Regeneration at room temperature for amorphous NiB/SiO2 catalyst deactivated in cyclopentadiene hydrogenation

The deactivated amorphous NiB/SiO2 catalyst in the selective hydrogenation of cyclopentadiene (CPD) to cyclopentene (CPE) was regenerated by a new met hod, base-wash method at room temperature. The base was alkaline-ethanol so lution. After regeneration, the activity and selectivity were completely re covered. The results of XRD and DSC measurements showed that the amorphous structure of the regenerated amorphous catalyst is almost the same as that of the original counterpart. STEM-EDAX analysis revealed that the surface o f the deactivated catalyst was covered by carbon. After regeneration, the c arbon was removed. BET, H-2 chemisorption and XPS tests indicated that the surface areas and chemical state were held on the renewal catalyst. Such re generation operation can be repeated several times without significant chan ges in the structural and chemical properties. (C) 1999 Elsevier Science B. V. All rights reserved.