Particle size effects in Fischer-Tropsch synthesis by Co catalyst supported on carbon nanotubes

Fischer–Tropsch synthesis using a cobalt catalyst supported on graphitic carbon nitride

The nitrogen atoms in a g-C₃N₄ support improved cobalt reduction in a prepared Co/g-C₃N₄ catalyst.

Surface Decomposition of Dimethyl Methylphosphonate on SnO2 Nanoparticles: Role of Nanoparticle Size

We report the effect of SnO2 particle size on the adsorption behaviour of dimethyl methylphosphonate (DMMP). SnO2 nanoparticles with different particle sizes have been successfully synthesised by the reverse microemulsion method. Transmission electron microscopy and X-ray diffraction results were used to evaluate size distribution, shape and structure of the prepared SnO2 nanoparticles. The infrared spectra of adsorbed DMMP on SnO2 show that the adsorption is dissociative. In addition, it is shown that the size of SnO2 nanoparticles does not affect the reaction mechanism. Adsorption isotherms of DMMP show that by decreasing the size of SnO2 nanoparticles, the amount of DMMP adsorbed is increased. In addition, the calculated heats of adsorption of DMMP are increased as the SnO2 nanoparticle size decreases.

Kinetic Study of Fischer–Tropsch Synthesis Using a Co/CNTs Catalyst

The intrinsic kinetics of the Fischer–Tropsch synthesis reaction in the conversion of synthesis gas into liquid hydrocarbons in a spinning basket reactor over a cobalt catalyst supported on carbon nanotubes were studied. The catalyst was synthesised by the impregnation wetness technique and the reactor tests were done at 215–245 °C, 20 bar, a H2/CO molar ratio of 2 and a gas hourly space velocity of 2.4–12 Nl gcat−1 h−1. To develop an appropriate kinetic model for syngas consumption, five different mechanisms were considered as possibilities for the Fischer–Tropsch reaction, each with a rate-determining step. The rate equations obtained were based on the Langmuir–Hinshelwood–Hougen–Watson model and statistical analyses were used for comparing the resulting values. The activation energies were found to be limited within the range 89–145 kJ mol−1 and the adsorption constants of hydrogen and carbon monoxide were in the range −32 to −76 kJ mol−1 and −13 to −64 kJ mol−1 respectively.