Studies of acid-base catalyzed reactions. XIV. Isomerization of butene over La2O3 and ZnO

The hydrogenation and isomerization of n-butenes have been studied over ZnO and La2O3. The kinetic data for ZnO showed that 1-butene was the only isomer which hydrogenated at 280C and that the rate of isomerization of 1-butene in the absence of H2 was about equal to the rate of isomerization in the presence of H2 plus the rate of hydrogenation. Moreover, the H2-D2 equilibration reaction was strongly inhibited in the presence of butene. In the absence of hydrocarbon, the time for half-reaction was less than 2 min, whereas in the presence of about 150 Torr of cis-2-butene or 1-butene the half-life times were 59 and 61 min, respectively. For La2O3, hydrogenation of butene did not occur at 600C although C2H4 reacted at room temperature. In isomerization, the initial selectivity of cis-2-butene towards formation of trans-2-butene increased (from nearly zero) with temperature