Enhanced Fischer–Tropsch activity on Co/P–Al2O3 catalyst: Effect of phosphorous content

Effects of phosphorus and saccharide on size, shape, and reducibility of Fischer–Tropsch catalysts for slurry phase and fixed-bed reactions

“…At y = 0.1, as the amount of P increased, the DR decreased slightly at x = 0.5, and then increased at x = 1, while the dispersion moved oppositely. The behaviors of these catalysts, P(x)S(0.1), appeared very similar to those in our previous work [10]. At y = 0.2, the dispersion did not change significantly, but the DR decreased as the amount of P increased, which is the opposite movement to P(x)S(0).…”

“…3a and Table 1, it was found that the addition of P alleviated the interaction between the catalyst and the support, increasing the DR while decreasing the dispersion. In the previous work [10] shown in Fig. 3b, however, with up to 2 wt% P in high-surface-area alumina, the DR decreased while the dispersion did not significantly change, except for P(2), and C 5+ productivity almost doubled.…”

“…According to Riad [28], the band at 1971 cm −1 is an indication of the vibrational structural modes of boehmite, and the band at around 914 cm −1 is due to a vibrational mode localized in the surface layer of boehmite and most likely involving deformation of surface hydroxyl group. The spectra of all the P-modified catalysts exhibited bands due to the P O stretching vibration of the PO 4 3− tetrahedra near 1100-1170 cm −1 , indicating the generation of an AlPO 4 phase on the surface [10,[29][30][31]. However, it should be noted that the bands of P(0) at around 914-1117 cm −1 were not confused with the triply degenerate P O stretching vibration band since the shape of peak looked different from those of the others.…”

“…The catalysts (0.3 g) with ␣-Al 2 O 3 (1.5 g) were previously reduced in situ at 400 • C for 12 h under a flowing 5% H 2 /He reduction gas mixture at SV = 5000 mL/g cat /h. The activity tests were conducted for 120 h under the following reaction conditions: T = 220 • C, P = 2.0 MPa (gage), SV = 2000 mL/g cat /h, feed composition of H 2 /CO/CO 2 /Ar (mol%) = 57.3/28.4/9.3/5.0, where Ar was used as the internal standard for GC analysis [10,18].…”

“…Our interest lies in the effects of the surface characteristics of supports and the morphology of cobalt crystals on the performance of cobalt-based FTS. In our previous work, the effect of phosphorus modification on alumina was examined in a fixed-bed reactor (FBR) [10]. We found that the high FTS activity and stability were mainly attributable to the good dispersion and homogeneous distribution of cobalt species with high reducibility.…”