ISSN:
1432-0630
Keywords:
82.20Tr
;
82.65Jv
;
82.65Nz
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract The adsorption of H2 and D2 on a Rh (110) surface at 100 K leads to a sequence of ordered phases, among others 1×2 phases atθ H =0.5 and atθ H =1.5 which likely involve a partial surface reconstruction consisting of a small perpendicular displacement of Rh surface atoms. The structure of the adsorbate phases is strongly correlated with the binding energy of the adsorbed phases. Three H (D) binding states (α1,α2 andβ) are populated at saturation as determined by thermal desorption spectroscopy (TDS). Whereas the peak temperature of theβ state is invariant with the hydrogen isotope, the D α1 state appears at a ∼8 Klower and theD α2 state at a ∼5 Khigher temperature than the respective H states. Generally the D phases exhibit a better long-range order than the H phases. The rate of adsorption is identical for the first three adsorbed phases but D2 adsorbs appreciably faster in the 1×2–3H and the final l×1–2H phases. Zero point energy effects as well as a H coverage dependent local interaction model could account for the observed effects.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00617896
Permalink
