Unavailability factor in catalytic reactions. Isolation and steric hindrance

Hydrogenation of acetylene at transient conditions in the presence of olefins and carbon monoxide over palladium/alumina

“…The possibility that the hydrogenation of olefins can occur on metallic sites of different properties has been made use of in the mathematical modeling of, for example, the hydrogenation of propylene and isobutylene (Rogers et al (1966), Lih (1970), Mezaki (1968), Kolboe (1972)), where the active sites were assumed to differ in their capacity of mutually adsorbing the olefin and hydrogen. It is also worth mentioning that Hussey et al (1968), in mathematically modeling the hydrogenation of cycloalkenes, proposed two types of active sites that differ in their ability to adsorb the cycloalkenes reversibly.…”