Platinyum dimetil siklooktadiyenin resorsinol formaldehit aerojel destek üzerine süperkritik karbon dioksit ortaminda adsorplanmasinin termodinamik ve kinetiği

The thermodynamics and kinetics of adsorption of platinum dimethyl (cyclooctadiene) (PtMe2COD) on resorcinol-formaldehyde aerogel8 (RFA8) from supercritical carbon dioxide was investigated. An experimental technique was developed for the investigation of adsorption kinetics where the supercritical CO2 phase was analyzed directly.In order to investigate the thermodynamics of adsorption, adsorption isotherm of PtMe2COD-scCO2-RFA8 system at 20.7 MPa and 60°C was measured. The adsorption isotherm was represented by Langmuir Model.For the investigation of the kinetics of adsorption, a mass transfer model was developed. It was seen that the model represented the experimental data fairly well with a fitting error of 7.2 %. Spherical RFA8 particles with changing diameters were synthesized in order to investigate the effect of particle size on the adsorption kinetics. It was seen that the time to reach the adsorption equilibrium decreased by decreasing particle size. The effect the model parameter tortuosity on the adsorption kinetics was also investigated. As the model parameter tortuosity decreased, the time to reach equilibrium decreased.In this thesis, Pt nanoparticles supported on RFA8 was also prepared. Effect of metal load on the average particle size of the supported nanoparticles was investigated using XRD measurements. Three different metal loaded 10 wt. %, 22 wt. % and 34 wt % particles were prepared and the average particle sizes were found as 2.3 nm, 3.1 nm and 3.9 nm respectively. It was seen that the average particle sizes increased with increasing metal load.