Cu-Promoted Fe₂O₃/MgO-Based Fischer–Tropsch Catalysts of Biomass-Derived Syngas

Abstract

A series of precipitated Fe 2 O 3 /MgO catalysts incorporated with the copper promoter were prepared by the combination of coprecipitation and incipient witness impregnation methods. The catalysts were characterized by N 2 -adsorption-desorption isotherms, Xray diffraction (XRD), H 2 temperature programmed reduction (H 2 -TPR), CO temperature programmed desorption (CO-TPD), O 2 temperature programmed oxidation (O 2 -TPO), laser Raman spectroscopy (LRS), and X-ray absorption near edge structure (XANES). The Fischer-Tropsch (FT) synthesis reaction of the catalysts was also performed in a fixed bed reactor using different H 2 /CO ratios (H 2 /CO = 1 or 2). The characterization results indicated that Mg increases the BET surface area of precipitated oxide precursors by inhibiting sintering during thermal treatment, and leads to the formation of the relatively smaller iron crystallite size. Cu increases the rate of Fe 2 O 3 reduction by providing H 2 dissociation sites. The content of iron carbide phases during TPR process in the synthesis gas increases with the increase of copper content and reaches a maximum for the Cu/Fe atom ratio of 0.02. The optimal catalyst with Cu/Fe = 0.02 has high activity. A maximum in the catalytic activity and methane selectivity was obtained for the synthesis gas ratio of 2 (H 2 /CO = 2).

Characteristics and catalytic properties of Ni/CaAlO x catalyst for hydrogen-enriched syngas production from pyrolysis-steam reforming of biomass sawdust

“…As a versatile building block in the chemical industry and fuel synthesis, synthesis gas (syngas) plays an important role in industry [3][4][5]. Currently, syngas production largely depends on fossil sources through the reforming process [6].…”

Sol–Gel Autocombustion Combined Carbothermal Synthesis of Iron‐Based Catalysts for the Fischer–Tropsch Reaction

“…There is a weak and broad desorption peak centered at 450 °C in the H 2 ‐reduced samples. This is ascribed to strong CO adsorption . The strong CO adsorption indicates the dissociative adsorption of CO, which recombines to desorb at this temperature.…”

“…This is ascribed to strong CO adsorption. [15] The strong CO adsorption indicates the dissociative adsorptiono fC O, which recombines to desorba tt his temperature. This recombination may be surface-adsorbed Ca nd O.…”

Sodium-promoted iron catalysts prepared on different supports for high temperature Fischer–Tropsch synthesis

“…Other promoters such as copper [7,[10][11][12][13][14][15][16], sodium [4,[17][18][19][20][21][22], zinc [10], vanadium [23] and sulfur [20,24] have also been used. It is well-known that sodium addition leads to lower methane selectivity and a significant increase in the olefin-to-paraffin ratio and water-gas shift (WGS) activity [4,17,18].…”

“…This could be a reason why the promotion with sodium and other metals could be more beneficial in some supported catalysts compared to others. The effect of sodium promoter on iron FT catalysts has been previously investigated for silica [11] or alumina supports [13,15]. Recent reports suggest that the FT reaction can be significantly improved by using carbon materials (e.g.…”