Comprehensive Density Functional and Kinetic Monte Carlo Study of CO 2 Hydrogenation on a Well-Defined Ni/CeO 2 Model Catalyst: Role of Eley-Rideal Reactions.

Autor: Lozano-Reis P; Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona, Spain., Gamallo P; Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona, Spain., Sayós R; Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona, Spain., Illas F; Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, C. Martí i Franquès 1, 08028 Barcelona, Spain.
Jazyk: angličtina
Zdroj: ACS catalysis [ACS Catal] 2024 Jan 30; Vol. 14 (4), pp. 2284-2299. Date of Electronic Publication: 2024 Jan 30 (Print Publication: 2024).
DOI: 10.1021/acscatal.3c05336
Abstrakt: A detailed multiscale study of the mechanism of CO 2 hydrogenation on a well-defined Ni/CeO 2 model catalyst is reported that couples periodic density functional theory (DFT) calculations with kinetic Monte Carlo (kMC) simulations. The study includes an analysis of the role of Eley-Rideal elementary steps for the water formation step, which are usually neglected on the overall picture of the mechanism, catalytic activity, and selectivity. The DFT calculations for the chosen model consisting of a Ni 4 cluster supported on CeO 2 (111) show large enough adsorption energies along with low energy barriers that suggest this catalyst to be a good option for high selective CO 2 methanation. The kMC simulations results show a synergic effect between the two 3-fold hollow sites of the supported Ni 4 cluster with some elementary reactions dominant in one site, while other reactions prefer the another, nearly equivalent site. This effect is even more evident for the simulations explicitly including Eley-Rideal steps. The kMC simulations reveal that CO is formed via the dissociative pathway of the reverse water-gas shift reaction, while methane is formed via a CO 2 → CO → HCO → CH → CH 2 → CH 3 → CH 4 mechanism. Overall, our results show the importance of including the Eley-Rideal reactions and point to small Ni clusters supported on the CeO 2 (111) surface as potential good catalysts for high selective CO 2 methanation under mild conditions, while very active and selective toward CO formation at higher temperatures.
Competing Interests: The authors declare no competing financial interest.
(© 2024 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
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