1. Preparation, surface characterization and performance of a Fischer-Tropsch catalyst of cobalt supported on silica nanosprings.
- Author
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Kengne, Blaise-Alexis Fouetio, Alayat, Abdulbaset M., Luo, Guanqun, McDonald, Armando G., Brown, Justin, Smotherman, Hayden, and McIlroy, David N.
- Subjects
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FISCHER-Tropsch process , *COBALT catalysts , *CATALYST supports , *SILICA nanoparticles , *X-ray photoelectron spectroscopy - Abstract
The reduction of cobalt (Co) catalyst supported on silica nanosprings for Fischer-Tropsch synthesis (FTS) has been monitored by X-ray photoelectron spectroscopy (XPS) and compared to FT catalytic activity. The cobalt is present in the starting catalyst as a Co 3 O 4 spinel phase. A two-step reduction of Co 3 O 4 to CoO and then to Co 0 is observed, which is consistent with the results of H 2 -temperature programmed reduction. During the reduction the two steps occur concurrently. The deconvolution of the Co 2p core level state for the catalyst reduced at 385 °C and 1.0 × 10 −6 Torr of H 2 revealed signatures of Co 0 , CoO, and Co 3 O 4 . The reduction saturates at a Co o concentration of approximately 41% after 20 h, which correlates with the activity and lifetime of the catalyst during FTS testing. Conversely, at 680 °C and 10 Torr of H 2 , the catalyst is completely reduced after 10 h. The evolution of the Co d-band at the Fermi level in the valence band XPS spectrum definitively verifies the metallic phase of Co. FTS evaluation of the Co/NS catalyst reduced at 609 °C showed higher production rate (3-fold) of C 6 -C 17 hydrocarbons than the catalyst reduced at 409 °C and is consistent with the XPS analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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