Effect of Preparation Conditions of Fe@SiO Catalyst on Its Structure Using High-Pressure Activity Studies in a 3D-Printed SS Microreactor.

Fischer-Tropsch synthesis (FTS) in a 3D-printed stainless steel (SS) microchannel microreactor was investigated using Fe@SiO catalysts. The catalysts were prepared by two different techniques: one pot (OP) and autoclave (AC). The mesoporous structure of the two catalysts, Fe@SiO (OP) and Fe@SiO (AC), ensured a large contact area between the reactants and the catalyst. They were characterized by N physisorption, H temperature-programmed reduction (H-TPR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron microscopy (XPS), and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) techniques. The AC catalyst had a clear core-shell structure and showed a much greater surface area than that prepared by the OP method. The activities of the catalysts in terms of FTS were studied in the 200-350 °C temperature range at 20-bar pressure with a H/CO molar ratio of 2:1. The Fe@SiO (AC) catalyst showed higher selectivity and higher CO conversion to olefins than Fe@SiO (OP). Stability studies of both catalysts were carried out for 30 h at 320 °C at 20 bar with a feed gas molar ratio of 2:1. The Fe@SiO (AC) catalyst showed higher stability and yielded consistent CO conversion compared to the Fe@SiO (OP) catalyst.