首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
Ni-Cu/ZnO双金属催化剂催化CO加氢反应   总被引:5,自引:0,他引:5  
王亚权 《催化学报》1998,19(2):166-168
iCu/ZnO双金属催化剂催化CO加氢反应王亚权(天津大学化工学院一碳化工国家重点实验室,天津300072)关键词镍,铜,氧化锌,负载型催化剂,双金属催化剂,一氧化碳,加氢分类号O643一种金属担载在载体上,可以产生多种相互作用,如金属载体强相互...  相似文献   

2.
高分子负载催化剂在硝基苯加氢中的双金属协同效应   总被引:7,自引:0,他引:7  
高分子负载催化剂在硝基苯加氢中的双金属协同效应*郦海青廖世健**徐筠余道容(中国科学院大连化学物理研究所,大连116023)关键词聚乙烯吡咯烷酮,负载型催化剂,双金属催化剂,协同效应,硝基苯,加氢,苯胺在多相催化中,双金属和多金属催化剂是常见的,但在...  相似文献   

3.
Ni催化剂上一氧化碳加氢反应机理研究   总被引:3,自引:0,他引:3  
Ni催化剂上一氧化碳加氢反应机理研究胡云行,万惠霖,关玉德,林恒生(厦门大学化学系,固体表面物理化学国家重点实验室,厦门,361005)(中国科学院山西煤炭化学研究所,太原)关键词脉冲法,一氧化碳,加氢,反应机理自本世纪初报道了一氧化碳加氢生成甲烷以...  相似文献   

4.
负载于γ-Al_2O_3上的PPN[FeCo_3(CO)_(12)]簇合物作为催化剂前体,在CO加氢反应中显示出了较好的催化活性和对低碳烃的选择性。本文系统地考察了反应温度、反应时间、合成气比和气体空速对CO加氢反应,CO转化率和产物分布的影响。借助于ICP分析、电镜和原位FT-IR跟踪技术,对负载型双金属簇催化剂的金属负载量、催化剂表面状态和脱羰过程中催化剂表面结构的变化进行了分析和表征,获得了一些有意义的结果。  相似文献   

5.
ZrO_2/γ-Al_2O_3体系中氧化物间的相互作用及其时催化性能的影响苏桂琴,张文忠,杨华,高润雄,王欣玫,殷元骐(中国科学院兰州化学物理研究所,兰州730000)关键词氨,一氧化碳,吸附,加氢,氧化锆,氧化铝,负载型催化剂近年来人们对金属与载体间?..  相似文献   

6.
聚合物固载NiAg双金属催化剂Ⅲ.聚合物比表面积对催化剂分散度和活性的影响吴世华朱常英黄唯平沈虎峻沈欣李连荣(南开大学化学系,天津300071)关键词镍,银,双金属催化剂,树脂,比表面积,固载型催化剂,加氢,燃料电池电极溶剂化金属原子浸渍(SMA...  相似文献   

7.
本文利用XPS、In-situIR、Mossbauer和EPR谱对负载型Fe-Co双金属簇催化剂在负载前后,反应前后催化剂表面状态的变化和表面原子的相互作用进行了研究。实验表明,负载后双金属簇中的CoFe_3金属簇骨架与担体的表面原子发生了强相互作用。在反应条件下,簇骨架发生了断裂,在担体表面形成金属碎片,并成为CO加氢反应的催化活性中心。  相似文献   

8.
本文利用XPS、In-situ IR、Mossbauer和ERR谱对负载型Fe-Co双金属簇催化剂在负载前后,反应前后催化剂表面状态的变化和表面原子的相互作用进行了研究。实验表明,负载后双金属簇中的CoFe3金属簇骨架与担体的表面原子发生了强相互作用。在反应条件下,簇骨架发生了断裂,在担体表面形成金属碎片,并成为CO加氢反应的催化活性中心。  相似文献   

9.
聚合物固载Ni┐Ag双金属催化剂Ⅱ.催化剂的催化性质吴世华朱常英王连邦张松桢(南开大学化学系,天津300071)关键词镍,银,聚合物固载金属催化剂,加氢,燃料电池电极溶剂化金属原子浸渍(SMAI)技术是制备聚合物负载零价金属催化剂的一个非常有用的方法...  相似文献   

10.
以乙二醇为还原剂,通过微波热辐射制备得到稳定的Pt/Ru双金属胶体纳米簇,各颗粒粒径在1~2nm范围。考察了聚合物聚乙烯吡咯烷酮(PVP)对Pt/Ru双金属纳米簇表面原子组成及催化性能的影响。结果表明,PVP与金属前体之间的不同相互作用影响Pt/Ru双金属纳米簇的形成。在Pt/Ru双金属纳米簇形成之前加入PVP,Pt原子更容易富集在双金属表面,有利于增加Pt在催化反应中的作用。在PVP稳定的Pt/Ru双金属纳米簇中,除了零价态的Pt、Ru单质外,还存在氧化态的Pt化合物,归因于PVP与Pt前体的相互作用。在环己烯加氢反应中,PVP-Pt/Ru双金属纳米簇显示出比单金属纳米簇更优越的催化性能。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
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   

18.
19.
《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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号