The research of ionic liquids and their applications in catalysis are attracting increasing attention in chemistry and chemical engineering. A supported ionic liquid catalyst (SILCA) consists of immobilized catalytic species (e.g.,transition-metal particles, metal complexes, or enzymes) residing in an ionic liquid layer immobilized on a poroussolid support. The kinetics of cinnamaldehyde hydrogenation over SILCAs that contained palladium nanoparticlesin ionic liquid, which, in turn, was immobilized on active carbon cloth (ACC), was studied and modeled in detail. A mechanistic kinetic model, which describes the differences of the activity and selectivity of the catalysts consistingof different ionic liquids, was developed. The model explained the experimental results well.