Influence of amines in the synthesis and properties of mesostructured aluminas and assessment as supports for Co-based Fischer-Tropsch synthesis catalysts

摘要

The influence of addition of amines (hexylamine, tripropylamine, dodecylamine, and hexadecylamine) and dopants (Zr, Ce) on the properties of mesostructured aluminas (MAs) synthesized using either Tergitol 15-S-9 or Triton X-114 surfactants was investigated. Selected MAs were evaluated as supports for Co and Ru-Co catalysts and their Fischer-Tropsch synthesis (FTS) performance assessed at 493 K, 2.0 MPa, and H-2/CO = 2. The materials were characterized by XRD, N-2 sorption, TG-DTG, EA, XPS, H-2-TPR, H-2 chemisorption, and STEM. Regardless of the surfactant, all amines enlarged the pore size of undoped MAs by ca. 2-3 nm. The impact of amines on BET area and pore volume depended, however, on the surfactant-amine combination and on the presence and concentration of dopants. The Ru-promoted catalyst supported on the MA synthesized with Tergitol-tripropylamine doped with Zr displayed the highest FTS activity and C5+ selectivity due to both high cobalt reducibility and optimum particle size (8 nm).