Effect of activation atmosphere in the Fischer–Tropsch Synthesis using a “quasi-model” catalyst of γ-Fe2O3 nanoparticles supported on SBA-15

• Published in: Journal of catalysis Vol. 335; pp. 36 - 46
• Main Authors: Pérez De Berti, Ignacio O., Bengoa, José F., Stewart, Silvana J., Cagnoli, María V., Pecchi, Gina, Marchetti, Sergio G.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.03.2016
• Subjects: Activation atmosphere effect; Fe/SBA-15 system; Fischer–Tropsch Synthesis; Iron oxides nanoparticles; Mössbauer spectroscopy; “Quasi-model” catalysts; Activation atmosphere effect; Fischer–Tropsch Synthesis; Fe/SBA-15 system; Iron oxides nanoparticles; “Quasi-model” catalysts; Mössbauer spectroscopy
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2015.12.004

[Display omitted] •Fe/SBA-15 was activated in H2 or syngas and used as Fischer–Tropsch catalyst.•H2 activation leads to higher CO conversion and higher hydrocarbons production.•H2 activation leads lower methane selectivity.•Pre-synthesized γ-Fe2O3 nanoparticles were used to obtain a “tailored” catalyst. The effect of different activation atmospheres (CO:H2 or pure H2) on activity and selectivity of iron nanoparticles supported on SBA-15 in Fischer–Tropsch Synthesis, has been studied. To achieve this aim a new preparation method, using monodisperse pre-synthesized γ-Fe2O3 nanoparticles of 3nm size, supported on SBA-15, was used. These catalysts have structural properties between real and model catalysts. Therefore, they were named “quasi-model” catalysts. Nanoparticles and catalysts were characterized with several techniques: XRD, N2 adsorption at 77K, magnetic measurements, electron transmission microscopy, Mössbauer spectroscopy between 298 and 13K in air and controlled atmosphere and thermal gravimetric analysis. Catalytic tests showed clearly that activation with pure H2 leads to a catalyst more active and less selective to methane than that activated with CO:H2. To explain these results, different reduction steps were proposed. These different sequences would produce a diverse number of active sites.