NOx选择催化还原用Au/海泡石催化剂的研究

以天然海泡石为原料,对其进行酸改性后作为催化剂载体。采用浸渍法制备了用于CO选择催化还原NOx的负载型Au/海泡石催化剂。设计正交实验对海泡石酸改性条件进行了研究,对催化剂催化还原NOx的活性进行了评价。实验结果表明,该催化剂对于NOx催化还原反应有一定活性。对酸改性前后的海泡石及制得的催化剂进行了TGA、IR和XRD分析,证实海泡石是一种较好的催化剂载体。     

海泡石及其在FCC催化剂中的应用

综述了海泡石热相变研究的现状、活化改性的主要方法及在催化剂中的应用,展望了改性海泡石在FCC催化剂中的应用前景。探索了改性海泡石作为FCC催化剂基质的可行性。结果表明,改性海泡石作为FCC催化剂基质,可以有效提高催化剂的比表面积、孔容以及中孔孔容,能够加强催化剂的抗重金属作用,显示出优良的催化性能,具有良好的应用前景。     

海泡石的改性及其在催化中的应用

海泡石具有巨大的比表面和独特的孔结构, 而且资源丰富, 价格低廉, 是一种新型的催化材料。本文叙述了海泡石的改性方法及其在催化中的应用, 评述了它的研究进展和发展动向。     

海泡石改性及其在含铬废水处理中的应用

海泡石资源丰富,廉价易得,被广泛用于各类废水的处理.详细综述了海泡石的改性方法、改性条件及其特点,介绍了海泡石及改性海泡石在含铬废水处理中的应用,总结海泡石吸附剂的再生方法.指出海泡石及改性海泡石在含铬废水处理方面需要对吸附去除机理和吸附剂的再生方面深入研究.     

海泡石的改性方法及其应用研究进展

综述了海泡石的存在形式、分布范围以及海泡石的改性方法(热处理、酸改性、表面活性剂改性、偶联剂改性以及聚合物包覆等改性)及在吸附、催化、阻燃、调湿、建筑和摩擦等方面应用领域的研究进展。通过改性研究使得海泡石的应用范围更加广泛,但将海泡石用作增强型硅酸盐水凝胶、吸波、超级电容器等方面的研究比较空白;此外,随着经济社会的快速发展,人类生活质量的提高和环保意识的增强,对材料性能和环保性能也造成了一定的挑战,故而实现海泡石对环境以及健康的无毒性以及多样化应用,即满足不同领域生产和生活需求,将会是未来海泡石发展的方向。     

海泡石载体催化剂的研究进展

海泡石是一种具有天然吸附性、流变性及催化性的含水硅酸盐矿物。对海泡石的结构、成分做了相关介绍。重点综述了对其进行改性及负载的方法以及其在催化领域的最新的研究应用进展及趋势。     

海泡石的改性方法及其应用研究进展

综述了海泡石的存在形式、分布范围以及海泡石的改性方法(热处理、酸改性、表面活性剂改性、偶联剂改性以及聚合物包覆等改性)及在吸附、催化、阻燃、调湿、建筑和摩擦等方面应用领域的研究进展。通过改性研究使得海泡石的应用范围更加广泛,但将海泡石用作增强型硅酸盐水凝胶、吸波、超级电容器等方面的研究比较空白;此外,随着经济社会的快速发展,人类生活质量的提高和环保意识的增强,对材料性能和环保性能也造成了一定的挑战,故而实现海泡石对环境以及健康的无毒性以及多样化应用,即满足不同领域生产和生活需求,将会是未来海泡石发展的方向。     

有机海泡石的制备及其结构性能的研究

以十六烷基三甲基溴化铵(CTMAB)为改性剂,采用机械化学改性工艺对江西乐平天然海泡石进行有机改性.运用正交实验,优化出海泡石改性的最佳工艺参数.通过BET、XRD、FT-IR和TEM的测试手段对改性海泡石进行了结构表征,研究表明,海泡石改性后纯度得到提高,其比表面积为410m2/g,是原矿的4.5倍;改性样品的红外图谱表明有机改性剂(CTMAB)进入了海泡石晶体层间,引起了晶层间距的增大,从而提高了海泡石的吸附活性.TEM表明,改性海泡石的形貌呈纤维束状集合体,结构较疏松,纤维束较分散,并保持了晶体结构形态.     

改性海泡石对亚甲基蓝的吸附性能

对海泡石进行了硫酸改性、高温改性、硫酸/高温改性,以亚甲基蓝为吸附对象,研究了改性方法对海泡石吸附性能的影响,对各改性海泡石进行了孔径、孔体积等表征. 结果表明,3种改性方法中,硫酸/高温改性对海泡石吸附性能的提高效果最好,吸附量比改性前提高47.8%,达41 mg/g,吸附等温线符合Langmuir方程. 硫酸/高温复合改性后的海泡石平均孔径达9.74 nm,孔体积达7.064′10-2 cm3/g,分别提高117%和92.6%. 对改性海泡石对亚甲基兰的吸附机理进行了探讨.     

海泡石的有机化改性及其对曙红Y的吸附行为研究

分别采用阴阳离子表面活性剂对海泡石进行有机化改性处理,以有机化改性海泡石和原生海泡石为吸附剂,研究其对曙红Y的吸附性能及影响因素.结果表明,经CTMAB改性的海泡石对水中曙红Y的极限吸附量比经DOSO3Na改性过的海泡石及原生海泡石对曙红Y的极限吸附量高出103倍.     

过渡金属对Ru/海泡石催化剂加氢性能及表面性质的影响

用浸渍法制备了一系列含不同助剂Mo、Co、Mn、Cu、Zr等的Ru/海泡石催化剂，以CO₂及苯加氢为探针反应，以TPD和CS₂中毒为手段研究了助剂对Ru/海泡石催化剂加氢、反应物吸附及活化性能的影响。结果表明，助剂的加入显著地影响Ru/海泡石催化剂的催化活性，且随着反应分子的加大，这种影响随之增大；助剂对催化反应中反应物的吸附、活化过程的影响是其影响催化活性的重要原因。另外，结果还表明，助剂的加入还调整了Ru/海泡石催化剂的表面性能，但并没有改变活性中心的类型。     

Cu/海泡石——新型NO还原催化剂

以改性海泡石为载体,用液相浸渍法负载Cu,制备用于富氧条件下CO还原NO的催化剂.海泡石的改性条件由正交实验方法确定.考察了反应气体中氧含量和空速条件等对Cu/海泡石催化剂性能的影响,并用XRD、TGA、H2-TPR、BET等对该催化剂进行表征.研究表明,灼烧温度为400 ℃、负载量为5%（质量）的Cu/海泡石催化剂对NO还原有较高的活性.Ce 和 Sm 的加入可以明显改善Cu/海泡石催化剂的性能.在实验条件基本相同的情况下,Cu/海泡石的催化活性好于Cu/ZSM-5催化剂.     

Catalytic properties of aluminated sepiolite in ethanol conversion

The aluminated sepiolite, obtained by alkaline treatment with KAlO₂, as well as the silver-exchanged aluminated sepiolite were tested in ethanol conversion. The reactions were performed at 280°C and with 50 Torr of ethanol in He. After the alumination through KA1O₂, ethanol dehydrogenation and ethanol dehydration resulted from the Lewis acidity. The dispersion of silver led to a bifunctional catalytic system and the overall catalytic activity and the selectivity towards the acetaldehyde production increased. As a result of the Prins reaction, a significant yield in butadiene was observed.     

A novel and facile impregnation-combustion fabrication of spherical CoAl2O4 supported on sepiolite nanofibers

In this study, sepiolite nanofibers-supported spherical CoAl₂O₄ composites were prepared by a novel and facile impregnation-combustion method, using nitrates and sepiolite minerals as the raw materials. The results showed that the optimal process for the nanocomposites formation was an impregnation step facilitated by stirring for 24?h at room temperature coupled with a calcination step performed at 300?℃ for 6?h. The characterizations by XRD, SEM and BET revealed that the CoAl₂O₄ particles were dispersed evenly on the surface of the sepiolite nanofibers with a complete crystal shape and uniform particle size, and the specific surface area has been improved significantly by adopting the sepiolite nanofibers as the support. Therefore, the sepiolite nanofibers-supported spherical CoAl₂O₄ composites with a good dispersion and suspension performance are a promising candidate in the fields of water-based coatings, heterogeneous catalytic reactions, ceramic materials, and so on.     

Preparation of mesoporous MCM-41 from natural sepiolite and its catalytic activity of cracking waste polystyrene plastics

Mesoporous MCM-41 was prepared by leaching of sepiolite and sequent hydrothermal synthesis in NaOH solution with hexadecyltrimethylammonium bromide as template. Small-angle X-ray diffraction patterns, Scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller were performed to characterize the resulting compounds. The results showed that the crystallinity and pore size of MCM-41 increased with increase of crystallization time, ratios of surfactant to SiO₂ and decrease of Mg content. The experimental results of catalytic cracking of polystyrene waste showed that the MCM-41 with MgO from natural sepiolite had high catalytic activity and good selectivity to monomer styrene for the catalytic cracking of polystyrene when the ratio of waste plastics to MCM-41 was 200. The side reactions yielded ethylbenzene, isopropylbenzene, isopropenylbenzene and secondary cross-linking were suppressed by basic species MgO in MCM-41.     

海泡石和稀土对镍催化剂性能的影响

本文研究了海泡石和稀土Sm镍催化剂的苯加氢活性及CO_２甲烷化活性的影响，并用XPS、活性比表面积及CS_２中毒等方法表征了催化剂的表面性质。结果表明，海泡石和稀土Sm能提高镍催化剂的加氢活性和抗毒性，并能增大活性镍的比表面及镍上的电子云密度，降低CO_２甲烷化反应的活化能。     

Gas-phase selective oxidation of toluene on TiO2–sepiolite supported vanadium oxides: Influence of vanadium loading on conversion and product selectivities

Gas-phase selective oxidation of toluene has been carried out on vanadium oxide systems (5–20 wt.% of V₂O₅, equivalent to 0.4–1.7 theoretical monolayers) supported on TiO₂–sepiolite (with titania loading around the theoretical monolayer, 12 wt.%) and on sepiolite. A study has been made on both the influence of vanadia loading and of the support on the catalytic behaviour of the supported vanadium systems. The reducibility by H₂ TPR was also studied as well as the acid and basic/redox sites from the results of conversion of the 2-propanol test reaction of the solids. Benzaldehyde, benzoic acid and several coupling products were the main ones detected, attaining over 50% selectivity towards the benzaldehyde and benzoic acid products at a total conversion around 10%. The activity and selectivity to the selective products exhibited by vanadium systems supported on mixed support were superior to those exhibited by the systems supported on sepiolite and increased notably in both series with the increase in vanadium loading. The best catalytic behaviour exhibited by the vanadium systems supported on mixed support, which also exhibited the highest density of sites capable of being reduced (as well as their reducibility) and of those responsible for propanone formation, could be attributed not only to the different balance of the vanadia species existing in the two supports (monomeric + oligomeric/polymeric), but also to such other factors as the nature of the support and, concretely, its chemical composition.