Enhancement of the catalytic performance of silica nanosprings (NS)-supported iron catalyst with copper, molybdenum, cobalt and ruthenium promoters for Fischer-Tropsch synthesis

• Published in: Fuel processing technology 2018-08, Vol.177, p.89-100
• Main Authors: Alayat, Abdulbaset, Echeverria, Elena, Mcllroy, David N., McDonald, Armando G.
• Format: Article
• Language: English
• Subjects: Alkenes; Catalysts; Catalytic activity; Chemical properties; Chemical synthesis; Cobalt; Conversion; Copper; Differential thermal analysis; Differential thermogravimetric analysis; Energy transmission; Fischer-Tropsch process; Fischer-Tropsch synthesis; Gas chromatography; Infrared analysis; Iron; Mass spectrometry; Molybdenum; Nano-catalyst; Organic chemistry; Paraffins; Photoelectrons; Promoters; Ruthenium; Selectivity; Silica nanosprings; Silicon dioxide; X-ray spectroscopy
• ISSN: 0378-3820; 1873-7188
• DOI: 10.1016/j.fuproc.2018.04.020

Iron/nanospring (Fe/NS) catalysts with different metal promoters (Co, Mo, Cu, and Ru) were synthesized via the co-impregnation method and employed to investigate effects of these metals on the physico-chemical properties and catalytic behavior of Fe/NS catalyst during the Fischer-Tropsch synthesis (FTS). The prepared catalysts were characterized before the FTS reaction by various techniques, such as BET surface area, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The FTS performance of the prompted catalysts was examined in a quartz fixed-bed microreactor (H2/CO of 2:1, 230 °C and atmospheric pressure) and the products trapped and analyzed by gas chromatography (GC) and GC-mass spectrometry (GC–MS) to determine CO conversion and reaction selectivity. The characterization results obtained indicated that the promotion of Fe/NS catalyst with Co, Mo, Cu and Ru oxides enhanced the catalytic activity of Fe/NS catalyst. The catalytic performance over Ru-Fe/NS, Co-Fe/NS, Mo-Fe/NS and Cu-Fe/NS catalysts at the same conditions showed that CO conversion was 93.3%, 43.6%, 82.4% and 56.3%, respectively. The C6-C16 liquid hydrocarbon selectivity was 41.1%, 30.1%, 25.4% and 33.8%, respectively. The addition of promoters led to an increase in the selectivity towards olefins instead of aromatics over the non-promoted Fe/NS catalyst. Finally, it was found that the Ru, Co, MO and Cu promoters proved to have a significant effect on selectivity towards desired products namely paraffins and olefins. [Display omitted] •Nanostructured Fe on silica nanospring support were prepared as a Fischer-Tropsch (FT) catalyst.•The addition of Co, Mo, Cu and Ru promoters to Fe influenced FT performance.•Highest FT CO conversion was achieved with Ru as promoter.•Highest C6-C16 hydrocarbon selectivity was achieved with Ru as promoter.