共查询到17条相似文献,搜索用时 93 毫秒
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固载超强酸催化剂制备及催化合成乙酸正丁酯的研究 总被引:14,自引:0,他引:14
研究了把稀土硫酸盐,分别固载于人工沸石、活性炭和强酸型阳离子树脂作为酯化催化剂,从中选出了较好的酯化催化剂-强酸型阳离子树脂固载稀土催化剂,此催化剂用于合成乙酸正丁酯,产率达到97.24%,并对催化剂的催化性能进行了讨论。 相似文献
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稀土氧化物超微粉的催化酯化行为 总被引:6,自引:0,他引:6
制备了5种稀土氧化物超微粉并考察了它们的催化酯化的活性,发现超微粉的催化活性均高于普通稀土氧化物,Y_2O_3超微粉催化酯化产物的酸值接近0.1,有应用前景。 相似文献
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稀土催化材料的制备、结构及催化性能 总被引:2,自引:0,他引:2
稀土催化材料的研究和发展为La和Ce等高丰度轻稀土元素的高质、高效利用提供了有效的途径.稀土元素具有未充满电子的4f轨道和镧系收缩等特征,作为催化剂的活性组分或载体使用时表现出独特的催化性能.本文从稀土氧化物、稀土复合氧化物、稀土-贵金属催化剂、稀土改性多孔催化材料等稀土催化材料出发,重点介绍和讨论了稀土的添加对催化剂的结构、活性和稳定性等的影响,阐述了稀土与过渡金属及氧化物、稀土与贵金属之间的相互作用,及对催化剂催化性能的影响.并对稀土催化材料的研究和发展提出了思考和展望. 相似文献
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负载稀土型酸活化膨润土的酯化催化活性 总被引:7,自引:0,他引:7
负载稀土型酸活化膨润土的酯化催化活性李永绣,冯天泽,胡平贵,何小彬,辜子英,廖荣辉(南昌大学化学系南昌330047)关键词稀土,膨润土,催化酯化可用稀土、膨润土单独作酯化催化剂,但活性不高[1~3]。本文将稀土用离子交换的方法负载到酸活化膨润土中,寻... 相似文献
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稀土氧化物作为酯化反应催化剂的改进 总被引:2,自引:0,他引:2
我们曾对14个稀土氧化物作为高沸点醇、酸的多相酯化反应催化剂进行过探索,本文报导采用高温分解稀土与1-苯基-3-甲基-4-苯甲酰基吡唑酮-5(HPMBP)配合物的方法可增大稀土氧化物的比表面,使其酯化催化活性有所提高。 相似文献
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研究了几种酸性催化剂(H2SO4、H3PO4、CH3C6H4SO3H)、碱性催化剂(NaOH、Na2CO3、NaHCO3)和氧化物(ZnO、Al2O3、TiO2)对山梨醇和油酸的催化酯化反应.结果表明用酸性催化剂催化的酯化反应产品中的双油酸酯的比例较高;用碱性催化剂或氧化物催化剂催化的酯化反应产品中的单油酸酯的比例较高,其中用ZnO催化所得产品中的单油酸酯的比例可达91%. 相似文献
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The construction of two-dimensional (2D) copper halide networks within a variety of perovskite hosts by a low-temperature topochemical method is demonstrated. Ion exchange between some layered perovskite oxides of the type A'[An - 1(M,M')nO3n + 1] (A' = alkali metal, H, NH4; A = alkaline earth, rare earth, or Bi; M,M' = Nb, Ta, Ti; n = 2, 3) with CuX2 (X = Cl, Br) results in the oxyhalides (CuX)[An - 1(M,M')nO3n + 1]. Rietveld refinements from X-ray powder diffraction data show that the structures of these new copper oxyhalides contain edge-sharing CuO2X4 octahedra sandwiched between the M/M'O6 octahedra of the perovskite slabs. The compounds are low-temperature phases that decompose well below 700 degrees C. The copper oxyhalides exhibit antiferromagnetic ordering resulting from the magnetic exchange interactions within the planar Cu-X networks. 相似文献
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以TiCl4为钛源合成钛硅分子筛 总被引:1,自引:0,他引:1
Since titanium silicalite-1 (TS-1) was first prepared by Taramasso et al[1] in 1983,the synthesis of TS-1 and its application in partial oxidation have become a hotspot in the zeolite catalytic field.For the traditional synthesis route of TS-1,the key problem is its costly price and severe synthesis conditions,which hamper its industrial application.To avoid using costly alkali-free tetrapropylammonium hydroxide (TPAOH) as a template,Müller et al[2] reported that TS-1 could be synthesized using tetrapropylammonium bromide (TPABr) as a template with ammonia as the base to adjust the basicity of the gel. 相似文献
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《Comptes Rendus Chimie》2016,19(10):1254-1265
Recent progress in catalytic direct NO decomposition is overviewed, focusing on metal oxide-based catalysts. Since the discovery of the Cu-ZSM-5 catalyst in the early 1990s, various kinds of catalytic materials such as perovskites, C-type cubic rare earth oxides, and alkaline earth based oxides have been reported to effectively catalyze direct NO decomposition. Although the activities of conventional catalysts are poor in the presence of coexisting O2 and CO2, some of the catalysts reviewed in this article possess significant tolerance toward these coexisting gases. The active sites for direct NO decomposition are different depending on the types of metal oxide-based catalysts. In the case of perovskite type oxides, oxide anion vacancies act as catalytically active sites on which NO molecules are adsorbed. C-type cubic rare earth oxides contain oxide anion vacancies with large cavity space, enabling easy access of NO molecules and their subsequent adsorption. Surface basic sites on alkaline earth based oxides participate in NO decomposition as active sites on which NO molecules are adsorbed as NO2− species. The reaction mechanisms of direct NO decomposition are also discussed. 相似文献
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SU Bao-Lian GUO Shen-DuChengdu Institute of Organic Chemistry Academia Sinica Chengdu. Sichuan 《天然气化学杂志》1995,(3)
The stability and the high temperature steam resistance of Ni/Al2O3 catalysis added with rare earth oxides were investigated. It was found that the addition of rare earth oxides resulted in great improvement in the stability and high temperature steam resistance of the catalysts through suppressing the growth of Ni crystallite, the oxidation of metal Ni and the formation of NiAl2O4. 相似文献
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Yaquan Wang Li Yang Tao Wang Zaiyi Zhang Gang Ruan Sen Han 《Reaction Kinetics and Catalysis Letters》1999,68(2):183-190
The effect of basic and rare earth metal oxides on the stability of nickel-based catalysts for the CO2 reforming of CH4 has been studied. The addition of metal oxides increased the stability of Ni-based catalysts and reversed the values of the
reaction orders with respect to both CH4 and CO2. In the presence of metal oxides, the values of the reaction orders with respect to CO2 partial pressure followed the same trend of catalyst stability. 相似文献
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The optical properties of rare earth ions in different inorganic host materials, for instance oxides, silicates, borates, or nitrides, have been used in applications for many years, from color TV to fluorescent tubes, lasers, or pc‐LEDs. However, rare earth metal ion‐doped hydrides have not really been considered as host lattices and up to now only been studied in a relatively small number of investigations. Yet, for certain metal hydrides these studies, e.g., allowed the determination of the crystal field strength and nephelauxetic effect of the hydride anion using the Eu2+ 5d excited state. In air‐sensitive hydrides, the use may be restricted to fundamental studies and local probes. But recently more and more air‐stable mixed anionic hydrides have been discovered, which may serve as hosts. This short review summarizes the synthesis and characterization of rare earth metal ion‐doped hydrides reported so far. 相似文献
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Cordierite honeycomb catalysts supported on rare earth (RE)-transition metal oxides, used for removing simultaneously three major pollutants, carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxides (NOx), in automotive emission have been investigated. The results indicate that the catalyst has improved three-way performance (TWP). 相似文献