S. M. Csicsery
Apr 1, 1988
Citations
0
Influential Citations
9
Citations
Journal
Journal of Catalysis
Abstract
Abstract The reactions of 1-methyl-2-ethylbenzene are useful for the characterization and evaluation of bifunctional catalysts (which have both acid and metal-type catalytic activities). Platinum (and iridium) catalyze dehydrogenation, dehydrocyclization to indan and indene, ring opening of indan to n -propylbenzene, and hydrogenolyses of the various side-chain bonds. Dehydrocyclization and hydrogenolysis of the aliphatic bond of the ethyl side chain increase with increasing platinum surface area. Certain other metals, such as nickel, catalyze only dehydrogenation and hydrogenolyses. Platinum on strongly acidic silica-alumina support has lower dehydrocyclization and isomerization activity than expected from the Pt surface area and from the acid activity of its support. Strong acid sites and platinum may interact with each other. The interaction reduces specific activities of each. With strongly acidic supports, dehydrocyclization may be a better measure of the available Pt than CO chemisorption, which is not always affected by such interactions. Isomerization and transalkylation of methylethylbenzene are acid-catalyzed reactions. These two reactions are about 100–300 times faster over platinum on a strongly acidic silica-alumina support than over platinum on silica. An advantage of the test is that it can simultaneously measure acid, dehydrocyclization, and hydrogenolysis activities.