Role of water dissociation kinetics on Ni-catalyzed atomic carbon conversion in a steam reforming environment: Which path to take?

Abstract

Various industrial processes such as the steam reforming of hydrocarbons and water-gas shift involve water dissociation as one of their key elementary steps. The preferred reaction paths for these processes can strongly rely on the presence of available OH^* and O^* from water dissociation (asterisk denotes surface bound species), whose coverages are generally temperature dependent. In this work, kinetic Monte Carlo, coupled with density functional theory-based first principles calculations, was used to simulate the kinetics of water dissociation on stepped Ni surface to identify the dominant surface bound water dissociation fragments for a wide range of temperatures. Initial results found that the coverage of OH^* and O^* at relevant temperatures can significantly determine the favorable paths for surface reactions, underscoring the important role of the dominant surface-bound species from water dissociation on reaction selectivity.