Premium
Effect of MgAl 2 O 4 Surface Area on the Structure of Supported Fe and Catalytic Performance in Fischer–Tropsch Synthesis
Author(s) -
Chernavskii Petr A.,
Pankina Galina V.,
Kazantsev Ruslan V.,
Kharlanov Andey N.,
Perfilyev Yuri D.,
Maksimov Sergey V.,
Eliseev Oleg L.
Publication year - 2020
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201901327
Subject(s) - hematite , fischer–tropsch process , catalysis , spinel , magnetite , bet theory , carbide , specific surface area , inorganic chemistry , materials science , chemical engineering , temperature programmed reduction , space velocity , selectivity , fourier transform infrared spectroscopy , chemistry , mineralogy , metallurgy , organic chemistry , engineering
Two MgAl 2 O 4 spinels with low and high surface area are compared as a support for iron Fischer–Tropsch synthesis catalysts. The textural properties of spinels have a great impact on the formation of the active phase and catalytic performance. A well‐crystallized hematite phase is formed on the low surface area spinel ( S BET = 15 m 2 g −1 ), whereas high surface area support ( S BET = 163 m 2 g −1 ) provides highly dispersed or amorphous Fe 2 O 3 . Reducibility of the catalysts in H 2 , CO, and CO/H 2 is investigated by temperature‐programmed reduction (TPR), magnetometry, and diffuse reflectance Fourier‐transform infrared (FTIR) spectroscopy. Adding potassium to the catalyst formulation suppresses the reduction of hematite in magnetite. In synthesis gas atmosphere, the final product of hematite reduction is Hägg carbide, and its amount is higher for the low surface area support. Average carbide particle size correlates with pore diameter of the support. Spinel‐based catalysts possess low selectivity to CO 2 contrary to common iron catalysts. The low surface area spinel affords a very active catalyst with high selectivity to C 5+ hydrocarbons. Hydrogenation of CO over unpromoted iron catalysts seems to be a structure‐insensitive reaction.