XPS of carbon on Pt-black and EUROPT-1. Is methylcyclopentane ring opening a ‘coke sensitive’ reaction?

Abstract

XPS line decomposition of carbon residues on Pt-black and EUROPT-1 reveal the presence of a graphitic, hydrocarbon polymer and oxidized carbon overlayers on both catalysts. Usual regeneration pretreatment with oxygen and hydrogen at reaction temperatures (ca. 600 K) does not remove all carbon from Pt-black or EUROPT-1 but an O₂ treatment of EUROPT-1 at 673 K removes most of the carbon. A ‘coke sensitivity’ is suggested as an additional factor influencing the ‘selectivity’ (the 2-methylpentane/n-hexane (2MP/nH) ratio) of ring opening of methylcyclopentane, the absence of oxidized carbonaceous entities being necessary to produce low 2MP/nH ratios.