Metal Catalysts Supported on Zeolite. I. A Study on Platinum Particles Distribution

Zeolite 13Y, loaded with platinum cations by ion exchange, was calcined in the air and subsequently reduced in a hydrogen stream. Hydrogen and carbon monoxide adsorption studies, together with an electron microscopic observation of the catalyst, revealed that the size distribution of platinum particles is controlled by the calcination temperature. The hydrogen chemisorption method gave the average particle diameters, which were in fairly good agreement with the observations made by means of an electron microscope on the catalyst with a platinum particle diameter larger than 20 A, while trace amounts of hydrogen chemisorption were observed for platinum particles less than 20 A.