Dynamics and Site Isolation : Keys to High Propane Dehydrogenation Performance of Silica-Supported PtGa Nanoparticles
Payard, Pierre-Adrien (ETH Zürich. Department of Chemistry and Applied Biosciences)
Rochlitz, L. (ETH Zürich. Department of Chemistry and Applied Biosciences)
Searles, K. (ETH Zürich. Department of Chemistry and Applied Biosciences)
Foppa, Lucas (ETH Zürich. Department of Chemistry and Applied Biosciences)
Leuthold, B. (ETH Zürich. Department of Chemistry and Applied Biosciences)
Safonova, O. V. (Paul Scherrer Institut (Suïssa))
Comas-Vives, Aleix (Universitat Autònoma de Barcelona. Departament de Química)
Copéret, Christophe (ETH Zürich. Department of Chemistry and Applied Biosciences)

Data:	2021
Resum:	Nonoxidative dehydrogenation of light alkanes has seen a renewed interest in recent years. While PtGa systems appear among the most efficient catalyst for this reaction and are now implemented in production plants, the origin of the high catalytic performance in terms of activity, selectivity, and stability in PtGa-based catalysts is largely unknown. Here we use molecular modeling at the DFT level on three different models: (i) periodic surfaces, (ii) clusters using static calculations, and (iii) realistic size silica-supported nanoparticles (1 nm) using molecular dynamics and metadynamics. The combination of the models with experimental data (XAS, TEM) allowed the refinement of the structure of silica-supported PtGa nanoparticles synthesized via surface organometallic chemistry and provided a structure-activity relationship at the molecular level. Using this approach, the key interaction between Pt and Ga was evidenced and analyzed: the presence of Ga increases (i) the interaction between the oxide surface and the nanoparticles, which reduces sintering, (ii) the Pt site isolation, and (iii) the mobility of surface atoms which promotes the high activity, selectivity, and stability of this catalyst. Considering the complete system for modeling that includes the silica support as well as the dynamics of the PtGa nanoparticle is essential to understand the catalytic performances.
Ajuts:	Agencia Estatal de Investigación RyC-2016-19930 Agencia Estatal de Investigación PGC2018-100818-A-I00
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Propane dehydrogenation ; DFT calculations ; Ab initio molecular dynamics ; Metadynamics ; C-H activation
Publicat a:	JACS Au, Vol. 1, Issue 9 (September 2021) , p. 1445-1458, ISSN 2691-3704

DOI: 10.1021/jacsau.1c00212
PMID: 34604854

14 p, 11.0 MB

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