Coverage dependence of the dynamics of ethylene adsorption on Ag(210)

Abstract

The sticking probability of C 2 H 4 on Ag (210) is studied by the molecular beam technique and by high resolution electron energy loss spectroscopy. At a crystal temperature of 110 K, adsorption occurs initially into a stable, π-bonded, state. At larger coverage a metastable state is populated, too. The sticking probability, S, decreases with increasing translational energy indicating nonactivated adsorption. At low coverage and for impact angles from −60• to +60• , S is angle independent, decreasing only as soon as the (100) nanofacets start to be shadowed. At higher coverage, in contrast, S depends on the impact angle, decreasing markedly for grazing incidence onto the (100) nanoterraces. The saturation coverage corresponds to quarter occupancy of the available step sites.

Dynamics of Ethene Adsorption on Clean and C-Contaminated Cu(410)

“…Outcomes (2) and (3) are expected and have been reported already, e.g., for C 2 H 4 /Ag(410) and C 2 H 4 /Ag(210) . In particular, outcome (2) indicates that an extrinsic precursor is active both at thermal and hyperthermal energy.…”

Bridging the structure gap: Chemistry of nanostructured surfaces at well-defined defects

“…Data taken from Refs. [422,423]. has been developing rapidly in the last years, so that we did not pretend to cover the whole subject.…”

“…The presence of steps significantly enhances the total coverage of chemisorbed ethylene which can be achieved on the surface under UHV conditions: while for Ag(100) Θ ≈ 0.07 ML even when dosing at high translational energy [421], for Ag (410) and Ag(210) a maximum coverage of ≈0.12 ML was attained [422,423]. The fact that a similar coverage is reached for the two stepped surfaces and that its value corresponds to half the nominal density of steps on Ag (410) indicates that sites at adjacent steps cannot be occupied for Ag (210).…”

Adsorption of C2H4 on Stepped Cu(410) Surface: A Combined TPD, FTIR, and DFT Study

“…Studies of C 2 H 4 adsorption on Ag(210) and Ag(410), based on supersonic molecular beam technique, have demonstrated that the sticking probability, measured with the King and Wells technique, is increased on stepped surfaces compared to flat surface, while the achievable maximum coverage is rather independent of the density of steps. 4,5 In this paper, we present the results of the experimental and computational investigation on adsorption of ethylene on Cu(410) and compare them to those obtained on other Cu single crystal surfaces, for example, Cu(210), 6 in order to discuss the effect of step sites on reactivity.…”

“…As for the hydrogenolysis of cyclohexane, a surface with narrower terrace has better reactivity, although the methane dissociation is catalyzed better by a surface with wider terrace. Studies of C 2 H 4 adsorption on Ag(210) and Ag(410), based on supersonic molecular beam technique, have demonstrated that the sticking probability, measured with the King and Wells technique, is increased on stepped surfaces compared to flat surface, while the achievable maximum coverage is rather independent of the density of steps. , …”