Catalytic Reduction of Carbon Dioxide on the (001), (011), and (111) Surfaces of TiC and ZrC: A Computational Study
2022
Silveri, Fabrizio | Quesne, Matthew G. | Viñes, Francesc | Illas, Francesc | Catlow, C. Richard A. | de Leeuw, Nora H.
We present a computational study of the activity and selectivity of early transition-metal carbides as carbon dioxide reduction catalysts. We analyze the effects of the adsorption of CO₂ and H₂ on the (001), (011), and metal-terminated (111) surfaces of TiC and ZrC, as carbon dioxide undergoes either dissociation to CO or hydrogenation to COOH or HCOO. The relative stabilities of the three reduction intermediates and the activation energies for their formation allow the identification of favored pathways on each surface, which are examined as they lead to the release of CO, HCOOH, CH₃OH, and CH₄, thereby also characterizing the activity and selectivity of the two materials. Reaction energetics implicate HCO as the key common intermediate on all surfaces studied and rule out the release of formaldehyde. Surface hydroxylation is shown to be highly selective toward methane production as the formation of methanol is hindered on all surfaces by its barrierless conversion to CO.
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