Article,
Femtomole adsorption calorimetry on single-crystal surfaces
Chemical reviews, 98 (2): 797-831 (1998)
DOI: 10.1021/cr9700890
Abstract
A unique instrument, a single-crystal adsorption
calorimeter (SCAC), with sensitivity to femtomole
quantities of reacting gas has been developed and
deployed over the past 5 years, providing a significant
new database for surface systems which have been
spectroscopically and structurally well-defined. This
instrument has been used in the first measurements
of heats for molecules that adsorb irreversibly, which
cannot be studied by thermal desorption or isosteric
methods. This is the first comprehensive review of
the instrument and the results obtained. Emphasis
is placed on the extraction of chemisorption bond
energies and interadsorbate lateral interaction energies
from variations in adsorption heat with coverage
obtained for CO, O2, NO, C2H2, C2H4, CO/K, and O2/K
on single crystal surfaces of Ni, Pd, Pt, and Rh. The
data uniquely provide an important benchmark for
theoretical calculations of potential-energy surfaces
for chemisorption, a new thermodynamic criterion for
the onset of nondissociative adsorption (for NO), and
a database for adsorption heats, average bond energies,
and interaction energies for chemisorbed species
on single-crystal surfaces.
Tags
- adsorption;
- carbon-monoxide;
- co
- desorption;
- ethylene
- metal-surfaces;
- molecular-beam;
- no
- oxidation
- pt(110)
- reflection-absorption
- spectroscopy;
- surface;
- temperature-programmed
- thermal-desorption;
