The Surface Chemistry of 1‐Iodopropane Adsorbed on Pt(111)

On Pt(111) at 110 K, 1‐iodopropane, C 3 H 7 I, adsorbs molecularly, but for doses below 1.7 × 10 14 molecules cm −2 , only H 2 and I appear in thermal desorption. C–I bond cleavage occurs between 160 and 220 K, forming adsorbed n ‐propyl, C (a) H 2 CH 2 CH 3 , and atomic iodine, based on temperature‐programmed desorption (TPD), high‐resolution electron energy loss spectroscopy (HREELS), and X‐ray photoelectron spectroscopy (XPS). n ‐Propyl undergoes β‐hydride elimination forming propylene, with desorption peaks at 185 and 240 K. At 240 K, hydrogenation to propane also occurs. Some di‐σ bonded propylene, C (a) H 2 C (a) HCH 3 , remains at 240 K and it rearranges to propylidyne near 300 K. Atomic H, bound to Pt, recombines and desorbs at ca. 260 K. Further desorption of H 2 is limited by C–H bond breaking and occurs over a broad temperature range with local maxima at ca. 280, 320, and 420 K, typical of propylidyne fragments on Pt. Atomic iodine desorbs in a broad feature at 825 K.