The preparation of palladium carbene intermediates from diphenylketene is proposed. Experiments to trap these intermediates with alkenes have been conducted and optimized, with cyclopropanes being prepared in up to 69% yield. This methodology has shown to be compatible with olefins, ethers, esters, anhydrides and various benzannulated norbornyl derivatives. In addition, an unusual palladium(II) catalyzed cyclopropane isomerization has been observed. Various substrates have undergone this isomerization affording two different olefin products in up to 61% yield. A catalytic cycle for this process is proposed.

The preparation of palladium carbene intermediates from diphenylketene is proposed. Experiments to trap these intermediates with alkenes have been conducted and optimized, with cyclopropanes being prepared in up to 69% yield. This methodology has shown to be compatible with olefins, ethers, esters, anhydrides and various benzannulated norbornyl derivatives. In addition, an unusual palladium(II) catalyzed cyclopropane isomerization has been observed. Various substrates have undergone this isomerization affording two different olefin products in up to 61% yield. A catalytic cycle for this process is proposed.

In our study, 3D interconnection channels of mesoporous silica MCM-48 was used as template. We try to fill the channels with the metal precussor by ¡§incipient wetness¡¨ technique. After the reduction with H2, the composites containning metal Pd and MCM-48 could be obtained. Then, Pd nanowire network was obtained through HF etching. The mesoporous palladium nanoparticles are obtained and we try to use it as the catalyst in the Heck coupling reaction of £\-methylstyrene and p-bromoacetophenone. We find that our catalyst have different effect in this Heck reaction. The terminal and internal (E/Z form) isomer ratio variated in the reaction. In the future, we will attempt to apply our mesoporous Palladium nanoparticles as organic molecule storage. The MCM-48 and mesoporous Palladium nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution nitrogen adsorption.We used NMR and GC to trace the reaction. Heck reaction was performed as a test reaction to compare catalytic performances of the meosoporous Palladium nanoparticles and the catalyst of refrence.

Thèse de doctorat : Chimie moléculaire : Metz : 2007. / Thèse soutenue sur ensemble de travaux. Bibliogr.p. [10]. Annexes.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xi, 70, 76 p. : ill. Includes abstract. Includes bibliographical references (p. 67-70).

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: Oxidation; Palladium; Scanning Tunneling Microscopy; Palladium oxide; PdO morphology; PdO surface area measurement; Turnover rate for methane combustion; Oxygen. Includes bibliographical references.

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Hydrogen is considered to be the fuel of the future as it is clean and abundant. Together with the rapidly developing fuel cell technology, it can sustain an environmentally sound and efficient energy supply system. Developing the technologies of palladium-based membrane for hydrogen separation and palladium nanostructured materials for hydrogen sensing and hydrogenation catalysts makes the "hydrogen economy" possible. This is because these technologies will allow for commercially viable production of comparatively cheap and high-quality hydrogen, and safety of its application. Based on the market requirements and interest in the development of a hydrogen economy, the purposes of this thesis are to develop thin palladium membrane for hydrogen separation and to explore an economic method for the synthesis of palladium nanowires in potential engineering applications. The original contributions of this thesis are outlined below: / The investigation of deposition progress of a palladium membrane on porous stainless steel substrate illustrates that palladium deposits will form a network structure on pore areas of the substrate surface in the initial stages. A bridge model is presented to describe the formation of a membrane. This model is confirmed from the cross-section of the deposited membranes. Based on the bridge model and the experimental measurements of palladium membranes deposited on the pore area of the substrates, the thickness of a palladium membrane deposited on 0.2 mum grade porous stainless steel substrate can be effectively controlled around 1.5∼2 mum, and the thickness of a palladium membrane deposited on 2 mum grade porous Inconel substrate can be effectively controlled around 7.5∼8 mum. Comparing the thickness and quality of palladium membranes deposited on the same substrates with the data in the literature, the thicknesses of the membranes prepared in this program are lower. The obtained result will be beneficial in the design and manufacture of suitable membranes using the electroless deposition process. / In the initial deposition stages, palladium nanoparticles cannot be deposited at the surface of the SiO2 inclusions that appear at the substrate surface. With the extension of deposition time, however, palladium nanoparticles gradually cover the SiO2 inclusions layer by layer due to the advance deposited palladium nanoparticles on the steel substrate surrounding them. The effect of the SiO2 inclusions on palladium deposits cannot be neglected when an ultra-thin membrane having the thickness similar to the size of inclusions is to be built. / The chemical reaction between phosphorus (or phosphate) and palladium at high temperature can take place. This reaction causes surface damage of the membranes. If palladium membranes are built on the porous substrates that contain phosphorus or phosphate used in the inorganic binders, they cannot be used over 550°C. This result also implies that palladium membranes cannot be employed on the work environment of phosphorus or phosphates. / Palladium nanowires are well arranged by nanoparticles at the rough stainless steel surface. The formation procedures consist of 3 stages. In the initial stage, palladium nanoparticles are aligned in ore direction, then the nanowire is assembled continuously using follow-up palladium deposits, and finally the nanowire is built smoothly and homogeneously. It is also found that palladium nanoparticles generated from the autocatalytic reaction are not wetting with the steel substrate and they are not solid and easily deformed due to the interfacial tension when they connect to each other. / Various palladium nanowire arrays possessing the morphologies of single wires, parallel and curved wires, intersections and network structures are illustrated. The results demonstrate that palladium nanowires can be built in a self-assembled manner by palladium nanoparticles in the initial deposition stages. Such self-assembled nanowires may attract engineering applications because electroless deposition process and preparation of a substrate are simple and inexpensive. / The diameter of palladium nanowires can be effectively controlled by the concentration of PdCl2 in the plating solution and deposition time. The size of palladium nanoparticles generated from the autocatalytic reaction is directly dependent on the concentration of PdCl2 in the plating solution. The higher the concentration of PdCl2 in the plating solution is, the smaller the deposited palladium nanoparticles are. The experimental results provide a controllable method for the fabrication of palladium nanowire arrays with potential engineering applications.