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Showing 1 to 20 of 41 for “"Homogeneous Catalysts"”.
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Graphite-conjugated catalysts : bridging heterogeneous and homogeneous catalysts
… by either metallic heterogeneous or molecular homogeneous electrocatalysts. Metallic heterogeneous catalysts have a continuum of electronic states that distribute the redox burden of multielectron reactions, allowing for efficient catalysis. However, heterogeneous catalysts display a variety of …
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High Pressure Nuclear Magnetic Resonance Studies of Homogeneous Catalysts
… a nuclear magnetic resonance probe for studying homogeneous catalysts from $-40\sp\circ$C to $100\sp\circ$C and pressures up to 4000 psi is described. Its significant features are a built-in stirring mechanism to mix the sample under study with reactive gases, and resolution and sensitivity …
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Continuous separation and recycle of homogeneous catalysts in small scale flow system
The development of organometallic catalysts with high activity and selectivity has transformed the way both bulk and fine chemicals are produced. When such catalysts are applied in fine chemicals production, the presence of toxic heavy metals in these catalysts (Pd, Pt, Ru, Rh, etc.) can pose …
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Liquid phase hydroformylation by zeolite supported rhodium
… of zeolites containing rhodium with that of homogeneous rhodium species as catalysts for liquid phase hydroformylation of 1-hexene in order to study the effects of zeolite immobilization. NaX zeolite was cation exchanged with several rhodium salts and used as hydroformylation catalysts at …
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The synthesis and chemistry of new carbosilane dendrimers and their use in polymerisation catalysis
The immobilisation of homogeneous catalysts is an area of research that attracts a great dela of attention. The immobilisation of catalysts on organic polymers and on inorganic materisl such as silica is a well known strategy. Recently, dendrimers have also been used as support materials. In this …
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Encapsulation of cobalt complexes in zeolite Y for use as hydroformylation catalysts
… the hydroformylation reaction is predominantly homogeneously catalysed using carbonyl complexes of cobalt and rhodium (1-3,45). The main disadvantage of homogeneous catalysts is that, especially for the longer chain hydrocarbon systems, very energy-intensive methods (such as distillation) are …
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Heterogeneous and Monolithic Catalyst Development for the Biodiesel Production Process & Evaluation of Static Mixers for the Esterification Process
… and sulphuric acid are the conventional homogeneous catalysts used, in spite of their drawbacks, such as soap formation with high free fatty acid (FFA) feedstocks, substantial wastewater generation, issues with the downstream separation process, and corrosion of process equipment. Both of …
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The development of novel hetrogeneous catalysts for the hydrogenation of prochiral imines
Catalysts have been studied for the enantioselective hydrogenation of prochiral imines. Work has centred on the support of homogeneous catalysts, with the intention of establishing a heterogeneous catalyst without loss of activity. Initially, established heterogeneous systems were investigated. As …
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Supporting Well-Defined Platinum Group Metals in Metal-Organic Frameworks for Heterogeneous Catalysis
… which require highly selective transformations, homogeneous catalysts are paramount. The effectiveness of molecular organometallic catalysts in particular can be largely attributed to the precise tools available for synthesis and characterization of the ligands and metal complexes, which allow …
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Robust Nickel Catalysts Supported By Biaryl-Bridged Pyridyl-N-Heterocyclic Carbenes For Carbon Dioxide Reduction To Value-Added Products
… for CO2 reduction involves the design of new homogeneous catalysts with tunable geometries and polyaromatic frameworks with increased delocalization to lower overpotentials for catalysis. We report a family of biaryl-bridged pyridyl-N-heterocyclic carbene-based ligands and their corresponding …
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Hydroformylation of olefins by water soluble and asymmetric cobalt and platinum complexes
… been placed on the development of immobilized homogeneous catalysts that combine the virtues of conventional heterogeneous and homogeneous catalysts. The objective of this dissertation is to investigate novel phosphine modified water soluble cobalt and platinum complexes as homogeneous and …
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Immobilized Bis-Indenyl Ligands for Stable and Cost-Effective Metallocene Catalysts of Hydrogenation and Polymerization Reactions
… fine chemicals, pharmaceuticals, and plastics. Homogeneous catalysts for the processes that have low stability and their separation is difficult. Therefore, the development of new highly active and stable catalysts for hydrogenations and polymerizations is a necessity. The objective of this …
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Zeolite encapsulated metal complexes as heterogeneous catalysts for oxidation reactions
… of zoilite-Y generates new heterogeneous catalysts. These catalysts were synthesized employing the flexible ligand method encapsulation technique.The structures of these encapsulated complexes were established on the basis of various physico-chemical and spectroscopic studies. The results …
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Investigations into cyclopropanation and ethylene polymerization via salicylaldiminato copper (II) complexes
… The first chapter addresses diastereoselective homogeneous copper catalyzed cyclopropanation reactions. Cyclopropanation of styrene and ethyl diazoacetate (EDA) is a standard test reaction for homogeneous catalysts. Sterically bulky salicylaldimine (SAL) ligands should select for the ethyl …
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Revealing Structural and Spin-state Dependent Reactivity of Single Atom Catalysts (SACs) with Systematically Improvable Computational Tools
Efficient catalysts are essential for advancing energy conversion and storage technologies, particularly for challenging reactions such as methane-to-methanol conversion and the oxygen reduction reaction (ORR) important for fuel cells. Single-atom catalysts (SACs), particularly doped graphitic …
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Ligand-bridged dinuclear carbonyl compounds of rutheniun and osmium
… CO)4(p -( 02CMe h(MeCN)2] (118), were tested as homogeneous catalysts for the isomerisation of terminal alkenes. Complex 4 was inactive while the complex 118 gave a 100 % conversion. It is proposed that the catalysis proceeded via the displacement of one acetonitrile ligand from the metal centre …
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Synthesis characterization, and reactivity of ruthenium maltolato complexes
… as well as to explore their viability as homogeneous catalysts, particularly inaqueous media. The compounds Ru(ma)2(PPh3)2 (1), Ru(ma)2(DMS0)2 (2), Ru(ma)2(COD) (3) and RuH(ma)(C0)(PPh3)2 (4) (where Hma is maltol) were prepared by the interaction of potassium maltolate with RuC12(PPh3)4, …
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Development of O,N-bidentate ruthenium catalysts for isomerization and kinetic studies of ruthenium carbenes for C=C coupling reactions
… organometallic compounds have paved the way of homogeneous catalysis in producing bulk, fine chemicals, and even natural products. During the last decade, ruthenium catalysts have provided new indispensable synthetic methods that cannot be promoted by other catalysts and applied in wide range of …
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