While transition metals are commonly used to catalyze the oxidation of small organic compounds, the mechanisms of these reactions are not yet completely understood. Silver surfaces are important industrial catalysts for the partial oxidation of ethylene to ethylene epoxide and methane to methanol. While significant strides have been taken towards revealing the complex chemical pathways of oxidation reactions by silver surfaces, several aspects of the catalysis, particularly the different ways in which oxygen interacts with the surface and subsurface (near-surface region) of silver have yet to be elucidated. The subtle interplay between surface and subsurface oxygen under different reaction conditions can significantly modify the structure and reactivity of silver. It is this interplay that ultimately forms the catalytically active oxygen-silver species that interacts with the reactants. Furthermore, it is important to know how these active species change with reaction conditions, such as surface temperature and oxygen coverage, so that the conditions can be tuned to design most effective catalysts. In the present study, density functional theory (DFT) was used to investigate the adsorption and kinetics of atomic oxygen at the surface and subsurface of Ag(111) and Ag(110) surfaces, with the goal to investigate the competition between surface and subsurface oxygen at different oxygen coverages, and study their participation in oxidation catalysis by silver surfaces.

Interaction of atomic oxygen with Ag(111) and Ag(110) surfaces: Understanding the role of subsurface oxygen in oxidative catalysis by silver

253rd National Meeting (2017)

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