Premium
Catalytic hydrogenation of propylene and isobutylene over platinum. Effect of noncompetitive adsorption
Author(s) -
Rogers G. B.,
Lih M. M.,
Hougen O. A.
Publication year - 1966
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690120230
Subject(s) - adsorption , isobutylene , chemistry , catalysis , olefin fiber , steric effects , molecule , reaction rate , reaction mechanism , inorganic chemistry , organic chemistry , computational chemistry , photochemistry , copolymer , polymer
A mathematical and kinetics model is presented for reactions catalyzed by solid surfaces where both competitive and noncompetitive adsorption take place, a situation that may be general in reactions between large and small molecules catalyzed by solid surfaces. In the adsorption of large molecules steric hindrance or multiple site adsorption cause maximum surface coverage of such molecules before all sites are occupied. This does not, however, preclude further adsorption of small molecules on the remaining isolated vacant sites nor does it preclude further surface reaction. The overall reaction model for such conditions may be expressed asThis particular model has been evaluated for the catalytic hydrogenation of propylene and isobutylene with the expectation that it may be useful in reactions that are of industrial importance. A reaction model based on either competitive adsorption or noncompetitive adsorption alone fails to correlate the experimental data. In these two reactions maximum rates occur at olefin concentrations below 5 mole % and the catalytic adsorption constants for the olefins are a hundredfold greater than for hydrogen. This reaction model is similar to that proposed by Bond and Turkevich ( 15 ), who have further demonstrated through the deuteration of propylene that the actual mechanism of the reaction is much more complicated.