Microreactors for Syngas Conversion to Higher Alkanes:  Characterization of Sol−Gel-Encapsulated Nanoscale Fe−Co Catalysts in the Microchannels

Abstract

Silicon microreactors have been coated with mixed-metal Fe-Co Fischer-Tropsch catalysts in alumina sol-gel for conversion of syngas (CO + H 2 ) to higher alkanes. Characterization of the nanocatalysts using scanning electron microscopy, energy-dispersive X-ray, atomic force microscopy, and Brunauer-Emmett-Teller surface area measurements, packaging, and the reaction results from a mass spectrometer at controlled temperatures (200-260 °C) and pressure (1 atm) with varying H 2 :CO ratios from 1:1 to 10:1 are described. The catalyst does not adequately infiltrate the 5-µm channels; it coats nicely the 25-µm channels. The initial results are consistent with a lower conversion of CO (∼32%) in a 5-µm-channel reactor and a higher conversion (∼52%) in a 25-µm-channel reactor. The selectivity to propane (∼80%) is not affected by the width of the microchannels. The activity of the sol-gel-encapsulated catalyst before and after the reactions is estimated from its magnetic properties using a vibrating sample magnetometer.

Kinetics of Fischer–Tropsch Synthesis in a 3-D Printed Stainless Steel Microreactor Using Different Mesoporous Silica Supported Co-Ru Catalysts

“…Therefore, the selection of support and study of its interaction with the incorporated metal ion plays an important role in catalysis. In our previous studies, sol-gel encapsulated catalysts were used in silicon microreactors for FT synthesis [37][38][39]. While Al 2 O 3 and SiO 2 sol-gel supports show similar behavior in formation of higher alkanes such as ethane, propane, and butane for the reactions at 1 atm, TiO 2 has a profound effect on FT synthesis [40] and the stability of the catalysts are observed in reverse order from that observed with SiO 2 and Al 2 O 3 .…”

Silica Sol-Gel Supported Nickel Nano-Catalyst for Hydrogen Production Using Microreactors

“…In our previous work, magnetization for ferromagnetic catalysts such as Co and Fe have been used to estimate pure metal percentage from the saturation magnetization value of the ferromagnetic component. 13 The similar procedure was applied to Ni catalyst since Ni is also ferromagnetic. The magnetic behavior of Ni in silica sol-gel after reduction and steam reforming reaction is presented in Figure 4 for micro-and macro-scale reactors.…”

Magnetic Iron Oxide Nanoparticles for Biomedical Applications

“…Slow and controlled speeds of hydrolysis generally lead to the formation of small particles [29]. The factors most likely to influence the kinetics of hydrolysis and condensation are the type of solvent, temperature, nature and concentration of the precursors or the pH [30]. This process of ground-freezing is also an adequate method to future science group synthesize nanoparticles coated in a matrix with silica [31][32][33].…”