Substitution of Co with Ni in Co/Al2O3 Catalysts for Fischer–Tropsch Synthesis
| dc.contributor.author | Martinelli, Michela | |
| dc.contributor.author | Karuturi, Sai Charan | |
| dc.contributor.author | Garcia, Richard | |
| dc.contributor.author | Watson, Caleb D. | |
| dc.contributor.author | Shafer, Wilson D. | |
| dc.contributor.author | Cronauer, Donald C. | |
| dc.contributor.author | Kropf, A. Jeremy | |
| dc.contributor.author | Marshall, Christopher L. | |
| dc.contributor.author | Jacobs, Gary | |
| dc.date.accessioned | 2021-04-19T15:18:54Z | |
| dc.date.available | 2021-04-19T15:18:54Z | |
| dc.date.issued | 2020-03-17 | |
| dc.date.updated | 2021-04-19T15:18:54Z | |
| dc.description.abstract | The effect of cobalt substitution with nickel was investigated for the Fischer–Tropsch synthesis reaction. Catalysts having different Ni/Co ratios were prepared by aqueous incipient wetness co-impregnation, characterized, and tested using a continuously stirred tank reactor (CSTR) for more than 200 h. The addition of nickel did not significantly modify the morphological properties measured. XRD, STEM, and TPR-XANES results showed intimate contact between nickel and cobalt, strongly suggesting the formation of a Co-Ni solid oxide solution in each case. Moreover, TPR-XANES indicated that nickel addition improves the cobalt reducibility. This may be due to H2 dissociation and spillover, but is more likely the results of a chemical effect of intimate contact between Co and Ni resulting in Co-Ni alloying after activation. FTS testing revealed a lower initial activity when nickel was added. However, CO conversion continuously increased with time on-stream until a steady-state value (34%–37% depending on Ni/Co ratio) was achieved, which was very close to the value observed for undoped Co/Al2O3. This trend suggests nickel can stabilize cobalt nanoparticles even at a lower weight percentage of Co. Currently, the cobalt price is 2.13 times the price of nickel. Thus, comparing the activity/price, the catalyst with a Ni/Co ratio of 25/75 has better performance than the unpromoted catalyst. Finally, nickel-promoted catalysts exhibited slightly higher initial selectivity for light hydrocarbons, but this difference typically diminished with time on-stream; once leveling off in conversion was achieved, the C5+ selectivities were similar (≈ 80%) for Ni/Co ratios up to 10/90, and only slightly lower (≈ 77%) at Ni/Co of 25/75. | |
| dc.description.department | Mechanical Engineering | |
| dc.description.department | Biomedical Engineering and Chemical Engineering | |
| dc.identifier | doi: 10.3390/catal10030334 | |
| dc.identifier.citation | Catalysts 10 (3): 334 (2020) | |
| dc.identifier.uri | https://hdl.handle.net/20.500.12588/484 | |
| dc.rights | Attribution 4.0 United States | |
| dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | |
| dc.subject | Fischer–Tropsch synthesis | |
| dc.subject | bimetallic catalyst | |
| dc.subject | cobalt-nickel alloys | |
| dc.subject | TPR-XANES/EXAFS | |
| dc.title | Substitution of Co with Ni in Co/Al2O3 Catalysts for Fischer–Tropsch Synthesis | |
| dc.type | Article |