperature by electrolysis of water is an important origin for degradation of BTO-based ceramic devices. 相似文献
16.
Wilfrid Jochum Dominik Eder Gernot Kaltenhauser Reinhard Kramer 《Topics in Catalysis》2007,46(1-2):49-55
Hydrogen treatment of Pt/TiO2 leads to an exceptional increase in electric conductivity even at moderate temperature presumably due to the formation of
donor electrons during a superficial reduction process. Interestingly, after cooling to lower temperatures that are typically
applied for catalytic reactions the observed high conductivity was largely preserved. The enhanced charge carrier density
in titania is assumed to cause a considerable charge transfer between support and metal. In this work we show that this charge
transfer is correlated with typical catalytic parameters (e.g. hydrogen adsorption capacity and catalytic activity for a hydrocarbon
skeleton reaction). Based on these observations we suggest and discuss a modified charge transfer mechanism in addition to
the decoration mechanism as a possible reason for the SMSI effect occurring during hydrogen treatment already at moderate
temperatures.
Dedicated to Konrad Hayek. 相似文献
17.
研究了共轭二烯烃类聚合物在贮氢合金氢化物存在下双键加氢的情况。结果表明AB;型贮氢合金[包括LaNi5和MINi5-x(CoMnAl)8]可催化NBR、NR、BR、SBS等共轭二烯烃聚合物双键加氢,其氢化度分别可达33.5%、31.1%、45.8%、32.3%。采用IR、^1H NMR、碘量分析法等手段对加氢产物进行了分析,表明聚合物中双键加氢的同时,NBR中的-C≡N和SBS中的苯环不受影响。此外。研究结果还表明合金组成、表面处理方式等对贮氢合金催化共轭二烯烃类聚合物双键加氢活性有影响。合金氢化物在共轭二烯烃类聚合物双键加氢过程中具有提供氢源与催化双重功能。 相似文献
18.
The electrocatalytic properties of an AB5-type hydrogen storage alloy towards the electrochemical hydrogenation of unsaturated organic compounds have been studied by a solid electrolyte method using electrochemical hydrogenation of nitrobenzene as a model reaction. Voltammetric studies reveal that the kinetics of the nitrobenzene electro-reduction on the hydrogen storage alloy electrode is similar to that on a Ni electrode. Aniline and p-aminophenol are produced as the reaction products. Compared to the Ni electrode, the production of aniline is considerably promoted on the hydrogen storage alloy electrode. Modifying the alloy surface with a thin layer of Cu enhances the reaction selectivity and current efficiency for aniline formation. Compared to a Cu electrode, the electrochemical hydrogenation of nitrobenzene to aniline is promoted on the Cu-modified alloy electrode. The hydrogenation promotion effect is attributed to the chemical reaction between nitrobenzene and metal hydrides that are electrochemically generated in situ. Hydrogen storage alloys therefore make it possible to intensify the electrochemical hydrogenation process of unsaturated organic compounds. 相似文献