Nitrile hydrogenation is the most commonly used method for preparing diverse amines. This thesis is aimed at the mechanism and factors affecting the performance of Ni-based catalysts in nitrile hydrogenations. Surface science techniques are used to study bonding of nitriles and amines to a Ni(111) surface and to identify surface intermediates. Liquid-phase hydrogenations of cyclohexene and 1-hexene on a Pt foil were carried out successfully. Finally, knowledge about the surface structure, surface chemical bond, dynamics of surface atoms (diffusion, growth), and reactivity of metal surfaces from solid-gas interface studies, is discussed.
The collection of contributions in this volume presents the most up-to-date findings in catalytic hydrogenation. The individual chapters have been written by 36 top specialists each of whom has achieved a remarkable depth of coverage when dealing with his particular topic. In addition to detailed treatment of the most recent problems connected with catalytic hydrogenations, the book also contains a number of previously unpublished results obtained either by the authors themselves or within the organizations to which they are affiliated.Because of its topical and original character, the book provides a wealth of information which will be invaluable not only to researchers and technicians dealing with hydrogenation, but also to all those concerned with homogeneous and heterogeneous catalysis, organic technology, petrochemistry and chemical engineering.
The electrolysis of water to produce hydrogen gas may form an important part of the world’s future economy as a way to store the energy for sustainable sources for later use. Part of what will determine if this use is practical is the efficiency of the catalysts used for the two half reactions that make up the electrolysis reaction. Presently in industry the cathodic reaction, the hydrogen evolution reaction (HER), is catalysed by nickel most commonly. Thus, there is a motivation to increase the activity of nickel toward the HER. Traditionally this was done by creating a high specific surface area or by increasing the intrinsic activity of nickel through alloying with other metals. Recently the importance using bifunctional catalysts for the HER was seen, this opened up a new line of investigation for methods to increase the activity of nickel HER catalysts. In this work a novel procedure to modify a nickel surface into highly active bifunctional catalyst is presented. The method is an electrochemical treatment that works by applying an alternating voltage to the nickel surface in a mildly acidic environment that causes it to oxidize in a manner similar to platinum. The platinum-like oxidation of the surface yields the Ni(OH)x structure (with x=0-2 across the surface), and allows a way to side step the problem of clumping of phases which is seen in bifunctional catalysts. The surface created by the treatment not only catalyses the HER, but also the urea electrooxidation, among other reactions. In this thesis the treated nickel surface is characterized and shown to be a highly active stable bifunctional catalyst, when the optimal parameters for the treatment are used. The characterization also shows that treated surfaces conform to the expectations of the novel Ni(OH)x structure. The treated surface is also seen to be active toward urea electrooxidation, but for slightly different parameters than the optimal parameters for a HER catalyst. Several practical elements of implementing the treatment in an industrial setting are dealt with. Finally, after concluding remarks, several new lines of enquiry that have been opened by this novel technique are briefly discussed.
After three meetings in Poitiers, France, the 4th International Symposium on Heterogeneous Catalysis and Fine Chemicals was held under the auspices of the New Swiss Chemical Society in Basel, Switzerland. Fundamental as well as applied contributions on the use of heterogeneous catalysis for the preparation of fine chemicals were presented and discussed. The program consisted of 4 plenary lectures, 28 oral contributions and around 90 posters covering a broad range of reactions and catalytic aspects. 82 of these contributions are collected in the present proceedings, grouped into the following 8 topical areas: - Industrial and engineering problems (7 contributions) - Alkylation and acylation reactions (11 contributions) - Enantio- and diastereoselective hydrogenation reactions (9 contributions) - Chemoselective hydrogenation reactions (12 contributions) - Oxidation reactions (14 contributions) - Immobilized and encapsulated complex catalysts (12 contributions) - Zeolite and clay catalysts (12 contributions) - Miscellaneous topics (5 contributions)
