Chemical Thermal Decomposition of 2-iodoethanol on Ni(100)

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 decomposes 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.