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乙醇催化制氢研究进展* 总被引:13,自引:0,他引:13
氢是未来理想的清洁能源之一,燃料电池特别是燃料电池电动车的发展对氢源和制氢方法提出了新的要求,从乙醇催化制氢已经受到普遍关注。本文对乙醇催化制氢发展的最新研究进展进行了比较详细的综述和讨论。 相似文献
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Co/Fe催化剂乙醇裂解和部分氧化制氢研究 总被引:5,自引:2,他引:5
采用共沉淀法制备的Co/Fe催化剂催化乙醇裂解和部分氧化制氢反应,考察了反应温度对两种途径反应的影响。结果发现,Co/Fe催化剂对乙醇部分氧化制氢显示出较高的氢选择性,且稳定性较好;该催化剂对乙醇裂解制氢也具有较高的氢选择性,但其稳定性很很差。XRD表征结果表明,在催化乙醇部分氧化反应后,Co70Fe30催化剂中存在CoFe合金和CoO相;而催化乙醇裂解反应后,Co70Fe30催化剂中仅存在CoFe合金,即CoFe合金可能是裂解反应的活性组分。 相似文献
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采用溶胶-凝胶法制备了纳米CoFe_2O_4催化剂并用于乙醇裂解和部分氧化制氢反应. CoFe_2O_4催化剂对乙醇催化裂解反应表现出较低的催化活性, 其主要原因可能是催化剂表面积碳以及催化剂粒径的长大. 而纳米CoFe_2O_4催化剂对乙醇部分氧化制氢反应具有良好的催化性能. TPR和XRD结果表明尖晶石结构的CoFe_2O_4相在乙醇部分氧化反应过程中发生了结构变化, 部分生成了CoFe合金相. 另外, 催化剂的粒径没有明显增大. 推测纳米CoFe_2O_4催化剂具有良好催化性能是尖晶石结构的CoFe_2O_4和合金相的协同作用所致. 相似文献
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利用电解水制氢来储存太阳能是未来能源发展的一大趋势。 水的阳极氧化是这一过程中最重要也是最复杂的一步。 因此,设计稳定而高效的水氧化催化剂是电解水制氢的关键。 目前,研究比较成熟的是基于贵金属钌的水氧化催化剂,但由于其价格昂贵、储量较少无法大规模利用。 铁作为钌的同族元素用于水氧化催化近年来受到了越来越多的关注。 本文从铁基阳极水氧化催化剂研究现状、制备方法、催化体系及机理3个方面对电解水铁基阳极催化剂进行了综述。 分析其当前存在的问题,为水氧化催化剂的进一步研究设计提供参考。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献