Modelling atomic layer deposition overcoating formation on a porous heterogeneous catalyst.
Phys Chem Chem Phys
; 24(34): 20506-20516, 2022 Aug 31.
Article
en En
| MEDLINE
| ID: mdl-35993759
ABSTRACT
Atomic layer deposition (ALD) was used to deposit a protective overcoating (Al2O3) on an industrially relevant Co-based Fischer-Tropsch catalyst. A trimethylaluminium/water (TMA/H2O) ALD process was used to prepare â¼0.7-2.2 nm overcoatings on an incipient wetness impregnated Co-Pt/TiO2 catalyst. A diffusion-reaction differential equation model was used to predict precursor transport and the resulting deposited overcoating surface coverage inside a catalyst particle. The model was validated against transmission electron (TEM) and scanning electron (SEM) microscopy studies. The prepared model utilised catalyst physical properties and ALD process parameters to estimate achieved overcoating thickness for 20 and 30 deposition cycles (1.36 and 2.04 nm respectively). The TEM analysis supported these estimates, with 1.29 ± 0.16 and 2.15 ± 0.29 nm average layer thicknesses. In addition to layer thickness estimation, the model was used to predict overcoating penetration into the porous catalyst. The model estimated a penetration depth of â¼19 µm, and cross-sectional scanning electron microscopy supported the prediction with a deepest penetration of 15-18 µm. The model successfully estimated the deepest penetration, however, the microscopy study showed penetration depth fluctuation between 0-18 µm, having an average of 9.6 µm.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Phys Chem Chem Phys
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Finlandia