This is a study of metal-support interactions and promoter effects on platinum supported on cation-exchanged zeolite L. The effects of alkali and alkaline earth cations exchanged into the zeolite, the type of support (zeolite L versus alumina), and platinum particle size on the catalytic activity and electronic properties of the platinum are studied. The catalysts are tested for heptane dehydrocyclization, toluene dehydrogenation, and neopentane hydrogenolysis. The electronic properties of platinum are characterized by infrared spectroscopy of adsorbed carbon monoxide and by X-ray photoelectron spectroscopy. Platinum deposited on barium-potassium zeolite L is an active and selective catalyst for the octane enhancement of unleaded gasoline. Related systems have demonstrated metal-support interaction that influence performance. This study investigates such effects in a series of catalysts used in production of gasoline and should lead to improved performance and/or better control in the catalytic processes.
