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1.
Zn-Al-Ce三元类水滑石的制备及性质研究   总被引:8,自引:1,他引:8  
采用共沉淀法,水热合成层状化合物一硝酸根柱撑锌铝铈三元类水滑石,分别测定了各种单一金属盐溶液及M^2 /M^3 摩尔比为2,Ce^3 /Al^3 摩尔比为0.25的混合金属盐的NaOH滴定曲线,并利用XRD对不同条件下合成产物进行物相分析。实验结果表明:在M^2 /M^2 =2,Ce^3 /Al^3 =0.07~0.50,pH=5.8~6.5条件下进行多种离子共沉淀,并经120℃、6h水热处理后,均能合成结构单一的ZnAlCe—HTLLcs,利用TG—DTlA、FT—IR、ICP对合成物进行了表征,筛选出适宜的合成条件,并对HTLcs层状结构的热行为进行初步研究,结果表明ZnAlCe—HTLcs热稳定性较差,层间结合水、层板羟基及层间客体物种(NO3^-)失去温度在240℃左右,易于转化为复合氧化物,将此复合氧化物应用于NO的催化?肖除反应,680℃下NO的转化率高达近100%。  相似文献   

2.
NiMgAl三元类水滑石的制备研究   总被引:5,自引:0,他引:5  
在Ni(NO3) 2-Mg(NO3) 2-Al(NO3) 3-NaOH体系中,研究了共沉淀法制备NiMgAl三元类水滑石的合成规律。考察了pH值、Ni/Mg/Al比、沉淀生成温度及水热处理条件对合成NiMgAl-HTLcs的影响,借助XRD 、ICP、 FT-IR对合成样品进行表征。实验结果表明,合成NiMgAl-HTLcs的适宜pH范围为5.5~7.0,Ni/Mg=2.0~4.0,水热处理条件为100 ℃,7 h。通过对合成物热行为研究表明,NiMgAl-HTLcs结构开始破坏温度为300 ℃,经焙烧后可得Ni元素高度分散的复合氧化物。  相似文献   

3.
Anionic clay, ZnCuCoAlNO3 and its polyoxometalate intercalates were synthesized, and were characterized by XRD, IR, 31PMAS NMR, DTA and elemental analysis. The pillared products are found to be effective catalysts for oxidation of cyclohexene with molecular oxygen under mild reaction conditions  相似文献   

4.
类水滑石及其杂多阴离子柱撑物的合成与表面酸性研究   总被引:1,自引:0,他引:1  
合成了一些类水滑石和过渡金属取代型杂多酸盐,并由此制备了相应杂多阴离子柱撑水滑石层柱材料。用XRD,IR和元素分析等手段对合成产物进行组成和结构表征,用NH3-TPD,Py-IR研究了合成产物的表面酸性和酸类型,并在异丙醇反应中考察了合成物的酸碱催化行为,结果表明,水滑石和柱撑水滑石均同时存在酸碱中心,且酸碱相对强度与柱阴离子类型密切相关。杂多阴离子进入水滑石层,同时改变了水滑石和杂多酸盐的酸强度  相似文献   

5.
含铜类水滑石催化材料热分解过程的研究   总被引:2,自引:0,他引:2  
共沉淀法合成了Cu0.13Mg0 6Al0.27(OH)2(CO3)0.135·xH2O类水滑石物质 (CuHTlc) ,采用XRD、DTA TG、BET、TEM和27AlMASNMR技术对其热分解过程进行了表征。结果表明 ,在较低焙烧温度时 (低于300℃ ),氢氧根和层间水部分脱除 ,但水滑石仍保持其层状结构 ;500℃时 ,其层状结构被完全破坏 ,出现氧化镁晶相结构 ,随着焙烧温度的进一步升高 ,尖晶石晶相生成。500℃时的焙烧产物具有最大比表面 (193m2·g-1)。当温度高于500℃ ,焙烧产物组成可表示为Cu0.13Mg0.6Al0.27O0.135,CuHTlc的热分解过程可表示为 :Cu0.13Mg0.6Al0.27(OH)2(CO3)0.135·xH2O→Cu0.13Mg0.6Al0.27O0.135 (1 x)H2O 0.135CO2。  相似文献   

6.
The CuCr-Hydrotalcite-like Compounds were synthesized by co-precipitation method. The samples were characterized by XRD, FTIR and N2-adsorption/desorption measurements. The catalytic performance of the material synthesized was evaluated for the synthesis of benzion methyl ether with benzaldehyde and methanol. The result show that well crystallized hydrotalcites are obtained when nCu/nCr molar ratio is 2.0 and final value of pH is 4.3±0.2. The crystal shape is remained the same while crystallinity, surface area, pore structure and activity vary with the molar ratio of Cu to Cr. The catalytic activity is the best when the molar ratio of Cu to Cr is 2.0 at 50 ℃ andreaction time is 90 min. The highest conversion of benzaldehyde could reach 89.56%,while the selectivity of benzoin methyl ether is nearly 100%.  相似文献   

7.
铜铁二元类水滑石化合物的制备及催化性质研究   总被引:1,自引:0,他引:1  
利用共沉淀法合成了CuFe二元类水滑石化合物。测定了不同Cu/Fe比混合盐溶液随沉淀剂NaOH与Na2CO3加入,混合盐体系pH值变化情况,详细探讨了不同因素对类水滑石化合物制备的影响,得到了合成铜铁二元类水滑石化合物的适宜条件,制备出晶相单一、结晶度高的类水滑石化合物,并利用XRD、FTIR、TG-DTA对合成物进行表征。将合成的催化剂引入苯甲醛与正丙醇反应生成安息香异丙醚反应中, 苯甲醛转化率为58%,安息香异丙醚选择性接近于100%。  相似文献   

8.
用液相非稳态共沉淀法制备了Mg-Al 类水滑石(HTlc); Mg-Al HTlc 于450 ℃下焙烧得焙烧类水滑石(CHTlc); 采用结构重建法由CHTlc 制备了十二烷基硫酸根(DS-)插层(改性)类水滑石(DS·HTlc). 研究了邻甲酚在Mg-Al HTlc,CHTlc 和DS·HTlc 上的吸附行为: 邻甲酚在Mg-Al HTlc, CHTlc 和DS·HTlc 上的吸附动力学和等温式均分别符合准二级动力学方程和Freundlich 方程, 且吸附速率和吸附量大小均依次为: DS·HTlc>>CHTlc>HTlc; 在初始pH=5.00~13.00 范围内, 邻甲酚在HTlc 和CHTlc 上的吸附量随pH 值的增加先增加后减小, 随温度的增加而增加, 邻甲酚在DS·HTlc 的吸附量随pH 值和温度的增加而降低; 邻甲酚在HTlc, CHTlc 和DS·HTlc 上的吸附量均随电解质(NaCl)浓度的增加而增加, 探讨了吸附机理. 研究结果表明, DS·HTlc 有望成为一种新型的高效酚类有机污染物处理剂.  相似文献   

9.
均匀沉淀法直接合成有机阴离子柱撑水滑石   总被引:6,自引:1,他引:6  
以尿素为沉淀剂用均匀沉淀法直接合成有机阴离子柱撑水滑石(Layered Double Hydroxides,LDH)及CoAl水滑石等,并用XRD,FT—IR,TGA,TEM等分析手段对所合成的水滑石进行了表征.结果表明,尿素均匀沉淀法可以直接合成有机阴离子柱撑水滑石及CoAl水滑石等,并且可以方便地消除原料中阴离子的干扰,是合成有机阴离子柱撑水滑石及CoAl水滑石等的一个简便快速的新方法。  相似文献   

10.
ZnCuCoAlNO3型四元水滑石及其多氧阴离子柱撑物的合成与催化氧化性能郭军*黄兰芳**矫庆泽张斌蒋大振(吉林大学化学系,长春130023)闵恩泽(石油化工科学研究院,北京100083)关键词:ZnCuCoAlNO3四元水滑石杂多阴离子柱撑物合成催...  相似文献   

11.
Recent results for the preparation of chain-end functionalized polymers using alkyllithium-initiated anionic polymerization are described. Termination with 4-chloro-1,1,1-trimethoxybutane has been used to prepare trimethoxy ortho ester (carboxyl)-functionalized polymers. Functionalization with the oxiranes, glycidoxypropyltrimethoxysilane, 3,4-epoxy-1-butene and 1,1,1-trifluoro-2,3-epoxypropane, has been investigated to prepare trimethoxysilyl-functionalized polymers, 1,3-diene-functionalized macro monomers and trifluoromethyl-functionalized polymers, respectively. Secondary amine-functionalized polymers have been prepared by termination with N-(benzylidene)methylamine and also using an N-benzyl tertiary amine-functionalized alkyllithium initiator followed by hydrogenolysis of the benzyl group.  相似文献   

12.
刘钰  杨向光  王学中  吴越 《化学学报》1999,57(7):782-789
以共沉淀法制提得的水滑石类化合物为催化剂前体,经焙烧可得到一系列尖晶石类化合物Co-M-Al[M=Cr,Mn,Fe,Ni,Cu;n(Co):n(M):n(Al)=3:1:1].通过XRD,比表面测定,化学分析,NO吸附等方法对其进行表征,测定了此系列催化剂对NO催化还原和催化分解的活性,结果发现此系列催化对消除NO具有很高的活性.同时对催化消除NO的机理及过渡金属离子中d轨道电子对催化活性的影响进行了一些探讨。  相似文献   

13.
胡方中  杨华铮 《有机化学》2000,20(5):623-628
综述了近年来液相组合合成的研究进展,主要包括液相组合合成法(LPCS),氟合成,树状载体组合合成及高分子辅助试剂在液相组合合成中的应用等。  相似文献   

14.
韩江政  赵振冬  樊毅  王岚 《化学研究》2013,(2):149-154,158
采用镍铁类水滑石作为吸附剂,对偶氮阴离子染料酸性大红G、活性艳红X-3B和直接耐酸大红4BS废水进行脱色处理,研究了时间、镍与铁的物质的量之比、初始pH和无机电解质添加剂等因素对脱色率的影响,并结合红外光谱和X射线衍射分析结果讨论了其吸附脱色机理.结果表明,三种染料在镍铁类水滑石上的吸附均为层间的阴离子交换吸附和外表面的吸附.通过阴离子交换进入层间后,不同于直接耐酸大红4BS阴离子,酸性大红G和活性艳红X-3B两种阴离子与水滑石层间水分子之间产生氢键作用;在化学键合过程中,染料分子被镍铁类水滑石表面Fe3+氧化,同时偶氮键断裂导致脱色.  相似文献   

15.
Herein, Zinc Oxide nanoflowers (ZnONFs) with low cost, non-hazardous and renewable phytochemicals from plant (Thlaspi arvense) extract were synthesized via facile method under controlled optimized experimental conditions. The as-fabricated Zinc Oxide nanoflowers were comprehensively characterized by UV–visible spectroscopy, Fourier Transform infrared spectroscopy, X-ray diffraction, Scanning electron microscopy, High-resolution transmission electron microscopy, and Energy dispersive spectroscopy techniques. The bio-fabricated Zinc Oxide nanoflowers performed an admirable potential activity against Gram-negative bacterium (Escherichia coli) and significantly inhibited its growth, due to an intracellular generation of reactive-oxygen-species. The photocatalytic performances of as bio-synthesized Zinc Oxide nanoflowers were also tested by reducing 4-nitrophenol and methylene blue. The superior photocatalytic activities of Zinc Oxide nanoflowers are attributed to the high surface area, efficient photogenerated electron and hole separation owing to the capped plant moieties. The as-synthesized Zinc Oxide nanoflowers by green method exhibited a significant antibacterial activity and efficient photocatalytic performances. This synthetic strategy will open a new window for the fabrication of nanomaterial with effective removal of wastewater contaminants and pathogens.  相似文献   

16.
In comparison with zeolites, a variety of Al pillared clays did not prove as promising cracking catalysts, possibly because their Br?nsted sites are hidden. In the less demanding double bond shift isomerization, both catalyst types were comparable probably due to the presence of Lewis sites on both catalysts.  相似文献   

17.
The aim of the present work was to investigate the synthesis,characterization and electrochemical properties of the nitroprusside anions (NP)into zinc and aluminium layered double hydroxides (LDHs). The materials were prepared by thecoprecipitation method under constant pH, followed by a hydrothermal treatment. Theprepared materials were characterised by a set of analysis methods, such as powderX-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry(TG), scanning electron microscopy (SEM) and cyclic voltammetry (CV). The resultsshowed that the electrochemical response of NP ions into LDH structure is similar to thatfound for complex ions free in solution. In addition, our results reveal the dependence ofthe electrochemical response on the nature of the supporting electrolyte, for either cationic oranionic species.  相似文献   

18.
Incorporation of heteroatoms into the framewo rk of zeolites has become a significant strategy to improve their performance in catalysis and adsorption,because the obtained heteroatom zeolites exhibit quite different properties from the conventional aluminosilicate zeolites in aspects of surface acidity,pore structures,particle size and so on.In this review,the progress on the heteroatom zeolites including their synthesis and application is highlighted.First,the recent advance on the design and synthesis of different heteroatom zeolites is summarized.Special emphasis is placed on the introduction and comparison of three typical methods,including the direct synthesis,post synthesis and improved direct synthesis,for the traditional heteroatom zeolites(such as TS-1,Sn-MFI,Sn-β) and newly-reported heteroatom zeolites(such as W-MFI,Mo-MFI).According to their intrinsic characteristics,the application of heteroatom zeolites in diverse fields,such as production of fine chemicals,air pollution control and biomass conversion is then discussed.Finally,the challenges and perspective on the future development of heteroatom zeolites in low-cost preparation and practical application are proposed.  相似文献   

19.
催化不对称Michalel加成反应的新进展   总被引:5,自引:0,他引:5  
杜大明  花文廷 《有机化学》2002,22(3):164-173
总结了近年催化不对称Michael加成反应的新方法,包括手性金属络合物催化 的反应,呈手性Lewis酸性的手性金属络合物促进的不对称加成,手性冠醚络合物 催化的反应及其它催化反应。  相似文献   

20.
丙二腈类衍生物在农药方面良好的除草、杀菌、杀虫等生物活性得到了深入研究,在医药、染料等方面的用途也有报道;丙二腈双氰基强吸电子性的特点,导致亚甲基上两个氢都很活泼,容易发生取代、加成、缩合、消去等反应。依据丙二腈氰基α位取代基的结构特点将丙二腈衍生物分三类进行归纳:α位为单键的丙二腈衍生物、α位为双键的丙二腈衍生物、α位为环状结构的丙二腈衍生物,同时介绍了丙二腈类衍生物应用及合成研究进展。  相似文献   

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