A Monte Carlo simulation of the NO+CO reaction on Na-promoted platinum

WILLIAMS, F J; ALDAO, C M; PALERMO, A; LAMBERT, R M

SURFACE SCIENCE

ELSEVIER SCIENCE BV

Año: 1998 vol. 413 p. 174 - 183

0039-6028

An irreversible surface reaction lattice-gas model for the reaction of carbon monoxide and nitric oxide on an Na-modified Pt(111) surface is presented. The effect of Na adatoms on the reaction kinetics is examined in terms of a ‘‘local’’ (i.e. short-range) model for alkali-promoted NO dissociation. Within this framework we also study the effects of extending the range of alkali-induced NO dissociation from nearest neighbour to next nearest neighbour sites. The influence of varying amounts of sodium on overall catalytic activity, reaction kinetics, and on the N2/N2O selectivity are investigated by means of Monte Carlo simulations. It is found that the principal features of recent experimental data involving electrochemical promotion by Na of the CO+NO reaction over Pt are satisfactorily accounted for in terms of this model.