Decomposition of cyclopentane on Ni(755): peculiar decomposition behavior of cyclopentane

Decomposition of cyclopentane on Ni(755) and -(111) has been investigated by temperature-programmed desorption (TPD). Adsorption of cyclopentane occurs on both surfaces by a precursor-mediated mechanism. On the (755) surface cyclopentane decomposes almost completely into adsorbed carbon and gaseous hydrogen while heating up from 123 to 573 K. On the contrary, no decomposition occurred on Ni(111). It is concluded that the active sites for the decomposition of cyclopentane are step sites. The decomposition temperature of cyclopentane is noticeably low compared with those of other saturated hydrocarbons, that is n-paraffins (C₅C₈) and cycloparaffins (C₆C₈).