The NO + CO reaction catalyzed by flat, stepped and edged Pd surfaces

The NO + CO reaction catalyzed by flat, stepped and edged Pd surfaces
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by B. Hammer.

J. Catal. **199**, 171 (2001).

Abstract
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The catalytic reduction of NO by CO at Pd surfaces is studied using
density functional theory. The reaction pathways and energy barriers of
the elementary reaction steps are calculated at four different Pd
surfaces; Pd(111), Pd(100), stepped Pd(211), and edged, missing-row
reconstructed Pd(311). The stability of the reaction intermediates,
chemisorbed NO, CO, N2, N, and O varies only moderately with the Pd
surface structure. The energy barriers for the elementary reaction steps
vary, however, more strongly with the Pd structure. The energy barriers
for NO dissociation and for N2 association are found to be much smaller
at palladium steps and edges compared to the values at flat Pd(111) and
Pd(100). For the CO2 formation, steps and edges have little influence on
the energy barrier, reflecting that the flat Pd(100) surface already
contains a very favorable ensemble for the CO2 formation.