XPS OF CARBON ON PT-BLACK AND EUROPT-1 - IS METHYLCYCLOPENTANE RING-OPENING A COKE SENSITIVE REACTION

XPS line decomposition of carbon residues on Pt-black and EUROPT-1 rev eal the presence of a graphitic, hydrocarbon polymer and oxidized carb on overlayers on both catalysts. Usual regeneration pretreatment with oxygen and hydrogen at reaction temperatures (ca. 600 K) does not remo ve all carbon from Pt-black or EUROPT-1 but an O-2 treatment of EUROPT -1 at 673 K removes most of the carbon. A 'coke sensitivity' is sugges ted as an additional factor influencing the 'selectivity' (the 2-methy lpentane/n-hexane (2MP/nH) ratio) of ring opening of methylcyclopentan e, the absence of oxidized carbonaceous entities being necessary to pr oduce low 2MP/nH ratios.