Hydrogen decationated types

As indicated above (Table I), 2- and 3-valent cation forms of mordenite are considerably less active in cyclohexane isomerization than that of hydrogen. It is this property of mordenite-supported catalysts that distinguishes them sharply from zeolites of the faujasite type. Thus, in the case of faujasites, the activity of H-form (decationized form) and 2-valent modifications (such as Ca and Mg ) in acid-base reactions (cracking, isomerization, alkylation) is the same, while H-mordenite is many times as active as any cation form under study. 

Dehydroxylation of decationated mordenite at high temperatures also produces a substantial change in the acidity spectrum as shown in Table VI. Raising the activation temperature of HM zeolites with a Si/AI ratio of about 9.0 from 703 to 1023 K increases the initial differential heat of ammonia adsorption at 573 K from 165 to 180 kJ moP and sharply decreases the concentration of sites near 160-130 kJ mol and the overall acidity (756). IR spectroscopy of molecular hydrogen adsorbed at low temperature showed that mordenite dehydroxylated at 703 K contains only Brpnsted acid sites and nonacidic terminal Si—OH groups, whereas raising the pretreatment temperature decreases the concentration of acidic bridge-type hydroxyl... 

IR studies on the interactions of pyridine with the surface of Y-type decationized zeolite over a wide temperature range indicate the occurrence of a hydrogen bonded MC and hydrogen bonded IP, so possibly... 

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