Deactivation and Reuse of Cesium-Containing Heteropolyacid for the Isomerization of THDCPD

Cesium-containing heteropolyacid, Cs2.5H0.5PW12O40 (CsPW), was used to overcome the environ- mental problems and non-reusability of aluminum chloride for the isomerization reaction of endo-tetrahy- drodicyclopentadiene (endo-THDCPD) to exo-tetrahydrodicyclopentadiene (exo-THDCPD). To increase the reusability of CsPW, a study on the deactivation and regeneration of CsPW catalyst was undertaken. During the reaction, coke formation causes more rapid deactivation of catalyst when compared to that of AlCl3. The removal of coke from the CsPW catalyst was attempted by coke burning out in a muffle furnace. This re- generation allows removal of coke and reuse of the CsPW catalyst, but the acidity and BET surface area de- creased and the isomerization yield was lowered.