Cobalt-containing catalytic systems alloyed with rare and rare-earth metals as catalysts for synthesis of hydrocarbons from CO and H<Subscript>2</Subscript>

To improve cobalt-containing catalytic systems for synthesis of hydrocarbons from carbon monoxide and hydrogen (Fischer-Tropsch synthesis), supports based on ultradispersed alloys of aluminum with rare and rare-earth metals (G, Ce, Sm) were obtained and studied. The catalytic activity parameters of the new catalysts were determined.     

Synthesis gas as substrate for the biological production of fuels and chemicals

Synthesis gas provides a simple substrate for the production of fuels and chemicals. Synthesis gas can be produced via established technologies from a variety of feedstocks including coal, wood, and agricultural and municipal wastes. The gasification is thermally efficient and results in complete conversion of the feedstock to fermentable substrate.Clostridium ljungdahlii grows on the synthesis gas components, carbon monoxide, hydrogen, and carbon dioxide. Production of acetic acid and ethanol accompanies growth with synthesis gas as sole source of energy and carbon. Rate and yield parameters are compared forC. ljungdahlii grown on carbon monoxide, or hydrogen with carbon dioxide.

     

一氧化碳加氢制碳氢化合物反应选择性的调控

合成气（即一氧化碳加氢）催化转化制碳氢化合物的费托合成反应是煤、甲烷和生物质等非油基碳资源间接转化制液体燃料或化学品的关键步骤．在传统的费托合成催化荆上,产物服从Anderson．Schulz．Flory分布,特定产物的选择性差．设计和制备高选择性费托合成催化剂,实现C-C偶联产物选择性的调控,是现代C,化学最具挑战性的课题．本文概述了近年来有关c￡偶联机理方面的理论研究进展,简要总结了影响费托合成产物选择性的几个关键因素,着重阐述了活性金属尺寸及所处微环境对产物选择性和催化：舌性的影响．本文还评述了既具有一氧化碳加氢制高碳烃又具有高碳烃加氢裂解能力的双功能费托合成催化剂体系,并提出通过控制加氢裂解等二次反应控制费托合成产物选择性的新策略．     

贵金属助剂对费-托合成用钴基催化剂的促进作用

贵金属助剂促进的费-托合成用钴基催化剂具有高活性和长链烃(C₅⁺)选择性优越等特点,被广泛应用于由合成气制清洁燃料的合成反应中。 本文重点讨论了贵金属助剂对活性钴物种的结构（还原度、分散度、双金属颗粒或合金的构成）, 钴基催化剂稳定性以及其对费-托合成的反应速率和产物选择性的影响规律。     

On-line gas chromatographic analysis of light Fischer-Tropsch synthesis products

Summary A simple gas chromatographic system has been developed for the rapid on-line analysis of light Fischer-Tropsch products. This involves a single chromatography fitted with two columns, a porous-layer open-tubular column coated with KCl deactivated alumina and a packed Porapak-Q column. The capillary column separates the 16 most common C₁−C₄ hydrocarbons and permits a reasonable analysis of the hydrocarbons in the C₅−C₇ range. The packed column is used for the separation of methane, carbon monoxide, carbon dioxide, water and methanol. Retention characteristics for the analysis on the capillary column are presented. The total analysis cycle is 30 minutes.     

Methods for the Synthesis of μ-Hydrocarbon Transition Metal Complexes without Metal–Metal Bonds

Transition metal complexes in which hydrocarbons serve as σ,σ-, σ,π- or π,π-bound bridging ligands are currently of great interest. This review presents efficient and directed syntheses for such compounds, which often have very aesthetic structures. These reactions are among the most important reaction types in modern organometallic chemistry. They can be a useful aid for the synthesis of tailor-made compounds, for example, for models of catalytic processes and, specifically, for the construction of heterometallic compounds. We will discuss reactions of electrophilic complexes with nucleophilic ones, numerous transformations of (functionalized) hydrocarbons with metal complexes, the currently very topical complexes with bridging acetylide and carbide ligands, and organometallic polymers, which can be expected to have interesting and novel materials properties. Chisholm

1 M. H. Chisholm, Polyhedron 1988 , 7, 757–1077.

has described the importance of these complexes as follows: “Central to the development of polynuclear and cluster chemistry are bridging ligands and central to organometallic chemistry are metal–carbon bonds. Thus bridging ligands hold a pivotal role ins the development of Binuclear and polynuclear organometallic chemistry”.     

Recent advances in understanding the key catalyst factors for Fischer-Tropsch synthesis

Catalytic conversion of synthesis gas (CO+H₂) into hydrocarbons, also known as Fischer-Tropsch (FT) synthesis, is a crucial reaction for the transformation of non-petroleum carbon resources such as coal, natural gas, shale gas, coal-bed gas and biogas, as well as biomass into liquid fuels and chemicals. Many factors can influence the catalytic behavior of a FT catalyst. This review highlights recent advances in understanding some key catalyst factors, including the chemical state of active phases, the promoters, the size and the microenvironment of active phase, which determine the CO conversion activity and the product selectivity, particularly the selectivity to C₅₊ hydrocarbons.     

Enantioselective C?C and C?H Bond Formation Mediated or Catalyzed by Chiral ebthi Complexes of Titanium and Zirconium

The development of catalytic processes that effect enantioselective bond formation under mild conditions is an important and challenging task in modern chemical synthesis. In this connection, chiral C₂-symmetric ansa-metallocenes (bridged metallocenes) have found notable applications as catalysts. This article discusses the chemistry of this class of chiral metallocene complexes with regard to their utility in catalytic and enantioselective C? C and C? H bond formation reactions. In addition, where applicable, a brief comparison with other related catalytic enantioselective processes is offered. Many of the reactions effected with high levels of enantioselectivity by catalytic amounts of these complexes are of great significance to the preparation of new materials and in the synthesis of therapeutic agents. For example, zirconocene complexes readily catalyze the enantioselective addition of alkylmagnesium halides to alkenes, and cationic zirconocene complexes may promote the highly stereoregulated copolymerization of terminal alkenes. Furthermore, the related chiral titanocenes are involved in an impressive range of useful asymmetric catalytic reactions, including the enantioselective hydrogenation of olefins and reduction of imines or ketones. This review attempts to bring together the practical aspects of the use of [(ebthi)M] complexes of Group 4 transition metals (catalyst synthesis and resolution), outline the manner in which the C₂-symmetric chiral ligands are believed to initiate stereoselective bond formation, and highlight the aspects of this chemistry that are less well understood and require further research.     

MOFs衍生炭负载的钴基催化剂的廉价制备及其CO加氢催化性能

以对苯二甲酸（H₂BDC）为配体、乙酸钴为Co源、水作溶剂,通过共沉淀法合成了金属有机框架材料（Co-BDC MOFs）;以其为前驱体分别在乙炔和氩气氛下采用化学气相沉积法制备了核壳结构Co@C催化剂。结合XRD、氮吸附、SEM、TEM、XPS、TGA和Raman光谱等手段对Co@C催化剂的结构和组成进行了表征,考察了该催化剂在费托合成反应中的活性及稳定性。结果表明,炭化气氛对炭层结构的石墨化程度有较大影响,而对金属Co核的物相结构和粒径影响较小;乙炔气氛有助于形成多孔的石墨炭壳,从而促进烃链的生长,Co@C-C₂H₂催化剂上的C₅₊烃产物选择性高达82.66%,反应过程中催化剂物相由单相金属Co转变为金属Co与Co₂C的混合相,且无失活现象发生,表明Co₂C具有较高的费托反应催化活性。     

Catalytic Activity of Thermolyzed [Co(NH3)6][Fe(CN)6] in CO Hydrogenation Reaction

Currently, the processes of obtaining synthetic liquid hydrocarbons and oxygenates are very relevant. Fischer-Tropsch synthesis (FTS) is the most important step in these processes. The products of thermal destruction in argon of the mixture [Co(NH₃)₆][Fe(CN)₆] and Al(OH)₃ were used as catalysts for CO hydrogenation. The resulting compositions were studied using powder X-ray diffraction, IR spectroscopy, elemental analysis, SEM micrographs. The specific surface area, pore and particle size distributions were determined. It was determined that the DCS-based catalysts were active in the high-temperature Fischer-Tropsch synthesis. The effect of aluminum in the catalyst composition on the distribution of reaction products was revealed.     

β-Cyclodextrin for design of alumina supported cobalt catalysts efficient in Fischer-Tropsch synthesis

Addition of β-cyclodextrin during catalyst preparation strongly affects the structure and catalytic performance of alumina supported cobalt catalysts for Fischer-Tropsch synthesis. Impregnation of the support with solutions containing β-cyclodextrin leads to higher metal dispersion and spectacularly enhances both reaction rate and heavy hydrocarbons productivity in Fischer-Tropsch synthesis.     

From Solar Energy to Fuels: Recent Advances in Light‐Driven C1 Chemistry

Catalytic C₁ chemistry based on the activation/conversion of synthesis gas (CO+H₂), methane, carbon dioxide, and methanol offers great potential for the sustainable development of hydrocarbon fuels to replace oil, coal, and natural gas. Traditional thermal catalytic processes used for C₁ transformations require high temperatures and pressures, thereby carrying a significant carbon footprint. In comparison, solar‐driven C₁ catalysis offers a greener and more sustainable pathway for manufacturing fuels and other commodity chemicals, although conversion efficiencies are currently too low to justify industry investment. In this Review, we highlight recent advances and milestones in light‐driven C₁ chemistry, including solar Fischer–Tropsch synthesis, the water‐gas‐shift reaction, CO₂ hydrogenation, as well as methane and methanol conversion reactions. Particular emphasis is placed on the rational design of catalysts, structure–reactivity relationships, as well as reaction mechanisms. Strategies for scaling up solar‐driven C₁ processes are also discussed.     

Mass- and heat-transfer-enhanced catalyst system for Fischer-Tropsch synthesis in fixed-bed reactors

Fischer-Tropsch synthesis (FTS) was carried out using Al₂O₃-supported Co catalyst coated on metallic monolith. Considering the liberation of a large amont of heat from the highly exothermic FTS reaction, catalytic activity of Co catalyst coated on metallic monolith was tested and compared with that of pellet-type catalysts. The reaction was carried out in a conventional tubular fixed-bed reactor and simulated distillation (SIMDIS) analysis method was used to determine the liquid products distribution. Proper control of degree of reaction, as well as the reaction temperature gave rise to a shift of products selectivity toward higher hydrocarbons, especially C₁₃?C₁₈ diesel range hydrocarbons.     

Catalytic transformations of gaseous products of plasma treatment of solid wastes and hydrocarbon raw materials

The layout of a technological process including catalytic steam and carbon dioxide reforming and Fischer-Tropsch hydrocarbon synthesis is presented. The inclusion of catalytic stages in plasma technologies provides the possibility to intensify conversion processes, enhance their depth, and obtain various gaseous and solid products.     

Development of Efficient Zeolite-Containing Catalysts for Petroleum Refining and Petrochemistry

The role of various technologies in oil refining and petrochemistry changes due to amendments to the requirements for fuel quality. The development of these technologies requires the improvement of catalysts. This paper outlines main procedures for the production of dealuminated zeolites, as well as the advantages and drawbacks of these procedures. Catalysts with a high desulfurizing ability for the hydrocracking of vacuum gas-oil to gasoline and diesel fractions and catalysts for the isomerization of fuel hydrocarbons can be prepared using ultrastable Y-type zeolites. The results of testing of zeolite-containing binary catalytic systems in Fischer-Tropsch synthesis are presented.     

Contemporary Problems in the Selective Catalytic Reduction of Nitrogen Oxides (NOx)

The results from investigation of the processes involved in the catalytic reduction of nitrogen oxides are reviewed: 1) with carbon monoxide and other combustible gases (H₂, C _n H _m ) at a developed block honeycomb palladium-containing catalysts; 2) with ammonia (the SCR process) at vanadium-containing and complex oxide (Cu-Cr, Fe-Cr/-Al₂O₃) catalysts; 3) with light C₁-C₄ hydrocarbons at cation-exchange zeolites (pentasils, natural and synthetic mordenites). Mechanisms and kinetic models are proposed, and the regions of a positive and negative effect from oxygen and sulfur dioxide on the processes involved in the reduction of nitrogen oxides are established.     

The development of a catalytic synthesis of münchnones: a simple four-component coupling approach to alpha-amino acid derivatives

A new palladium-catalyzed route to prepare 1,3-oxazolium-5-oxides (i.e., Münchnones) directly from imine, carbon monoxide, and acid chloride building blocks has been developed. This provides a straightforward catalytic synthesis of Münchnones and is amenable to generating a diverse range of products by simple modification of the imine or acid chloride starting materials. Münchnones are vital synthetic intermediates to a variety of heterocyclic and peptide-based molecules. As such, this methodology has been utilized to design a new catalytic synthesis of alpha-amino acid derivatives via a one-pot coupling of imines, carbon monoxide, and acid chloride followed by alcohol. The latter represents the first reported catalytic synthesis of alpha-amino acids directly from imine and carbon monoxide building blocks.     

Catalytic deoxygenation of organic compounds by carbon monoxide: III. The reaction under pressure of aromatic nitro compounds in the presence of o-phthalaldehyde

The reaction of o-phthalaldehyde with several aromatic nitro compounds in the presence of carbon monoxide and catalytic quantities of hexarhodium-hexadecacarbonyl eventuated in the formation of the corresponding N-substituted isoindolinone as the major product. A reaction mechanism has been suggested incorporating deoxygenation of the nitro compound by carbon monoxide to a nitrene intermediate and the subsequent interception of the latter by o-phthalaldehyde.     

Photoreduction of an α-Dichloroketone

We describe here a simple three step synthesis of B-santalene (1), one of the main hydrocarbons in East Indian Sandalwood oil,³ using the readily available camphene sultone (2) as a starting material. This synthesis, outlined in Figure 1, features the novel use of a sultone as a carbon activating group and involves a new desulfurization procechrre.     

A Novel Synthesis of Berbines1-Synthesis of 2,3-Dimethoxy-10,11-Methylenedioxyberbine by Use of Palladium Catalyzed Insertion of Carbon Monoxide

Palladium catalyzed amidation has recently been reported for the synthesis of benzolactams². We wish to report a simple and efficient method for the synthesis of berbines by the Palladium catalyzed insertion of carbon monoxide under mild reaction conditions such as an atmospheric pressure of carbon monoxide at 95° by use of a catalytic amount of Pd(OAc)₂ and PPh₃ in presence of a tertiary amine. The approach has wider applicability in the berbine synthesis³ as examplified by the synthesis of 2,3-dimethoxy-10,11-methylene-dioxyberbine 7. The bromo-1-benzyl tetrahydroisoquinoline derivative 5 ⁴, the key precursor, was prepared from the known reaction sequence involving an Schotten-Baumann condensation⁵ and B.N. reaction followed by sodium borohydride reduction.