Download or read book Synthesis and Characterization of pyrazolylphosphinite Nickel II and Palladium II Complexes and Their Catalytic Activity Towards Olefin Oligomerization written by Juliana Mana Edor and published by . This book was released on 2016 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Nickel Palladium and Chromium Complexes as Olefin Oligomerization Catalysts written by Moses Mokgolela Mogorosi and published by . This book was released on 2009 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pyrazole and Pyrazolylethylamine Nickel II and Palladium II Complexes as Catalysts for Olefin Oligomerization and Friedel Crafts Alkylation Reactions written by Lerato Petunia Moeti and published by . This book was released on 2014 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ferrocenylpyrazolyl Nickel II and Palladium II Complexes as Pre catalysts for Ethylene and Higher alpha olefins Reactions written by Collins Obuah and published by . This book was released on 2014 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Catalytic Activity of Palladium II Imine Complexes in Heck Reaction written by Siti Rosilah Arsad and published by . This book was released on 2010 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Catalytic Testing of Palladium and Nickel Based Intermetallic Compounds for Acetylene Semi hydrogenation written by Anish Dasgupta and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermetallic compounds often offer opportunities for synthesis of site isolated catalysts having precise active site coordination and morphology. They are also resistant to segregation effects (compared to random alloys) because of the high heat of formation of their unique electronically stabilized crystal structures. Due to predictable, periodic and easily reproducible nature of the isolated active sites, suitably chosen intermetallic compounds can act as excellent model systems for studying catalytic structure function correlation in different small molecule chemistries. In the current dissertation I utilized H2-D2 exchange in addition to ethylene and acetylene hydrogenation as the probe reactions of choice. My ultimate target is to understand and quantify the effect of active site (transition metal) isolation during the semi-hydrogenation of acetylene in an ethylene rich stream, which is a key step in industrial polyethylene synthesisa multi-hundred-billion-dollar industry. I studied two different classes of catalysts for this chemistry: Pd-(M)-Zn (M=Cu, Ag, Au) -brass intermetallics and Ni-Ga intermetallics. I used micron scale bulk materials as model catalysts because they provide greater compositional control and allows for studying the intrinsic catalytic property of the intermetallic, free from support and ligand effects.A significant part of the text is dedicated to the synthesis, characterization and catalytic study of the bulk Pd-(M)-Zn ternary -brass phase materials because of its unique adaptability in terms of developing a family of closely related model catalysts having Pd-M-Pd active sites (M=Pd, Zn, Au, Cu and Ag) which can change the semi-hydrogenation activity and selectivity by two orders of magnitude even when only one atom is changed per 52 atom unit cell. As an extension of this project I also report several Pd-Ni-Zn and Pd-Pt-Zn ternary -brass phases and determine their atomic site occupancy factors.During the course of my research I realized there were no reported methods for synthesizing Pd-Zn and Ni-Zn -brass intermetallics as catalytically relevant supported nano-particles (NPs). I developed and optimized a hybrid generalized synthesis approach for SiO2 supported Pd-Zn, Ni-Zn and Cu-Zn -brass NPs. I also provide preliminary evidence that this approach can be easily extended to the synthesis of ternary NPs as well.In the case of Ni-Ga intermetallics, I tried to understand the role of Ga in controlling acetylene semi-hydrogenation. I observed a reversal in the ethylene selectivity trend with Ga content between 85 C and 160 C which is unexpected based on published DFT calculations. Previously, it has been suggested that Ga simply acts as a spacer for isolating Ni/Pd active sites much like Zn in the case of Ni-Zn catalysts (studied by Charles Spanjers from our research group). However, Ga has a higher affinity to hydrogen compared to Zn and I attempted to investigate if Ga may have a weak but non-negligible catalytic contribution towards hydrogenation which has typically not been previously considered in any detail in the case of acetylene semi-hydrogenation on metallic catalysts. Additionally, I provide understanding behind the high acetylene semi-hydrogenation selectivity of Ni5Zn21 catalyst which was originally reported by Spanjers et al. (J. Catal. 2014). This involved identifying the site occupation factor of Ni and Zn in the -brass lattice for materials having greater than 15.4 at% Ni. It is determined that (unlike Pd-Zn -brass) exactly single atom Ni1 active sites are exposed on the surface irrespective of the Ni concentration (even though Ni3 clusters are present in the bulk) which explains the suppression of over-hydrogenation and oligomerization on this catalyst, resulting in the high ethylene selectivity reported by Spanjers et al.
Download or read book Bis pyrazolyl Chromium III Nickel II and Palladium II Complexes as Ethylene Oligomerization and Polymerization Catalysts written by Nangamso Alicia Miti and published by . This book was released on 2008 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Catalytic Activity of Palladium II Aroylhydrazone Complexes in Mizoroki heck Reaction written by Nur Hafizah Hassan and published by . This book was released on 2015 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Evaluation of Ferrocenylpyrazolyl and Ferrocenylpyrazolyl phosphine Palladium and Nickel Complexes as Ethylene Oligomerization Catalysts written by Arnoux Van der Westhuizen and published by . This book was released on 2011 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pyrazolyl Nickel and Palladium Complexes as Catalysts for Ethylene Oligomerization and Olefins and Carbon Monoxide Co polymerization Reactions written by Collins Obuah and published by . This book was released on 2011 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Sterically Optimized Cationic Diphospalladium II Complexes and Their Application in the Alternating Copolymerization of Olefins with Carbon Monoxide written by Markus Schmid and published by . This book was released on 1999 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pyrazolyl Palladium II Complexes as Phenylacetylene Oligomerization and Polymerization Catalysts written by Tebogo Vincent Segapelo and published by . This book was released on 2004 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyrazolyl compounds have been extensively used to prepare metal complexes, but it is only recently that they have been investigated as catalysts for the polymerization of unsaturated hydrocarbons. In catalyzing the polymerization of ethylene, the electrophilicity of the metal centre plays an important role since the key step in the polymerization is coordination of the ethylene. A similar facile coordination would be expected for acetylene and one would therefore expect pyrazolyl palladium complexes to be good catalysts for the transformation of acetylenes. This thesis was an investigation of pyrazolyl palladium complexes as catalysts for the polymerization and oligomerization of substituted acetylenes.
Download or read book Synthesis Characterization and Catalytic Activity of Polystyrene Anchored Palladium II hydrazone Complexes in Heck Reaction written by Nur Rahimah Said and published by . This book was released on 2011 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer stabilized Transition Metal Nanocatalysts written by Olivier Jérémie Nguon and published by . This book was released on 2014 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel polymeric architectures and analytical methods were designed for the synthesis, characterization, and applications of metallic nanocatalysts. Four main research areas were investigated, namely: i) palladium nanocatalysts, ii) metal content analysis by a novel microplasma-based technique, iii) polyion complex micelle-metal hybrid structures, and iv) nickel nanocatalysts. The solution and solid-state properties of dendrigraft (arborescent) polystyrene-graft-poly(2-vinylpyridine) copolymers were studied by dynamic light scattering (DLS) and atomic force microscopy (AFM). The unimolecular micelles exhibited good colloidal stability and narrow size distributions in organic solvents, and a fried egg morphology when deposited onto mica substrates. The preparation of stable colloidal Pd nanoparticles within the dendritic templates was reported for the first time. The diameter of the nanoparticles varied from 0.7 to 3.4 nm depending on the loading level, reduction time, and arborescent copolymer generation used. The catalytic activity of the colloidal Pd nanoparticles was evaluated in the Suzuki-Miyaura (SM) cross-coupling reaction under green conditions. Good catalytic activity and a positive dendritic effect were evidenced, although air-sensitivity and flocculation limited the activity and recyclability of the catalysts. To determine the concentration of Pd in the copolymers, a novel microplasma-based technique was applied in organic solvents for the first time. Metal quantification by microplasma-optical emission spectrometry revealed stoichiometric complexation of the Pd salt by the pyridine groups, and kinetic aggregation studies highlighted the benefits of the polymer for colloidal stability. To obtain Pd nanoparticles dispersible in high water content solutions, polyion complex micelles were synthesized from arborescent copolymers and double-hydrophilic block copolymers. The latter, viz. poly(acrylic acid)-block-poly(2-hydroxyethyl acrylate), were obtained by hydrolysis of poly(tert-butyl acrylate)-block-poly(2-trimethylsilyloxyethyl acrylate), synthesized by atom transfer radical polymerization. The self-assembled complexes formed supramolecular aggregates with hydrodynamic diameters of 132 to 354 nm and narrow size distributions. The assemblies exhibited thermo-responsive properties in ethanol, dissociating above ca. 35 °C and reforming upon cooling. The polyion complexes, with hydrodynamic diameters ranging from 110 to 306 nm, were stable in water and were used for the solubilization of Pd nanocatalysts for aqueous Suzuki-Miyaura reactions. Lastly, the properties of nickel nanoparticles prepared at Vale-Inco by a novel thermal decomposition method were investigated. The specific surface area of the bare nanopowders ranged from 6.4 to 97.2 m2g-1, and their catalytic activity in the hydrogenation of adiponitrile and mesityl oxide was higher than for commercial catalysts in some cases. Treatment of the nanoparticles with diethylenetriamine further improved their catalytic activity. Polymeric stabilizers were designed to maximize the dispersibility and catalytic activity of the nanopowders. The structures investigated included triblock copolymers of polystyrene with poly(ethylene oxide) or poly(2-vinylpyridine), and telechelic poly(ethylene glycol). Application of the polymer-stabilized nickel catalysts in hydrogenation yielded up to 15-fold increases in specific catalytic activity as compared to the bare particles. The polymer was also effective at preventing oxidation by air under storage.
Download or read book Palladium Reagents and Catalysts written by Jiro Tsuji and published by . This book was released on 1995 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Basic chemistry of organopalladium compounds; Classification of the reactions involving Pd(II) compounds and Pd(O) complexes.
Download or read book High valent Organometallic Palladium and Nickel Complexes and Their Roles in Carbon carbon and Carbon heteroatom Bond Formation Reactions written by Jason W. Schultz and published by . This book was released on 2016 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
