The Effect of Rare Earth on the Activity of Methanol Synthesis Catalyst

In this paper several rare earth oxides were added into methanol synthesis catalyst by solid-mixing method to improve the activity of methanol synthesis catalyst. Nd2O3, CeO2, La2O3 and Sm2O3 decrease the catalyst activity, while Pr2O3, Gd2O3 and Eu2O3 increase the methanol yield.

Highly active catalyst for vinyl acetate synthesis by modified activated carbon

A new zinc acetate catalyst which was prepared from modified activated carbon exhibited extreme activity towards the synthesis of vinyl acetate. The activated carbon was modified by nitric acid, vitriol and peroxyacetic acid （PAA）. The effect on specific area, structure, pH and surface acidity groups of carders by modification was discussed. Amount of carbonyl and carboxyl groups in activated carbon was increased by peroxyacetic acid treatment. The productivity of the new catalyst was 14.58% higher than that of catalyst prepared using untreated activated carbon. The relationship between amount of carbonyl and carboxyl groups （m） and catalyst productivity （P） was P = 1.83 ＋ 2.26 × 10^-3＊e^3.17m. Reaction mechanism was proposed. C 2009 Liang Rong Feng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Fabrication of K-promoted iron/carbon nanotubes composite catalysts for the Fischer–Tropsch synthesis of lower olefins

K-promoted iron/carbon nanotubes composite（i.e., Fe K-OX） was prepared by a redox reaction between carbon nanotubes and K2FeO4followed by thermal treatments on a purpose as the Fischer–Tropsch catalyst for the direct conversion of syngas to lower olefins. Its catalytic behaviors were compared with those of the other two Fe-IM and Fe K-IM catalysts prepared by impregnation method followed by thermal treatments. The novel Fe K-OX composite catalyst is found to exhibit higher hydrocarbon selectivity,lower olefins selectivity and chain growth probability as well as better stability. The catalyst structureperformance relationship has been established using multiple techniques including XRD, Raman, TEM and EDS elemental mapping. In addition, effects of additional potassium into the Fe K-OX composite catalyst on the FTO performance were also investigated and discussed. Additional potassium promoters further endow the catalysts with higher yield of lower olefins. These results demonstrated that the introduction method of promoters and iron species plays a crucial role in the design and fabrication of highly active,selective and stable iron-based composite catalysts for the FTO reaction.

Catalytic kinetics of dimethyl ether one-step synthesis over CeO_2–CaO–Pd/HZSM-5 catalyst in sulfur-containing syngas process

CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of CeO_2–CaO–Pd/HZSM-5 was investigated to ensure that the kinetics experimental results were not significantly influenced by induction period and catalytic deactivation. A large number of kinetic data points(40 sets) were obtained over a range of temperature(240–300 °C), pressure(3–4 MPa), gas hourly space velocity(GHSV)(2000–3000 L·kg^(-1)·h^(-1)) and H_2/CO mole ratio(2–3). Kinetic model for the methanol synthesis reaction and the dehydration of methanol were obtained separately according to reaction mechanism and Langmuir–Hinshelwood mechanism. Regression parameters were investigated by the method combining the simplex method and Runge–Kutta method. The model calculations were in appropriate accordance with the experimental data.

RAMAN SPECTRA OF HYDROGEN ADSPECIES ON AMMONIA SYNTHESIS IRON CATALYST

Raman peaks at 1951 and 2165 cm^(-1) can be confirmed further by H_2/D_2 isotope exchange as H-adspecies on the doubly promoted iron catalyst for ammonia synthesis and are probably ascribed to two terminally adsorbed H-species.

SYNTHESIS OF ALLANTOIN USING HETEROPOLY COMPOUNDS AS CATALYSTS

Allantoin was synthesized with the yield as high as 68.5% using H3PW12O40. xH(2)O as catalyst. Optimum conditions for the synthesis were determined. It. was found that the heteropoly compound has higher catalytic activity than conventional inorganic acid catalysts (such as hydrochloric acid, etc.)

SYNTHESIS OF A KETAL BY USING HPA AS CATALYST

The work herein reported is about a rapid and convenient synthetic method of a betal formed from ethylene glycol and cyclohexanone by using H3PW12O40(HPA)as catalyst. It has ben shown that the reaction, by using HPA as catalyst, can proceed at room temperature and have the high yield of 92% and the catalyst can be used again and again

THE STUDYOF SYNTHESIS AND CHARACTERISTICS OF POLYPHENYLACETYLENE USING WOBr_4AS CATALYST

A new kind of catalyst WOBr_4,which can be used in the polymerization of phenylacetylene(PhA),has been synthesized.The obtained polyphenylcetylene(PPhA) using WOBr_4 as catalyst is soluble、fusible、with brown-red colour and has 1831(M n).The analysis of the stucture of PPhA shows that the polymer has cis-transoidal structure,therefore,the reaction mechanism is via complex catalysis.

NC310 Catalyst for Methanol Synthesis Developed by SINOPEC Research Institute of Nanjing Chemical Company

The NC310 type catalyst for methanol synthesis developedby the SINOPEC Research Institute of NanjingChemical Company has passed the appraisal of researchachievements organized by the Science and TechnologyDivision of the Sinopec Corp. The group of specialistsattending the appraisal meeting has recognized that thiscatalyst has reached the internationally advanced level interms of its overall catalytic performance.

SYNTHESIS OF FUNCTIONAL UNSATURATED POLYESTER BY USING RARE EARTH CATALYSTS 2.TERPOLYMERIZATION OF EPICHLOROHYDRINMALEIC ANHYDRIDE-CARBON DIOXIDE WITH Y(P_(204))_3-Al(i-Bu)_3

Teroolymerization of enichlorohydrin（ECH）-maleic anhydride（MAn）-carbon dioxide（CO;） was carried out by using Y(P;);-Al（i-Bu）;as catalyst for the first time.The terpolymersobtained were characterized by IR and;H-NMR.It was foundthat the composition of the teroolymer was influenced by theaddition mode,initial monomer charge ratio,etc.

A review of significant factors in the synthesis of hetero-structured dumbbell-like nanoparticles

This paper reviews several important factors that influence the synthesis of dumbbell‐like nanoparticles,which can significantly enhance the catalyst activity in catalytic combustion. The dumbbell‐like nanoparticles discussed in this article refer to a hetero‐structure with two nanoparticles of different materials in contact with each other. This nanostructure can be considered as a special intermediate between individual spherical nanoparticles and a core–shell nanostructure. Therefore,the synthesis of dumbbell‐like nanoparticles is more difficult than other structures. The controllability of the synthesis process, the nanoparticle size and size distribution, and the morphology of the final products depend on many factors： the seed size and size ratio could be used to influence the controllability of epitaxial growth. The component sizes and size distribution could be varied by carefully controlling the reaction temperature and reaction time. The morphology of the dumbbell‐like nanoparticles is closely related to the solvent polarity, the precursor ratio, the lattice mismatch between the two components, and the surfactant concentration. Some related synthesis methods are also briefly introduced in each section to facilitate understanding. This summary will benefit the development of new dumbbell‐like nanoparticles with various components, which have great potential in catalytic combustion of more dysoxidizable gases.

Catalytic Removal of PM by Li-Co Delafossite Catalysts

By using solution combustion synthesis method, several Li-Co delafossite catalysts were prepared via a highly exothermic and self-sustaining reaction. The prepared catalysts were characterized by XRD, SEM and the catalytic activities of the catalysts were evaluated by small sample experiment. It is shown that under loose contact conditions this catalyst can catalyze soot combustion at 360 ℃, and the best prepared catalyst Li Co0.9O2 can ignite soot combustion below 300 ℃. In the incompletely synthesized catalysts the Co cations shift to higher electrovalence, so the number of the surface adsorbed oxygen（O-） of the prepared delafossite catalysts increase and Li Co0.9O2 has the optimum catalytic activity.

Effect of alkali metals on the performance of CoCu/TiO_2 catalysts for CO_2 hydrogenation to long-chain hydrocarbons

CoCu/TiO_2 catalysts promoted using alkali metals（Li, Na, K, Rb, and Cs） were prepared by the homogeneous deposition-precipitation method followed by the incipient wetness impregnation method. The influences of the alkali metals on the physicochemical properties of the CoCu/TiO_2 catalysts and the catalytic performance for CO_2 hydrogenation to long-chain hydrocarbons（C_（5＋））were investigated in this work. According to the characterization of the catalysts based on X-ray photoelectron spectroscopy, X-ray diffraction, CO_2 temperature-programmed desorption（TPD）, and H_2-TPD, the introduction of alkali metals could increase the CO_2 adsorption and decrease the H_2 chemisorption, which could suppress the formation of CH_4, enhance the production of C_（5＋）, and decrease the hydrogenation activity. Among all the promoters, the Na-modified CoCu/TiO_2 catalyst provided the maximum C_（5＋） yield of 5.4%, with a CO_2 conversion of 18.4% and C_（5＋） selectivity of42.1%, because it showed the strongest basicity and a slight decrease in the amount of H_2 desorption;it also exhibited excellent catalytic stability of more than 200 h.

Effect of Cu-ZnO-Al_2O_3 supported on H-ferrierite on hydrocarbons formation from CO hydrogenation

Methanol synthesis catalysts based on Cu, Zn and Al were prepared by three methods and subsequently mixed with H-ferrierite zeolite in an aqueous suspension to disperse the catalysts over the support. These materials were characterized by X-ray diffraction, N2 adsorption, transmission electron microscopy, temperature programmed reduction, NH3 and H2 temperature-programmed desorption, and X-ray photoelectron spectroscopy. They were also applied to the CO hydrogenation reaction to produce dimethyl ether and hydrocarbons. The catalysts were prepared by coprecipitation under low and high supersaturation conditions and by a homogeneous precipitation method. The preparation technique was found to affect the precursor structural characteristics, such as purity and crystallinity, as well as the particle size distribution of the resulting catalyst. Low supersaturation conditions favored high dispersion of the Cu species, increasing the methanol synthesis catalyst＇s metallic surface area and resulting in a homogeneous particle size distribution. These effects in turn were found to modify the zeolite properties, promoting both a low micropore volume and blockage of the zeolite acid sites. The effect of the methanol synthesis catalyst on the reaction was verified by the correlation between the Cu surface area and the CO conversion rate.

MAF固体碱催化剂催化合成丙二醇甲醚

研究了甲醇与环氧丙烷在固体碱催化剂MAF存在下非均相合成丙二醇甲醚的过程。在反应温度为120～130℃、催化剂用量(质量分数)为0.20%～0.30%、甲醇与环氧丙烷摩尔比为3/1～5/1的反应条件下,环氧丙烷的转化率在98％以上,丙二醇甲醚的选择性达95％,收率达93％,产品中伯醚的选择性为92％～93％。实验发现,该固体碱催化剂使用后无须任何处理,可重复使用,是一种稳定性好、选择性高的环境友好催化剂。

吸热燃料裂解催化剂CuAPSO-34的合成及性能

采用Cu离子对硅磷酸铝分子筛SAPO 34进行离子改性 ,成功合成出CuAPSO 34分子筛。通过XRD ,SEM ,EDX及NH3 TPD等分析手段对改性分子筛进行结构及酸性的表征和对照分析 ,表明Cu的掺入较好改变了SAPO 34分子筛的微观结构及表面酸性。通过对吸热燃料模型化合物———正庚烷进行催化裂解的对比试验 ,获得了转化率和低碳烯烃的收率数据。结果表明CuAPSO 34能明显提高催化活性 ,大幅降低裂解温度 ;且在经济裂解温度区间 5 0 0℃～ 6 0 0℃对低碳烯烃的选择性亦有所提高 ,因而吸热燃料能够提供更高的热沉。

Highlights of the major progress in single-atom catalysis in 2015 and 2016

The idea that single metal atoms dispersed on a solid support can act as an efficient heterogeneous catalyst was raised in2011when single Pt atoms on an FeOx surface were reported to be active for CO oxidation and preferential oxidation of CO in H2.The last six years have witnessed tremendous progress in the field of single‐atom catalysis.Here we introduce the major achievements on this topic in2015and2016.Some particular aspects of single‐atom catalysis are discussed in depth,including new approaches in single‐atom catalyst(SAC)synthesis,stable gold SACs for various reactions,the high selectivity of Pt and Pd SACs in hydrogenation,and the superior performance of non‐noble metal SACs in electrochemistry.These accomplishments will encourage more efforts by researchers to achieve the controllable fabrication of SACs and explore their potential applications.

Microwave-assisted efficient synthesis of azlactone derivatives using 2-aminopyridine-functionalized sphere SiO_2 nanoparticles as a reusable heterogeneous catalyst

In the present work, the highly efficient Erlenmeyer synthesis of azlactones catalyzed by 2- aminopyridine, supported on nano-sphere Si02 is reported. First, the silica nanoparticles were modified with triethoxysilylpropyl chloride and then 2-aminopyridine was attached to the support via covalent linkages. This new heterogenized catalyst was used for efficient microwave-assisted synthesis of azlactone derivatives with Ac20 as a condensing agent under solvent-free conditions. The present method offers advantages including high yields, short reaction times and simple work-up. Also, the catalyst can be easily recycled and reused several times, which makes this method attractive, economic and environmentally-benign.

Nested Metal Catalysts:Metal Atoms and Clusters Stabilized by Confinement with Accessibility on Supports

Supported catalysts that are important in technology prominently include atomically dispersed metals and metal clusters.When the metals are noble,they are typically unstablesusceptible to sinteringespecially under reducing conditions.Embedding the metals in supports such as organic polymers,metal oxides,and zeolites confers stability on the metals but at the cost of catalytic activity associated with the lack of accessibility of metal bonding sites to reactants.An approach to stabilizing noble metal catalysts while maintaining their accessibility involves anchoring them in molecular-scale nests that are in or on supports.The nests include zeolite pore mouths,zeolite surface cups(half-cages),raft-like islands of oxophilic metals bonded to metal oxide supports,clusters of non-noble metals(e.g.,hosting noble metals as single-atom alloys),and nanoscale metal oxide islands that selectively bond to the catalytic metals,isolating them from the support.These examples illustrate a trend toward precision in the synthesis of solid catalysts,and the latter two classes of nested catalysts offer realistic prospects for economical large-scale application.

Kinetic studies of methanol synthesis from CO_2+H_2 over copper based catalysts

The catalytic activity for the synthesis of methanol from carbon dioxide and hydrogen was measured on various binary and ternary catalysts containing copper oxide under a pressure of 10 atm. Among these samples the catalysts, CuO/ZnO/γ-Al_2O_3, demonstrated the highest activity and selectivity to methanol; MnO, as third component, had no promotional effect on the activity of meth- anol formation. Based on a simple power rate law the apparent activation energy estimation and par- tial pressure dependence measurement were accomplished over eight catalysts. The activation energies varied from 40 to 120 kJ / mol depending on the composition of catalysts. The rates of methanol for- mation to be 0.3 -- 0.9 order in H_2 and about 0.1 -- 0.2 order in CO_2 were reported.