Abstract: The temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) were used to study the adsorption and thermal decomposition of 2-iodoethanol on clean Ni(100). The results show that 2-iodoethanol adsorbs molecularly at 100 K in two ways, either just by iodine atom or by both iodine and hydroxyl ends of the molecule. A thermal decomposition starts around 140 K with the production of small amounts of ethylene and water. The bulk of the 2-iodoethanol decomposes at about 150 K via a carbon-iodine scission to form −O(H)CH2CH2− and 2-hydroxyethyl intermediates. Around 160 K the −O(H)CH2CH2− dehydrogenates to an oxametallacycle species (−OCH2CH2−). The two intermediates further decompose to acetaldehyde, at around 210 K and above 250 K, respectively, and some of the acetaldehyde desorbs while the rest decomposes to hydrogen and carbon monoxide.

Key words: 2-iodoethanol, TPD, Ni(100)