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1.
应用Y分子筛吸附Fe(CO)5、Co(CO)3NO和Mo(CO)6的温和热分解制备分子筛负载金属催化剂,从分子筛交换阳离子和吸附金属络合物之间的相互作用说明其CO加氢产物的分布特点。实验结果表明,分子筛内阳离子和吸附金属络合物间的相互作用显著影响制得催化剂的结构和反应的产物分布。由于金属络合物和分子筛内阳离子间的电子转移,使NiY附载金属催化剂显示出高的CO转化率和甲烷选择性。在CuY中,这种电子  相似文献   

2.
姜明  伏义路 《催化学报》1998,19(2):130-133
Co(CO)3NO吸附进入Y分子筛超笼,笼中不同交换阳离子对其吸附和分解起不同作用。研究不同交换阳离子Y分子筛上Co(CO)3NO的吸附和热分解发现,吸附金属络合物部分脱羰基或脱亚硝基,并伴有少量吸附物种的脱附。NaY上的热分解产物主要为金属钴;NiY,尤其是CuY上,阳离子和吸附物种作用较强,甚至发生电子转移,热分解产物为Co(0)和Co(Ⅱ)混合物。  相似文献   

3.
Co(CO)3NO吸附进入Y分子筛超笼,笼中不同交换阳离子对其吸附和分解起不同作用.研究不同交换阳离子Y分子筛上Co(CO)3NO的吸附和热分解发现,吸附金属络合物部分脱羰基或脱亚硝基,并伴有少量吸附物种的脱附.NaY上的热分解产物主要为金属钴;NiY,尤其是CuY上,阳离子和吸附物种作用较强,甚至发生电子转移,热分解产物为Co(0)和Co(Ⅱ)混合物  相似文献   

4.
姜明  伏义路 《催化学报》1998,19(2):134-138
采用红外光谱表征了含不同阳离子的Y分子筛上Co(CO)3NO的吸附和分解及其和阳离子的作用。结果表明,Co(CO)3NO吸附后主要形成Co(CO)xNO(x=2,3),并出现热稳定性较高的Co(NO)2^2+。产生Co(NO)2^2+的机制和最终分解产物与分子筛阳离子的性质有关。NaY上Co(NO)xNO歧化产生少量Co(NO)2^2+,分解产物主要为Co(0);CoY中Co^2+的存在部分避免了  相似文献   

5.
杂原子ZSM-5分子筛催化剂上C_3H_6催化还原NO反应的研究张文祥,贾明君,张春雷,吴通好,敖雪桔(吉林大学化学系,长春,130023)(齐齐哈尔环境监测中心站)关键词杂原子分子筛,一氧化氮,催化还原NOx对环境的危害已引起了人们的广泛重视。自Iw...  相似文献   

6.
采用红外光谱表征了含不同阳离子的Y分子筛上Co(CO)3NO的吸附和分解及其和阳离子的作用.结果表明,Co(CO)3NO吸附后主要形成Co(CO)xNO(x=2,3),并出现热稳定性较高的Co(NO)2+2.产生Co(NO)2+2的机制和最终分解产物与分子筛阳离子的性质有关.NaY上Co(CO)xNO歧化产生少量Co(NO)2+2,分解产物主要为Co(0);CoY中Co2+的存在部分避免了Co(CO)xNO的歧化,分解得到的Co(0)含量较高;NiY,尤其CuY阳离子和吸附物种发生电子转移,形成NO+中间物种,氧化Co(0)产生Co(NO)2+2,分解产物为Co(0)和Co(Ⅱ)的混合物.  相似文献   

7.
应用漫反射红外光谱测定了不同的铜分子筛经真空自还原后吸附CO的基频,组频和泛频谱带,结果表明,CO压力较低时,形成Cu(Ⅰ)(CO)吸附物种,其种类与分子筛的结构特性有关。随CO2压力增高,部分吸附物种转变为Cu(Ⅰ)(CO)2,分析Cu(Ⅰ)(CO)基频和组频谱带可得到比C-O伸缩振动更灵敏的反映Cu(Ⅰ)和CO作用的Cu(Ⅰ)-C伸缩振动频率。  相似文献   

8.
TS分子筛催化剂上烯丙基氯的环氧化性能   总被引:5,自引:2,他引:5  
在TS-1分子筛催化剂上,研究了以H2O2为氧源的烯丙基氯液固多相环氧化反应。结果表明,TS-132分子筛是该反应的有效催化剂,H2O2转化率达80%,目的产物氧氯丙烷选择性达90%,用程序升温脱附(TPD)和程序升温表面反应(TPSR)研究了H2O2和烯丙基氯在催化剂表面的吸附状态,结果表明,TS-1-32分子筛对H2O2和烯丙基氯有较大吸附容量和吸附强度,使它们在反应温度下有较大的表面浓度,  相似文献   

9.
韩一帆  汪仁 《催化学报》1997,18(2):168-170
不同制备方法对Cu┐ZSM┐5沸石分子筛上NO分解反应活性的影响*韩一帆汪仁(华东理工大学工业催化研究所,上海200237)关键词Cu-ZSM-5沸石分子筛,一氧化氮,催化分解,直接粘混法,离子交换法如何减少各类污染源所排放的氮氧化物(NOx)对环境...  相似文献   

10.
氧化铝基表层镁铝尖晶石的研究──Ⅲ.Pd/MgAl_2O_4-γ-Al_2O_3上NO的吸附态及其与CO的反应刘希尧(石油化工科学研究院,北京100083)关键词钯催化剂,表层镁铝尖晶石,一氧化氮吸附态,一氧化氮还原氧化铝载耙催化剂上的CO还原NO反...  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

19.
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   

20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

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