Atomistic simulations of surface reactions in ultra-high-temperature ceramics: O2, H2O and CO adsorption and dissociation on ZrB2 (0001) surfaces
Citation:
Zhang, Y., Sanvito, S., Atomistic simulations of surface reactions in ultra-high-temperature ceramics: O2, H2O and CO adsorption and dissociation on ZrB2 (0001) surfaces, arXiv, 2021Download Item:
Abstract:
Understanding surface reactivity is crucial in many fields, going from heterogeneous catalysis to
materials oxidation and corrosion. In order to better decipher the initial stage of surface reactions
of ZrB2 exposed to the harsh environment of aerospace components, the chemical activity of both
Zr- and B-terminated (0001) surfaces is predicted and compared by using state-of-the-art density
functional theory. In particular the adsorption, dissociation and diffusion of O2, CO and H2O
are extensively examined through the calculation of the surface adsorption energies and reaction
pathways. We find the dissociative adsorption of O2 dominating the reactivity of both Zr- and
B-surfaces, while the dissociation of H2O and CO is weakly active on Zr-terminated surfaces, and
even less activated on B-terminated ones. Importantly, we discover that the reaction of O2 and
H2O can trigger surface reconstruction at the B termination, an efficient mechanism for B removal.
Our work thus provides thermodynamic and kinetic insights into the elementary reactions of the
most dominant gases found in the environment typical of aerospace applications, and highlights the
diverse surface reaction mechanisms when ZrB2 exposed to O2, CO and H2O.
Author's Homepage:
http://people.tcd.ie/sanvitosDescription:
PUBLISHED
Author: Sanvito, Stefano
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Journal ArticleCollections
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arXiv;Availability:
Full text availableKeywords:
First-principles calculation, Surface reactions, Dissociation barriers, Surface adsorption, ZrB2DOI:
https://doi.org/10.48550/arXiv.2101.07096Metadata
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