Comparative Studies of Fischer-Tropsch Synthesis on Iron Catalysts Supported on Al2O3-Cr2O3 (2:1), Multi-Walled Carbon Nanotubes or BEA Zeolite Systems

Abstract

The main goal of the presented paper is to study the influence of a range of support materials, i.e., multi-walled carbon nanotubes (MWCNTs), Al2O3-Cr2O3 (2:1), zeolite β-H and zeolite β-Na on the physicochemical and catalytic properties in Fischer-Tropsch (F-T) synthesis. All tested Fe catalysts were synthesized using the impregnation method. Their physicochemical properties were extensively investigated using various characterization techniques such as the Temperature-Programmed Reduction of hydrogen (TPR-H2), X-ray diffraction, Temperature-Programmed Desorption of ammonia (TPD-NH3), Temperature-Programmed Desorption of carbon dioxide (TPD-CO2), Fourier transform infrared spectrometry (FTIR), Brunauer Emmett Teller method (BET) and Thermogravimetric Differential Analysis coupled with Mass Spectrometer (TG-DTA-MS). Activity tests were performed in F-T synthesis using a high-pressure fixed bed reactor and a gas mixture of H2 and CO (50% CO and 50% H2). The correlation between the physicochemical properties and reactivity in F-T synthesis was determined. The highest activity was from a 40%Fe/Al2O3-Cr2O3 (2:1) system which exhibited 89.9% of CO conversion and 66.6% selectivity toward liquid products. This catalyst also exhibited the lowest acidity, but the highest quantity of iron carbides on its surface. In addition, in the case of iron catalysts supported on MWCNTs or a binary oxide system, the smallest amount of carbon deposit formed on the surface of the catalyst during the F-T process was confirmed.

Novel bimetallic 1%M-Fe/Al2O3-Cr2O3 (2:1) (M = Ru, Au, Pt, Pd) catalysts for Fischer-Tropsch synthesis

“…With a maximum temperature of 430 • C, the second stage presents the reduction of magnetite to metallic iron. The last reduction stage, observed at about 550 • C, is associated with the reduction of spinel phases formed at the stage of the catalyst preparation [5,23,27]. The TPR -H 2 profile recorded for the 1% Ru-40% Fe / Al 2 O 3 -Cr 2 O 3 (2: 1) catalyst showed four reductions stages.…”

“…Fischer-Tropsch (F-T) synthesis is one of the main alternatives to fossil fuels [1][2][3][4][5][6][7]. The advantage of this process is the possibility to obtain clean fuel without sulfur and nitrogen compounds.…”

Outer-Surface Covalent Functionalization of Carbon Nanohorn Spherical Aggregates Assessed by Highly Spatial-Resolved Energy-Dispersive X-ray Spectrometry in Scanning Electron Microscopy

“…Energy-dispersive X-ray spectrometry (EDS) in scanning electron microscopy (SEM) is a powerful tool to evaluate the elemental distribution in various nanomaterials. Because the penetration depth of the incident electron beam ranges from several hundreds of nanometers to several micrometers, the spatial distribution of the elements with the electronic states can be elucidated even inside materials such as metal catalysts , and dopants of CNT bundle structures. In addition, SEM–EDS operates over a wide scanning area from the sub-micrometer to millimeter scale.…”

Editorial: Cobalt and Iron Catalysis

“…[53] (2) Which metals and promoters are most suitable for a specific process, and how do they work together to bring about the desired selectivity? [54][55][56] (3) Which specific reactor configurations and process conditions are superior for targeting specific product ranges? [57][58][59][60] (4) Which processes are involved in catalyst deactivation, which ones dominate, and how can they be managed?…”

“…The importance of cobalt, as a less expensive metal relative to the precious metals, for light-driven water oxidation [68] and electrochemical processes for hydrogen production [69] further highlights the potential of harnessing these metals in a way that benefits society. Regarding current methods that utilize carbon, such as the FTS process, a series of studies included here examine the effect of reaction conditions and promoters [70], investigate the kinetics [53,59,60], and examine the reaction route through computational modeling [71], with the aim of tailoring new formulations in a scientifically-driven manner [55,56,72]. This offers the potential to more effectively utilize the routes that are already available.…”