The selective hydrogenation of crotonaldehyde has been investigated over a monometallic Pt/SiO2 catalyst and platinum bimetallic catalysts where the second metal was either silver, copper, or tin. The effects of addition of a second metal to the Pt/SiO2 system on the selectivity to crotyl alcohol were investigated. The Pt-Sn bimetallic catalysts were characterized by hydrogen chemisorption, 1H NMR and microcalorimetry. The Pt-Ag/SiO2 and Pt-Cu/SiO2 catalysts were characterized by hydrogen chemisorption. Pt-Sn/SiO2 catalysts selectively hydrogenated crotonaldehyde to crotyl alcohol and the method of preparation of these catalysts affected the selectivity. The most selective Pt-Sn/SiO2 catalysts for the hydrogenation of crotonaldehyde to crotyl alcohol were those in which the Sn precursor was dissolved in a HCl solution. Sn increased both the rate of formation of butyraldehyde and the rate of formation of crotyl alcohol. The Pt/SiO2, Pt-Ag/SiO2 and Pt-Cu/SiO2 catalysts produced only butyraldehyde. Initial heats of adsorption ((approximately)90 kJ/mol) measured using microcalorimetry were not affected by the presence of Sn on Pt. We can conclude that there is no through metal electronic interaction between Pt and Sn at least with respect to hydrogen surface bonds since the Pt and Pt-Sn at least with respect to hydrogen surface bonds since the Pt and Pt-Sn had similar initial heats of adsorption coupled with the invariance of the 1H NMR Knight shift.

In this thesis we studied the kinetics of crotonaldehyde hydrogenation on a series of Pt-cerium oxide and Pt-titanium dioxide catalysts to elucidate some mechanistic aspects of partial hydrogenation processes, which occurs on bi-functional catalyst systems. Studies in the literature have shown that the C=O bond hydrogenation of unsaturated aldehydes, more specifically of the crotonaldehyde species, only occurs when a platinum/metal-oxide interface exist, and does not occur on pure platinum or metal oxide surfaces. The mechanism of this process and the determination of the active site of crotonaldehyde have never been investigated. Because the presence of Pt/metal-oxide interfaces lead to this selective C=O bond hydrogenation, the active site is hypothesized to occur on the platinum/metal-oxide interface. However, possibilities of the active site being at the platinum sites or scaling with the metal-oxide sites remains. In this study we show that the active site occurs on the platinum within some distance from the interface of the two phases. We also show in this study that within a region of cerium oxide nanocubes which are uniformly packed on a platinum surface there exist no C=O bond activity, however at the interface between rafts of cerium oxide nanoparticles there exhibits significant enhancements to the C=O bond product. These results provide strong evidence that the chemistry for this C=O bond pathway extends beyond the three phase boundary of the platinum/metal-oxide alone. The results from this study provide insight into fundamental design parameters for designing highly selective bi-functional nanocatalysts.

This book provides state-of-the-art reviews, the latest research, prospects and challenges of the production of platform chemicals such as C6 sugars, 5-hydroxymethylfurfural, furfural, gamma-valerolactone, xylitol, 2,5-furandicarboxylic acid, levulinic acid, ethanol and others from sustainable biomass resources using processes that include heterogeneous catalysis, ionic liquids, hydrothermal/solvothermal, electrochemical and fermentation methods. It also discusses the application of these chemicals and their derivatives for synthesizing commodity chemicals via various routes. Intended as a reference resource for researchers, academicians and industrialists in the area of energy, chemical engineering and biomass conversion, it provides a wealth of information essential for assessing the production and application of various biomass-derived platform chemicals using biological, chemical and electrochemical techniques.

The proceedings of the VIIth International Symposium on the Scientific Bases for the Preparation of Heterogeneous Catalysts, are in line with the general scope of this series of events. Emphasis in all Symposia has been on the scientific aspects of the preparation of new and industrial catalysts, or on new methods of preparation, rather than on the catalytic reactions in which such solids are ultimately used. In the present context, the catalytic event itself has only been considered as another, though often decisive, method of catalyst characterization.