Investigation of the stability of platinum clusters and the adsorption of nitrogen monoxide: First principles calculations

Hamad, Bothina; El-Bayyari, Z.; Marashdeh, Ali

doi:10.1016/j.chemphys.2014.07.004

Cited by 13 publications

(8 citation statements)

References 32 publications

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“…While in the most stable adsorption modes, NO interacts with Pt only through the N atom forming one, two, or three Pt–N bonds (structures R (3) in Figure 4), consistent with previous studies, 34,36−40 less stable conformations (structures R (3) ′ in Figure 4) in which O also interacts with Pt are always involved in the pathways for N–O bond dissociation. Such adsorption modes facilitate the transfer of electron density from the metal to the antibonding 2π* orbital of NO, thus weakening the N–O bond and producing an elongation of the optimized NO distance from 1.17 Å in the gas phase to 1.21, 1.29, 1.32, and 1.34 and 1.25 Å on Pt 4 , Pt 10 , Pt 13 , and Pt 38 , and Pt(111) models, respectively.…”

Section: Resultssupporting

confidence: 90%

Low-Temperature Catalytic NO Reduction with CO by Subnanometric Pt Clusters

et al. 2019

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The catalytic subnanometric metal clusters with a few atoms can be regarded as an intermediate state between single atoms and metal nanoparticles (>1 nm). Their molecule-like electronic structures and flexible geometric structures bring rich chemistry and also a different catalytic behavior, in comparison with the single-atom or nanoparticulate counterparts. In this work, by combination of operando IR spectroscopy techniques and electronic structure calculations, we will show a comparative study on Pt catalysts for CO + NO reaction at a very low temperature range (140–200 K). It has been found that single Pt atoms immobilized on MCM-22 zeolite are not stable under reaction conditions and agglomerate into Pt nanoclusters and particles, which are the working active sites for CO + NO reaction. In the case of the catalyst containing Pt nanoparticles (∼2 nm), the oxidation of CO to CO2 occurs in a much lower extension, and Pt nanoparticles become poisoned under reaction conditions because of a strong interaction with CO and NO. Therefore, only subnanometric Pt clusters allow NO dissociation at a low temperature and CO oxidation to occur well on the surface, while CO interaction is weak enough to avoid catalyst poisoning, resulting in a good balance to achieve enhanced catalytic performance.

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Section: Resultssupporting

confidence: 90%

Low-Temperature Catalytic NO Reduction with CO by Subnanometric Pt Clusters

et al. 2019

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“…Note that such a low-symmetry state of the cluster may not correspond to the GS, though it should be near. The structure of Pt n nanoparticles has been studied by different authors − along with characterization of the activities of Pt n to react with N 2 O and CO molecules. − For the GS of the Pt 8 particle, a triple tetragonal pyramid (TTP) form in a triplet state with point group C s was determined . This low-symmetry GS structure of Pt 8 was confirmed in the present study as well as by other authors .…”

Section: Introductionsupporting

confidence: 81%

“…This is important since the cubic form was determined as the lowest energy state for Pt 8 in previous studies. For instance, Xiao and Wang, using a GGA scheme and a pseudopotential with a 5d 10 6s 1 valence space, found a compact cubic O h structure of high spin, 8 μ B , and sides of 2.54 Å. Hamad et al, employing the PBE functional and an ultrasoft pseudopotential, determined a cubic form of 2.54 Å and with 8.14 μ B . We found also at high energy another 3-4-1 structure of high multiplicity, M = 7; this is isomer VI in Figure .…”

Section: Resultsmentioning

confidence: 99%

Catalytic Reduction of Nitrous Oxide by the Low-Symmetry Pt₈ Cluster

et al. 2018

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The search for a catalyst for the reduction of nitrous oxide (NO) is now imperative, as this molecule is a very dangerous pollutant. We found that the low-symmetry Pt cluster presents multiple reaction pathways for NO rupture, which are regioselective. This result was revealed by means of density functional theory calculations within the zero-order-regular approximation, ZORA, explicitly including relativistic effects. It is further proved that Pt is a competitive NO catalyst compared to sub-nanometric rhodium clusters, obtaining similar reaction barriers. The hot adsorption site, a tip atom of Pt, and the rotation of the NO molecule over the metallic cluster promote the formation of a frustrated bridge activated transition state, Pt-NO. This transition structure yields to spontaneous dissociation of NO without bridge formation. Along this catalytic process, rearrangements within the metal cluster take place, preserving its stability. Moreover, in addition to being important attributes of the Pt particle in the NO reduction, fluxionality and multiple reaction pathways may also prevent poisoning effects. Overall, this differs from reported results for more symmetric metal particles also used as catalysts.

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“…Heredia, (Heredia, et al, 2012), Hamad (Hamad, et al, 2014) y Li, (Li, Odunlami & Carbonnière, 2017), propusieron diferentes combinaciones de funcional/base, programas de cómputo y analizaron el efecto de la multiplicidad, concluyendo que en la mayoría de los cúmulos de Ptn donde n<12 las conformaciones obtenidas prevalecen, mientras que para los de mayor tamaño (n>12) existen discrepancias.…”

Section: Platinounclassified

Estudio TFD de cúmulos de Pt-Ir con geometría prisma triangular

Rangel-Peña

Zárate-Hernández

Camacho-Mendoza

et al. 2021

ICBI

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En este trabajo, se presenta un estudio sistemático de las propiedades estructurales y electrónicas de cúmulos bimetálicos de Pt6−nIrn donde n = [0 – 6] usando la metodología B3LYP/LanL2DZ en el contexto de la teoría de los funcionales de la densidad (TFD). Las estructuras de los cúmulos puros Pt6 e Ir6 muestran arreglos tridimensionales altamente estables con multiplicidades electrónicas (μ) entre 7 y 13. El cúmulo puro de Pt6 más estable adopta una geometría de prisma triangular. Para la evaluación de los cúmulos dopados Pt6−nIrn (n = [0 – 6]) se determinó la longitud de enlace promedio, las cargas de Mulliken, los orbitales moleculares frontera y el mapeo del potencial electrostático. La evaluación de las propiedades electrónicas y estructurales demuestra que la incorporación de átomos de iridio en cúmulos de platino modifica su reactividad.

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Investigation of the stability of platinum clusters and the adsorption of nitrogen monoxide: First principles calculations

Cited by 13 publications

References 32 publications

Low-Temperature Catalytic NO Reduction with CO by Subnanometric Pt Clusters

Low-Temperature Catalytic NO Reduction with CO by Subnanometric Pt Clusters

Catalytic Reduction of Nitrous Oxide by the Low-Symmetry Pt₈ Cluster

Estudio TFD de cúmulos de Pt-Ir con geometría prisma triangular

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Investigation of the stability of platinum clusters and the adsorption of nitrogen monoxide: First principles calculations

Cited by 13 publications

References 32 publications

Low-Temperature Catalytic NO Reduction with CO by Subnanometric Pt Clusters

Low-Temperature Catalytic NO Reduction with CO by Subnanometric Pt Clusters

Catalytic Reduction of Nitrous Oxide by the Low-Symmetry Pt8 Cluster

Estudio TFD de cúmulos de Pt-Ir con geometría prisma triangular

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Catalytic Reduction of Nitrous Oxide by the Low-Symmetry Pt₈ Cluster