Investigation of the NO + H2 reaction on Pt{100} with low-energy emission and reflection microscopy: PEEM studies

Abstract

Using the technique of photoemission electron microscopy (PEEM) we have examined the reaction between NO and hydrogen on Pt{100} during transient changes in the partial pressures of the reactants. On switching to a hydrogen-rich ambient, reaction–diffusion fronts are formed, the nucleation, velocity and shape of which vary strongly with temperature and the rate of change in partial pressure. Behind the fronts an adsorbate, probably NH₃, produces low workfunction areas on the surface. Below 370 K, however, a different adsorbate, possibly HNO, is formed.