Fischer-Tropsch synthesis by reduced graphene oxide nanosheets supported cobalt catalysts: Role of support and metal nanoparticle size on catalyst activity and products selectivity

Natural aluminosilicate nanotubes loaded with RuCo as nanoreactors for Fischer-Tropsch synthesis

Following nanoarchitectural approach, mesoporous halloysite nanotubes with internal surface composed of alumina were loaded with 5-6 nm RuCo nanoparticles by sequential loading/reduction procedure. Ruthenium nanoclusters were loaded inside clay tube by microwave-assisted method followed by cobalt ions electrostatic attraction to ruthenium during wetness impregnation step. Developed nanoreactors with bimetallic RuCo nanoparticles were investigated as catalysts for the Fischer-Tropsch process. The catalyst with 14.3 wt.% of Co and 0.15 wt.% of Ru showed high activity (СO conversion reached 24.6%), low selectivity to methane (11.9%), CO₂ (0.3%), selectivity to C₅₊ hydrocarbons of 79.1% and chain growth index (α) = 0.853. Proposed nanoreactors showed better selectivity to target products combined with high activity in comparison to the similar bimetallic systems supported on synthetic porous materials. It was shown that reducing agent (NaBH₄ or H₂) used to obtain Ru nanoclusters at first synthesis step played a very important role in the reducibility and selectivity of resulting RuCo catalysts.

Studying of the adsorption and diffusion behaviors of methane on graphene oxide by molecular dynamics simulation

In this work, the sorption and diffusion behaviors of the methane on graphene oxide (GO) were investigated by molecular dynamics (MD) simulation. The sorption isotherms at different temperatures were calculated using the Grand Canonical Monte Carlo (GCMC) method and using the Langmuir adsorption model to fit those isotherms. To investigate the effect of the number of graphene oxide layers on the adsorption process, methane adsorption isotherms were calculated for graphene oxide with 1, 2, and 3 layers. The adsorption parameters including Langmuir adsorption constant, the entropy and the enthalpy of adsorption, collision flux, the rate of adsorption, and the rate of desorption were investigated in this work. The highest amount of adsorption calculated is related to graphene oxide three layers. The methane diffusion coefficients and diffusion activation energies were estimated at different temperatures by MD simulation coupled with Einstein relationship. The maximum diffusion coefficient calculated of methane at 348 K was 49 × 10^-10 m²/s.

Oxidative desulfurization of dibenzothiophene via layered graphitic carbon nitride-coordinated transition metal as a catalyst

In this study, graphitic carbon nitride (g-C3N4) has been synthesized. The cobalt-doped (CoO/g-C3N4) samples prepared by the impregnation method and their catalytic property were investigated on the ODS process.