Selective Hydrogenation of Polyunsaturated Hydrocarbons using SCILL-Type Catalysts

More about the book

In recent decades, ionic liquids have emerged as a powerful tool for catalyst design, particularly through the innovative Solid Catalyst with Ionic Liquid Layer (SCILL) concept. This approach was applied to two industrially relevant reactions: the partial hydrogenation of aromatics and the selective hydrogenation of acetylene in ethylene-rich feeds. The partial hydrogenation of aromatics is crucial for producing valuable intermediates for nylon synthesis. Traditionally reliant on liquid-phase processes, this work attempted to transfer the reaction to the gas phase, conducting a particle size study using ruthenium nanoparticles as small as 1.1 nm. This study revealed an unreported increase in selectivity for smaller particle sizes. The application of an ionic liquid film, particularly imidazolium-based, successfully enhanced solubility and adsorption on the catalyst surface, with organic modifiers like methanol significantly improving selectivity. In the case of acetylene hydrogenation, essential for producing polymer-grade ethylene, the challenge lies in preventing ethylene hydrogenation, which can lead to product loss and thermal runaway. The performance of an industrial Pd Ag alloy catalyst was notably enhanced by ionic liquid coating, which expanded the stable operating temperature range and suppressed the formation of deactivating oligomers. Investigating the catalysts under extreme conditions allowed for the definition o