Investigação de catalisadores de ferro suportado em óxido de nióbio dopados com potássio e/ou cobre na reação de Fischer-Tropsch

Abstract

In this study, iron catalysts supported with niobium oxide were created and promoted with potassium and/or copper, with the main goal of measuring the promoter’s structural, textural and electronic effect upon these catalysts in the liquid fuel production by the Fischer-Tropsch Synthesis (FTS). All catalysts were characterized by X-ray Diffraction Powder (XRD), UV-vis Diffuse Reflectance Spectroscopy (DRS-Uv/vis), H2 Temperature Programmed Reduction (H2-TPR), BET Surface Area and Scanning Electron Microscope (MeV) techniques. The catalysts activity was improved by the presence of the promoters, modifying their products selectivity. This way we can select the catalysts in accordance with the mostly desired product formation, whether they are light or heavy hydrocarbons. Catalysts promoted with potassium showed a higher selectivity for developing heavy hydrocarbons whereas the copper catalysts caused the formation of light hydrocarbons. The promoters displayed a high efficiency in developing catalysts with distinct structural, textual and electronic properties, allowing focus on the production of hydrocarbons with different molecular weights by only selecting the catalysts with the proper promoters. Finally, the 10FeNb5Cu and 10FeNb1K catalysts showed a selectivity within the desired range for the FTS, favouring the formation of gasoline (C5-C11) and diesel (C12-C19) carbon chains, respectively.