Cage formation of N2 under H2O overlayer on Ru(001)

Electron-driven chemistry of halogenated compounds in condensed phases: Effects of solvent matrices on reaction dynamics and kinetics

“…inhibition of Freon desorption by a water ice overlayer) has been observed earlier for halocarbons (CCl 4 [93], CD 3 Cl [113], CF 2 Cl 2 [37]), N 2 [114] and SF 6 [71] under thick water overlayers, where the release of the trapped molecules occurs spontaneously in a very narrow temperature range (several degrees K) corresponding to ASW crystallization. This phenomenon is known as 'molecular volcano' desorption [93].…”

Structure of ice multilayers on metals

“…However, the result would be an upper surface covered by a layer of repulsing dipoles ͑dangling OH͒; moreover very large values would be expected for the work function of a metal surface covered by completely polarized ice multilayers, contrary to experiment. 5,9,18 In simulated relaxed ice bilayers, ferroelectricity in fact decays fast. In the two bilayer and three bilayer PUCKERED models, the dipole of the top bilayer is reduced by a factor of nearly 6 with respect to the first bilayer ͑see Fig.…”

“…The respective M z values for the FLAT model, for one to four bilayers, are 0.56, 0.40, 0.54, and 0.47 D. The relatively modest change of M z with the number of bilayers is qualitatively consistent with the experimentally measured modest variation of of the work function as a function of number of ice bilayers on metals, after the first bilayer. 5,9,18 …”

“…It has been argued that extensive ferroelectric ordering over substantial thickness should be reflected by a very large work function value, contrary to current experimental evidence. 5,9,18 Complete modeling of ice layers on metals requires knowledge of water-water and water-metal interactions; moreover water-water interactions may be modified by the metal. Our objective at this stage is more modest.…”

The Adsorption and Decomposition of C2H4 on Ru(001): A Combined TPR and Work Function Change Study

“…In addition to the "standard" techniques, these open questions can be addressed by employing work function change measurements during adsorption and surface heating (∆Φ-TPD and ∆Φ-TPR modes). Structural rearrangements were observed prior to and during desorption in the case of nonreactive systems (∆Φ-TPD) 11 and decomposition of intermediates in reactive systems (∆Φ-TPR). 12,13 It is known that ethylene rehybridized to a di-σ bonded structure upon adsorption on the Ru (001) surface at 80 K. 4 At a coverage of θ ) C 2 H 4 /Ru (001) ) 0.30 (defined as 1 ML), 80% of the di-σ-bonded ethylene dissociates within the range 150-280 K. The other (20%) desorbs molecularly up to 250 K. 4 Although it is agreed that at higher temperatures ethylene (C 2 H 4 ) irreversibly converts to ethylidine (CCH 3 ), the actual conversion pathway remained controversial.…”