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Chinese Journal of Polymer Science 2024年第4期42卷 501-510页

作者： Giovanni Ricci Anna Sommazzi Francesco Masi Alessandra Forni CNR-Istituto di Scienze e Tecnologie Molecolari“Giulio Natta”(SCITEC) via A.Corti 1220133MilanoItaly Viale Giovanni XXIII 34 I-28100NovaraNOItaly Via Galvani 7 I-26866Sant’Angelo LodigianoLOItaly CNR-Istituto di Scienze e Tecnologie Molecolari“Giulio Natta”(SCITEC) via C.Golgi 1920133MilanoItaly

Several novel cobalt dichloride complexes with amino-phosphine bidentate ligands were synthesized and characterized.For some of them single crystals were obtained and their molecular structure was determined by X-ray diffraction method.All the complexes were then used in combination with MAO for the polymerization of 1,3-butadiene,obtaining polymers with different structures(i.e.,predominantly 1,2 or cis-1,4)mainly depending on the type of ligand and on the MAO/Co molar ratio.The behavior of these novel catalysts was compared with that exhibited,in the polymerization of the same monomer,by the systems CoCl_(2)(PR3)2-MAO and CoCl_(2)(PRPh2)2-MAO(R=alkyl or cycloalkyl group),and by the systems based on cobalt dichloride complexes with various bi-and tridentate ligands(e.g.,diphosphines,bis-imines,pyridyl-imines,bis-iminopyridines).The comparison between the different systems allowed us to make some clarity about the actual and effective role played by the various types of ligands in the polymerization of conjugated dienes with catalytic systems CoCl_(2)(L)-MAO,in which L=mono-,bi-,or tri-dentate ligand.

关键词： 1,3-Butadiene Stereospecific polymerization cobalt catalysts Regioselectivity Aminophosphine ligands Crystal structures Chelate rings

Glycerol steam reforming over calcium hydroxyapatite supported cobalt and cobalt-cerium catalysts

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Journal of Energy Chemistry 2018年第2期27卷 404-412页

作者： J.Dobosz M.Cichy M.Zawadzki T.Borowiecki Institute of Low Temperature and Structure Research Department of Nanomaterials Chemistry and Catalysis Polish Academy of Sciences PO Box 1410 50-950 Wroclaw Poland Maria Curie-Sklodowska University Faculty of Chemistry Department of Chemical Technology 3 Maria Curie-Sklodowska Square 20-031 Lublin Poland

Calcium hydroxyapatite（HAp） supported cobalt and cobalt-cerium catalysts were examined for hydrogen production in glycerol steam reforming. The catalysts were synthesized by incipient wetness impregnation method and characterized through X-ray diffraction, adsorption-desorption isotherms of N2 and temperature-programmed reduction of H2. Catalytic properties were examined in terms of glycerol conversion, selectivity toward hydrogen and C-containing products in temperature range of 650-800 ℃.The effect of active metal reduction and residence time（thereby flow feed rate） was analysed. It was found that the growth of residence time increased the hydrogen selectivity in the whole temperatures range whereas the catalyst reduction, before the catalytic process, decreased the hydrogen selectivity at temperatures lower than 750 ℃. The cerium addition improved the catalytic behaviour for hydrogen production via glycerol steam reforming. Cerium oxide suppressed the sintering of cobalt particles and as a result Co-Ce/HAp ensured higher stability and H2 selectivity than Co/HAp. Under reaction conditions investigated in this study, the highest selectivity toward hydrogen at 650 ℃ was obtained for 7.5 Co-Ce/HAp catalyst.

关键词： Calcium hydroxyapatite cobalt catalysts cobalt-cerium catalysts Glycerol steam reforming

Ti-Si composite oxide-supported cobalt catalysts for CO_2 hydrogenation

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Journal of Natural Gas Chemistry 2011年第5期20卷 558-564页

作者： Jakrapan Janlamool Piyasan Praserthdam Bunjerd Jongsomjit Center of Excellence on Catalysis and Catalytic Reaction Engineering Department of Chemical Engineering Faculty of Engineering Chulalongkorn University

In the present work, different silica-based supported cobalt （Co） catalysts were synthesized and used for CO2 hydrogenation for methanation. Different supports, such as SSP, MCM-41, TiSSP and TiMCM were used to prepare Co catalysts with 20 wt% Co loading. The supports and catalysts were characterized by means of N2 physisorption, XRD, SEM/EDX, XPS, TPR and CO chemisorption. It is found that after calcination of catalysts, Ti is present in the form of anatase. The introduction of Ti plays important roles in the properties of Co catalysts by：（i） facilitating the reduction of Co oxides species which are strongly interacted with support, （ii） preventing the formation of silicate compounds, and （iii） inhibiting the RWGS reaction. Based on CO2 hydrogenation, the CoTiMCM catalyst exhibites the highest activity and stability.

关键词： CO2 hydrogenation titania-silica cobalt catalysts methanation

The role of CO_(2)dissociation in CO_(2)hydrogenation to ethanol on CoCu/silica catalysts

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Nano Research 2023年第5期16卷 6128-6133页

作者： Zhongyan Wang Chengsheng Yang Xianghong Li Xiwen Song Chunlei Pei Zhi-Jian Zhao Jinlong Gong Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and EngineeringTianjin UniversityTianjin 300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

CoCu-based catalysts are widely used in CO_(x) hydrogenation reactions to produce higher alcohols due to the C–C coupling ability of Co and the ability of Cu to produce alcohols.This work describes the role of easily happened CO_(2)dissociation on the CoCu surface during the reaction,using different silica support to tune the metal–support interaction,reaches different selectivity to ethanol.CoCu supported on mesoporous silica MCM-41 shows ethanol selectivity as high as 85.3%,the ethanol space-time yield(STY)is 0.229 mmol/(gmetal∙h),however,poor selectivity to ethanol as low as 28.8%is observed on CoCu supported on amorphous silica.The different selectivity is due to the different intensities of CO_(2)dissociation on the catalysts.The adsorbed O*produced via CO_(2)dissociation can occupy the cobalt hollow sites on CoCu surfaces,which are also the adsorption sites of C1 intermediates for further C–C coupling.

关键词： CO_(2)hydrogenation bimetallic catalysts cobalt catalysts CO_(2)dissociation ethanol synthesis

Effect of vacuum impregnation on the performance of Co/SiO_2 Fischer-Tropsch catalyst

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Journal of Natural Gas Chemistry 2011年第4期20卷 350-355页

作者： Xiaofeng Zhou Qingling Chen Yuewu Tao Huixin Weng Research Center of Petroleum Processing East China University of Science and Technology Shanghai 200237 China Shanghai Research Institute of Petrochemical Technology SINOPEC Shanghai 201208 China

Two silica-supported cobalt catalysts were prepared by incipient wetness impregnation under atmospheric and vacuum conditions.N2 ph- ysisorption,H2 chemisorption,XRD,SEM,TEM,XPS and H2-TPR were used to characterize the catalysts.The results showed that the impregnation methods had an effect on the size,dispersion and reducibility of cobalt particles.Under vacuum conditions,cobalt-containing steeping liquor could penetrate into the inner pores of silica support and more bivalent cobalt oxides were formed in the Co3O4 crystallites.Furthermore,cobalt precursors were rarely inclined to agglomerate and the smaller cobalt particles were uniform on the support,which led to the higher activity of the Co/SiO2（B）catalyst than the normal one under the reaction conditions of 483- 523 K,1 - 2 MPa,gas hourly space velocity of 500–1000 h-1 and molar ratio of H2/CO=0.5 - 2.0.

关键词： Fischer-Tropsch synthesis cobalt catalysts silica vacuum impregnation

CO oxidation over Co_3O_4/SiO_2 catalysts:Effects of porous structure of silica and catalyst calcination temperature

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Journal of Natural Gas Chemistry 2010年第6期19卷 583-588页

作者： Jian Zheng Wei Chu Hui Zhang Chengfa Jiang Xiaoyan Dai . Key Laboratory of Green Chemistry and Technology of Ministry of Education and Department of Chemistry Sichuan University Chengdu 610064 Sichuan China Department of Chemical Engineering Sichuan University Chengdu 610065 Sichuan China Sichuan Provincial Research Institute of Safety Science and Technology Chengdu 610012 Sichuan China

The catalytic performances of Co 3 O 4 /SiO 2 catalysts prepared by incipient wetness impregnation for CO oxidation were investigated using three kinds of silica as carriers with different pore sizes of 7.7, 14.0 and 27.0 nm. The effects of calcination temperature on the catalyst surface and micro structure properties as well as catalytic performance for the oxidation of carbon monoxide were also studied. All catalysts were characterized by N 2 adsorption-desorption, XRD, XPS, FTIR, H 2 -TPR and O 2 -TPD. It was found that the properties and crystal size of cobalt-containing species strongly depended on the pore size of silica carrier. While the silica pore size increased from 7.7 to 27.0 nm, the Co 3 O 4 crystal size increased from 8.5 to 13.5 nm. Moreover, it was demonstrated that if the spinel crystal structure of Co 3 O 4 was obtained at a calcination temperature as low as 150 °C, the catalyst sample would have a high Co 3 O 4 surface dispersion and an increase of surface active species, and thus exhibit a high activity for the oxidation of carbon monoxide.

关键词： cobalt catalysts carrier porosity catalytic property calcination temperature oxidation of carbon monoxide

Stable and efficient metal-biochar supported catalyst:degradation of model pollutants through sulfate radical-based advanced oxidation processes

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Biochar 2020年第3期2卷 319-328页

作者： Fermín Delgado Victoria S.Gutierrez Mariana Dennehy Mariana Alvarez INQUISUR Departamento de QuímicaUniversidad Nacional del SurAv.Alem 12538000 Bahía BlancaArgentina Planta Piloto de Ingeniería Química PLAPIQUI(CONICET-UNS)Camino La Carrindanga Km 78000 Bahía BlancaArgentina

This study focuses on the synthesis of metal-based biochar catalysts and their catalytic activation of peroxymonosulfate(PMS,HSO5−)for the degradation of three different wastewater model pollutants employing advanced oxidation processes(AOP).Iron,copper,and two different cobalt-based catalysts were prepared and evaluated.The catalysts were supported on a biochar obtained from the pyrolysis of woody pruning wastes.They were characterized by C,H,and N elemental analysis,X-Ray diffraction(XRD),Fourier-transform infrared spectroscopy(FTIR),and scanning electron microscope(SEM).The metal content in each catalyst was determined by means of atomic absorption spectroscopy(AAS).The degradation reac-tions of benzoic acid(BA),catechol(C),and cinnamic acid(CA)were carried out in a lab scale batch glass reactor and were followed by UV-Visible spectroscopy(UV-Vis).A colorimetric technique was employed to verify the presence of oxidant during the reaction progress.The catalyst/oxidant optimal ratio was determined for the cobalt catalysts.The mineralization degree of the pollutants after the degradations was verified by means of total organic carbon(TOC)content in the residual liquids.After 4 h of reaction,the maximum mineralization was reached when C was treated with a cobalt-based catalyst(>80%),and its stability was evaluated through successive cycles of use.

关键词： Biochar Organic pollutants Advanced oxidation processes Sulfate radicals cobalt catalysts

Low Environmental Load Process for the Beckmann Rearrangement of Cycloalkanone Oximes by Bronsted Acid Catalyst with cobalt Salts

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International Journal of Organic Chemistry 2015年第3期5卷 147-152页

作者： Hidetoshi Yamamoto Masahiro Komeda Ayana Ozaki Michinori Sumimoto Kenji Hori Tsunemi Sugimoto Graduate School of Science and Engineering Yamaguchi UniversityUbeJapan Ube Laboratory Ube IndustriesLtdUbeJapan

Beckmann rearrangements of oximes to lactams often require harsh conditions and/or the use of large amounts of acid catalyst. To reduce the amount of Bronsted acid required, and to avoid the formation of a large amount of undesirable byproducts under mild reaction conditions, a low environmental load process was developed. Beckmann rearrangements of cyclohexanone oxime and cyclooctanone oxime were achieved using a combination of a Bronsted acid and cobalt tetra-fluoroborate hexahydrate. Various Bronsted acid catalysts (10 - 20 mol%) were used to obtain the corresponding lactams in high yields at 80℃.

关键词： Beckmann Rearrangement Cycloalkanone Oximes Lactam cobalt catalysts Bronsted Acids

Co（Ⅱ）-Catalyzed Regioselective Pyridine C-H Coupling with Diazoacetates

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Co（Ⅱ）-Catalyzed Regioselective Pyridine C-H Coupling with...