PREPARATION OF CUO/γ-Al2O3 CATALYSTS FOR CATALYTIC COMBUSTION VOCS VIA PLASMA

CuO/γ-Al2O3 catalysts were prepared by plasma treatment and conventional impregnation methods. The catalytic combustion of two kinds of volatile organic compounds (VOCs), toluene and benzene, were carried out over these CuO/γ-Al2O3 catalysts. The surface properties of these catalysts were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The experimental results showed that in catalytic combustion the activity of the CuO/γ-Al2O3 catalyst prepared via plasma was much higher than that of the CuO/γ-Al2O3 catalyst prepared by conventional impregnation method. XRD results showed that an enhanced dispersion had been achieved with the plasma treatment. SEM results indicated that the size became much smaller and the surface became more uniform with the plasma treatment.     

CATALYTIC PERFORMANCE OF DIFFERENT CATALYSTS FOR NO_xREDUCTION UNDER O_2-CONTAINING CONDITION

ＣＡＴＡＬＹＴＩＣＰＥＲＦＯＲＭＡＮＣＥＯＦＤＩＦＦＥＲＥＮＴＣＡＴＡＬＹＳＴＳＦＯＲＮＯｘＲＥＤＵＣＴＩＯＮＵＮＤＥＲＯ２ＣＯＮＴＡＩＮＩＮＧＣＯＮＤＩＴＩＯＮＬｉＳｈｉｙａｏ，ＷｕＣｈｕｎｔｉａｎ，ＣｈｅｎｇＨｕｉｗｅｎ，ＬｉＨｅｎｇｑｉａｎｇ...     

MICROCALORIMETRIC AND DEHYDROGENATION ACTIVITY STUDIES OF Pt/γ-Al_2O_3 AND Pt-Sn/γ-Al_2O_3 CATALYSTS

ＭＩＣＲＯＣＡＬＯＲＩＭＥＴＲＩＣＡＮＤＤＥＨＹＤＲＯＧＥＮＡＴＩＯＮＡＣＴＩＶＩＴＹＳＴＵＤＩＥＳＯＦＰｔ／γ┐Ａｌ２Ｏ３ＡＮＤＰｔ┐Ｓｎ／γ┐Ａｌ２Ｏ３ＣＡＴＡＬＹＳＴＳ＊ＪｉａＪｉｆｅｉ１，ＳｈｅｎＪｉａｎｙｉ２，ＸｕＺｈｕｓｈｅｎｇ１，ＧｅＸ...     

Co/γ-Al_2O_3 CATALYSTS FOR NITRIC OXIDE SELECTIVE REDUCTION BY ETHYLENE

采用等量浸渍法制备了Ｃｏ／γＡｌ２Ｏ３催化剂，考察了它们对乙烯选择还原ＮＯ的反应性能，用ＸＲＤ和ＢＥＴ方法表征了催化剂．结果表明，在Ｃｏ／γＡｌ２Ｏ３中存在两种钴相，即Ｃｏ３Ｏ４和ＣｏＡｌ２Ｏ４，前者是Ｃ２Ｈ４的完全氧化活性中心，后者是ＮＯ的选择性还原活性中心．随焙烧温度的提高，Ｃｏ３Ｏ４向ＣｏＡｌ２Ｏ４相的转化是样品对Ｃ２Ｈ４完全氧化活性下降和对ＮＯ选择还原活性升高的主要原因．更高焙烧温度下，样品活性的下降与载体及ＣｏＡｌ２Ｏ４相的烧结有关．     

OXIDATIVE COUPLING OF METHANE OVER Sr-Pb-O AND Sr-Pb-O/γ-Al_2O_3 CATALYSTS

Two series of Sr-Pb-O and Sr-Pb-O/γ-Al_2O_3 catalysts of differentcomposition were investigated for the oxidative coupling of methane.Theeffects of reaction conditions on the catalytic behavior have been studied.Catalyst characterization was carried out by XRD,TPR,TPD and XPS tech-niques.It was found that a strong interaction took place between Sr-Pb-Oand γ-Al_2O_3 so that Sr_3Al_(32)O_(51)phase and a small amount of PbAl_2O_4 formedin the bulk and the surface was mainly enriched with Pb.A 30 wt% Sr-Pb-O/γ-Al_2O_3 catalyst gave a 30.4% methane conversion and a 50% C_2 selec-tivity at 750℃ and with a feed gas composition of CH_4:O_2=2.5:1.Theenrichment of Pb on the surface may be responsible for the higher catalyticactivity and selectivity.     

ACTIVATION OF O_2 AND CATALYTIC PROPERTIES OF CeO_2/CaF_2 CATALYSTS FOR METHANE OXIDATIVE COUPLING

The investigation of the catalytic properties of the CaF_2 modifiedCeO_2 catalysts for the methane oxidative coupling (MOC) to prepare C_2 hydro-carbons indicated that most of the CaF_2 modified CeO_2 catalysts were efficientfor the MOC reaction. Addition of CaF_2 to CeO_2 can make the C_2 selectivity in-crease from 2. 2％ (over CeO_2) to 46-63％, and the CH_4 conversion increasefrom 26％ to 28-30％. When the CeO_2 content was decreased within a defi-nite region, the activity and C_2 selectivity of the catalysts increased remark-ably. The XRD characterization revealed that F~-—O~(2-)exchange happened be-tween CaF_2 and CeO_2 phases. TPD, XPS, Raman and ESR experiments indicat-ed that O~-, O_2~(2-) and O_2~-species were formed over CeO_2/CaF_2 catalysts. Withthe increase of CaF_2 content in the catalysts, the kinds and the surface concen-trations of the above mentioned oxygen species decreased, while the C_2 selectivi-ty increased.     

CATALYTIC BEHAVIOR OF DOPED MTiO_3 CATALYSTS FOR OXIDATIVE DEHYDROGENATION OF ETHANE

用Ｌｉ＋部分替代ＭＴｉＯ３（Ｍ＝Ｃａ、Ｓｒ）催化剂中的Ｔｉ４＋，明显地提高了乙烷氧化脱氢（ＯＤＨＥ）反应中乙烯的选择性。在ＣａＴｉ０．９Ｌｉ０．１Ｏ３－δ催化剂上，反应温度为８５０℃时，乙烯选择性为７７．４％，乙烷转化率为８１．７％。Ｌｉ掺杂的作用是增加了催化剂的Ｐ型半导性和未充分还原的氧物种数目。     

IONIC CONDUCTIVITY AND CATALYTIC PERFORMANCE OF A_2BO_4/La_2O_3 CATALYSTS FOR OXIDATIVE COUPLING OF METHANE

A series of La_2O_3 cartalysts modified by A_2BO_4 compounds with supe-rionic conductivity were prepared. It was observed that the addition of A_2BO_4compounds to La_2O_3 enhances C_2 yields, and the C_2 yields over the modified cat-alysts are intimately related with their conductivities. The effects of A_2BO_4compounds on the conductivity and catalytic performance were discussed. Onlywhen ion A has high conductivity, can the catalyst show good catalytic perfor-mance. A mechanism for interpreting the significant effects of alkali metals wasproposed.     

XPS IN VESTIGATION OF γ-Al_2O_3 SUPPORTED Pt-CONTAINING DUAL-COMPONENT CATALYSTS

ＸＰＳＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦγ┐Ａｌ２Ｏ３ＳＵＰＰＯＲＴＥＤＰｔ┐ＣＯＮＴＡＩＮＩＮＧＤＵＡＬ┐ＣＯＭＰＯＮＥＮＴＣＡＴＡＬＹＳＴＳ＊ＪｉａＪｉｆｅｉ１，ＫｏｕＹｕａｎ２，ＸｕＺｈｕｓｈｅｎｇ１，ＺｈａｎｇＴａｏ１，ＺｈａｎｇＢｉｎｇ２，Ｌｉ...     

ADSORPTION AND ACTIVATION OF CARBON MONOXIDE ON SULFIDED Co/Mo/γ-Al_2O_3 METHANATION CATALYSTS

Four different types of Co/Mo/γ-Al_2O_3 sulfided methanation cata-lysts containing promotors K,P,Mn and Ni respectively prepared by impregna-tion method have been carefully studied by means of in silu IR spectroscopy andXPS(X-ray photoelectron spectroscopy).Reactant carbon monoxide was tak-en as the probe molecule.From carbon monoxide absorption IR spectra,it wasfound that carbon monoxide adsorption is a reversible chemisorption process atdifferent temperatures.The activation degree of carbon-oxygen bond bychemisorption depends strongly on temperature.Promotors potassium,man-ganese,phosphorus and nickel show an electronic effect on Co/Mo/γ- Al_2O_3catalysts.Their promotion effects are in the order of CoMo-K(15)>CoMo-Mn(5)≈Ni(5)Mo>P(5)-CoMo.Prereduction or preoxidation of the sulfidedcatalysts resulted in loss of the characteristics of carbon monoxide IR band andmethanation activity as well.     

DECOMPOSITION OF KNO_3/γ-Al_2O_3 AND THE FORMATION OF SURFACE BASE SITES

ＤＥＣＯＭＰＯＳＩＴＩＯＮＯＦＫＮＯ３／γ┐Ａｌ２Ｏ３ＡＮＤＴＨＥＦＯＲＭＡＴＩＯＮＯＦＳＵＲＦＡＣＥＢＡＳＥＳＩＴＥＳ＊ＴｕＭａｉ，ＬｉＤａｔａｎｇ，ＺｈｕＪｉａｎｈｕａ，ＳｈｅｎＪｉａｎｙｉ＊＊（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｉｎｓ...     

APPLICATION OF N-DOPED CARBON NANOTUBES FOR THE PREPARATION OF HIGHLY DISPERSED PdO–CeO2 COMPOSITE CATALYSTS

Journal of Structural Chemistry - Pd–CeO2 catalytic composites deposited on the surface of carbon nanomaterials (CNMs) can act as model systems for probing the nature of active sites of...     

NiO在γ-Al_2O_3及 TiO_2/γ-Al_2O_3载体上的表面存在状态

本文采用 LRS, XRD, UV-DRS, TPR考查了γ-Al2O3上 TiO2的分散容量,分散态 Ti4＋离子的配位环境; NiO在经 TiO2改性后的γ-Al2O3载体上的分散容量。结果表明：（ 1） TiO2在γ-Al2O3表面的分散容量约为 0.62 mmol/100m2γ-Al2O3,当 TiO2含量低于该分散容量时 Ti4＋在γ-Al2O3载体表面以嵌入形式呈离子态分布;而含量高于分散容量时还有结晶态的 TiO2出现。（ 2） NiO在 TiO2/γ-Al2O3载体表面的分散容量约为 1.1 mmol/100m2γ-Al2O3,比之在γ-Al2O3载体表面的分散容量 (1.5mmol/100m2γ-Al2O3)要低,这是由于γ-Al2O3表面上部分空位被 Ti4＋离子占据。用表面相互作用的“嵌入模型” (Incorporation Model）讨论了这些结果。     

EFFECT OF THE THIRD COMPONENT ON THE CATALYTIC PROPERTIES OF Cu-Co CATALYSTS FOR ALCOHOL SYNTHESIS

The study of the effect of the third compunent on the catalytic prop-erties of Cu-Co catalysts for the selective synthesis of alcohols from CO andH_2 showed that addition of the third component influenced the reductivn proper-ty of Co which in turn would influence the activity and selectivity of catalystsfor alcohols synthesis.     

PREPARATION OF NOVEL POLYETHYLENE-graft-POLY(4-VINYLPYRIDINE)-SUPPORTED METALLOCENE CATALYSTS FOR ETHYLENE POLYMERIZATION

Polyethylene (PE) grafting 4-vinylpyridine copolymers has been produced as powders of different rushes by theirradiation method. After treatment with methylaluminoxane (MAO), the copolymers were used as supports for Cp_2ZrCl_2catalyst Results of X-ray photoelectron spectroscopy, Fourier transforms infrared spectroscopy, ultraviolet spectroscopy andscanning electron microscope measurements show that the catalytic sites have been linked through MAO on the PE-graft-4-vinylpyridine (PEVP). The percentages of grafting 4-vinylpyridine and supported Cp_2ZrCl_2 depend on the size ofpolyethylene powder. The smaller the polyethylene powder, the more percent of 4-vinylpyridine groups and Cp_2ZrCl_2 existon the polyethylene chains, and the PEVP-supported catalyst has a relatively high activity for ethylene polymerization.     

PREPARATION OF V_2O_3 BY THERMAL DECOMPOSITION OF HYDRAZINE-CONTAINING VANADIUM SALT

A new method of preparing V_2O_3 by thermal decomposition from hydrazine-containing vanadium salt was described. The process was investigated by thermal analysis (TG and DSC) and the thermally decomposed product was studied by S.E.M., chemical analysis and X-ray diffraction. The result indicated that the product obtained in this way was V_2O_3.     

PREPARATION OF POLYMER-SUPPORTED RCpCpTiCl_2 AND APPLICATION IN CATALYTIC ISOMERIZATION OF 1,5-HEXADIENE

Polymer-supported RCpCpTiCl2 (Cp =η5-C5H4; RCp = η5-RC5H4) have been prepared and reduced by i-C3H7MgBr in situ , then used in catalytic isomerization of1,5-hexadiene. The isomerization of 1, 5-hexadiene leads to a mixture of cyclic and linear products. The ratio of cyclic to linear product depends on the nature of the supporter and the substituent on the cyclopentadienyl ring. The former contributes themost, for example, silica supported Cp2TiCl2 gave cyclic-linear ratio of 99/1,while for polymer-supported Cp2TiCl2 species, linear compounds are the major products and the ratio of cyclic to linear product changes with different R groups on the cyclopentadienyl ring.     

PREPARATION OF La_2O_3 ULTRAFINE PARTICLE BY HOMOGENEOUS PRECIPITATION

Y_2O_3 ultrafine particles have been prepared by means of precipitation in Japan and U.S.A., and ultrafine particles of rare earth oxide have been prepared with dicarboxyl precipitate by Wang Zenglin et al. It has not been reported, however, to prepare La_2O_3 ultrafine particles with urea as the hydrolytic agent. This method is easy to operate, and the materials are cheap and easily available, besides, it is easy to obtain homogeneous spherical precursors of ultrafine particles. The present, paper describes the preparation of La_2O_3 ultrafine particles with urea as hydrolytic agent, and observes some of its characteristics.     

PREPARATION OF SPHERICAL， MONODISPERSED NANOMETER Eu_2O_3 PARTICLES

ＰＲＥＰＡＲＡＴＩＯＮＯＦＳＰＨＥＲＩＣＡＬ，ＭＯＮＯＤＩＳＰＥＲＳＥＤＮＡＮＯＭＥＴＥＲＥｕ_２Ｏ_３ＰＡＲＴＩＣＬＥＳ￥ＪｕｎＭＡ；ＱｉＪｉｅＹＡＮ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＮａｎｊｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｊｉｎｇ２１...