Poisoning and non-poisoning oxygen on Cu(410)

Abstract

We have investigated ethene and oxygen co-adsorption on Cu(410) by high resolution electron energy loss spectroscopy. We find that these two species compete for the adsorption sites and that pre-exposure to oxygen affects ethene adsorption more or less strongly depending on oxygen coverage and the kind of occupied sites. The c(2 × 2) O overlayer is inert with respect to ethene adsorption, while when some oxygen is removed by thermally induced subsurface incorporation, ethene chemisorption is restored. The latter species also adsorbs on the disordered oxygen phase formed when O(2) is dosed at low crystal temperature. Contrary to the bare surface case, most of the ethene ends up in a π-bonded configuration. Dehydrogenation occurs, too, albeit as a minority channel. The so-produced carbon reacts already at low temperature with adsorbed oxygen to yield carbon monoxide, which desorbs around 190 K.

First-principles investigation of methanethiol adsorption and dissociation mechanisms on the high-Miller-index vicinal surface Cu(4 1 0)

“…The adsorption on Cu(4 1 0) of various molecular systems from diatomic oxygen [40][41][42][43] and carbon monoxide CO [44] to more complex molecular systems with different chemical functions such as thiol [45,46], disulfide [45], alcohol [47] and alkene [48][49][50] has been investigated by means of powerful experimental tools. In the latter case, experimental and theor etical studies were carried out on the dynamics of ethylene and CO adsorption and decomposition on this surface [44,48,49,51].…”