Microwave-Induced Solid-State Interactions for the Synthesis of Fischer-Tropsch Catalysts

Title:Microwave-Induced Solid-State Interactions for the Synthesis of Fischer-Tropsch Catalysts

Volume: 3 Issue: 2

Author(s): Linda Zikhona Linganiso and Mike S. Scurrell

Affiliation:

Keywords: Fischer-Tropsch synthesis, iron, microwave, potassium, SIMS, TPSR.

Abstract: Background: Novel ways of increasing the performance of heterogeneous catalysis are always being sought. Microwave irradiation is one such potential pretreatment method and is expected to be useful in the modification (for better or worse) of iron-based catalysts since the iron oxide precursors are good microwave radiation absorbers.

Methods: Iron based Fischer-Tropsch catalysts were subjected to microwave radiation and their catalytic performance compared with untreated samples. Surface and bulk characterization were carried out in order to try to explain any changes in catalytic behavior observed.

Results: Increases in activity and changes in selectivity (methane, olefins, growth probability, water gas shift contribution) have both been observed and the mode of interaction appears to involve potassium mobilization when added as a promotor, since potassium: silica and potassium: iron surface elemental abundances are changed by the radiative treatment. The surface properties of the catalysts are modified, as detected by the temperature programmed surface reaction (TPSR) of adsorbed carbon monoxide with hydrogen. The TPSR profiles seen are sensitive to both the duration and power level of microwave radiation used.

Conclusion: Microwave radiation can be used to modify the behavior of iron-based catalysts and appears to work by causing changes in the surface rather hen the bulk properties of the solids. Elemental abundances at the surface change as does the chemisorption of carbon monoxide and reactivity of the latter with hydrogen. The effects are easily induced and appear to be long-lived.

Cite this article as:

Linganiso Zikhona Linda and Scurrell S. Mike, Microwave-Induced Solid-State Interactions for the Synthesis of Fischer-Tropsch Catalysts, Current Microwave Chemistry 2016; 3 (2) . https://dx.doi.org/10.2174/2213335602666150817214240