1. Direct Evidence of Dynamic Metal Support Interactions in Co/TiO 2 Catalysts by Near-Ambient Pressure X-ray Photoelectron Spectroscopy.
- Author
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Salusso D, Scarfiello C, Efimenko A, Pham Minh D, Serp P, Soulantica K, and Zafeiratos S
- Abstract
The interaction between metal particles and the oxide support, the so-called metal-support interaction, plays a critical role in the performance of heterogenous catalysts. Probing the dynamic evolution of these interactions under reactive gas atmospheres is crucial to comprehending the structure-performance relationship and eventually designing new catalysts with enhanced properties. Cobalt supported on TiO
2 (Co/TiO2 ) is an industrially relevant catalyst applied in Fischer-Tropsch synthesis. Although it is widely acknowledged that Co/TiO2 is restructured during the reaction process, little is known about the impact of the specific gas phase environment at the material's surface. The combination of soft and hard X-ray photoemission spectroscopies are used to investigate in situ Co particles supported on pure and NaBH4 -modified TiO2 under H2 , O2 , and CO2 :H2 gas atmospheres. The combination of soft and hard X-ray photoemission methods, which allows for simultaneous probing of the chemical composition of surface and subsurface layers, is one of the study's unique features. It is shown that under H2 , cobalt particles are encapsulated below a stoichiometric TiO2 layer. This arrangement is preserved under CO2 hydrogenation conditions (i.e., CO2 :H2 ), but changes rapidly upon exposure to O2 . The pretreatment of the TiO2 support with NaBH4 affects the surface mobility and prevents TiO2 spillover onto Co particles.- Published
- 2023
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