Ea. Piocos et al., CATALYTIC TRANSFORMATIONS OF OLEFINS ON HZSM5 OBSERVED BY RADIOLYSIS EPR, Journal of physical chemistry, 100(17), 1996, pp. 7191-7199
A new method for elucidating elementary reaction steps in zeolite cata
lysis was demonstrated for reactions of isobutene and other monoolefin
s on HZSM5. Radiolysis was used to ''spin label'' reaction products, a
nd EPR was used for product analysis. The evolution of products was re
vealed by quenching the reactions cryogenically in a series of equilib
ration experiments. Isobutene dimerization and isomerization occur on
HZSM5 even at 77 K, and cracking occurs below room temperature. The ra
diolysis/EPR results allow a consistent interpretation of the literatu
re on EPR signals that arise spontaneously upon interaction of acyclic
olefins with air-activated H-Mordenite and HZSM5.