The Bronsted acid-catalyzed transformations of cyclic olefins in zeoli
tes HZSM5 and H-mordenite were elucidated by the radiolysis/EPR method
. Products of catalytic reactions were spin-labeled by radiolytic mean
s and identified by using EPR spectroscopy. Comparison of reactions on
HZSM5 and H-mordenite reveals strong shape selectivity on reactions i
n these catalysts. The radiolysis/EPR method is a new in situ spectros
copy with excellent sensitivity and structural specificity for the stu
dy of reaction mechanisms in zeolite catalysts.