The nature of crystal facet effect of TiO2-supported Pd/Pt catalysts on selective hydrogenation of cinnamaldehyde: electron transfer process promoted by interfacial oxygen species.
Phys Chem Chem Phys
; 26(27): 18854-18864, 2024 Jul 10.
Article
en En
| MEDLINE
| ID: mdl-38946575
ABSTRACT
Supported noble metal nanocatalysts typically exhibit strong crystal plane dependent catalytic behavior, but their working mechanism is still unclear. Herein, using anatase TiO2 with well-exposed crystal facets of {101}, {100} and {001} as a prototype support, Pd- and Pt-based supported TiO2 nanocatalysts (TiO2-Pd and TiO2-Pt) were prepared by chemical reduction with NaBH4 as reducer, and they showed a distinct metal-dependent crystal facet effect in the selective hydrogenation of cinamaldehyde (CAL). For Pd-based nanocatalysts, most Pd species on the {100} plane of TiO2 are present in the oxidized form with positive charges and unexpectedly show higher reactivity than the Pd species in the zero-valence state on the {101} and {001} planes. On the contrary, Pt species on all three crystal planes of TiO2 show zero-valence state, with relatively low conversion, but much better selectivity for hydrogenation of a CîO bond than Pd-based catalysts. Well-designed experiments manipulating the stability and type of surface oxygen species confirmed that the essence of the crystal facet effect of the catalyst support actually creates a unique nanoconfined interface at the molecular level to construct a surface p-band intermediate state (PBIS), which provides a new alternative channel for surface electron transfer and consequently accelerates the reaction kinetics.
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1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Phys Chem Chem Phys
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
China