Preparation and determination of catalytic activities of group 8 and group 9 metal ion-exchanged zeolite y catalysts in decomposition of nitrous oxide to sole nitrogen and oxygen /

Download
2014
Edinç Cürdaneli, Pelin
The Group 8 and 9 metal(III) ion-exchanged zeolite were prepared from the ion exchange of metal(III) ions with the extra framework Na+ cations of zeolite Y with a Si/Al ratio of 2.5. They were characterized by using inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Group 8 and 9 metal(III) ion-exchanged zeolite materials prepared were tested as catalysts in decomposition of nitrous oxide to oxygen and nitrogen. The catalytic decomposition of nitrous oxide in the presence of metal(III) ion-exchanged zeolite catalyst was carried out in a continuous flow vertical reactor at flow rate of 100 mL/min of 1000 ppm nitrous oxide helium mixture. The catalytic reaction was followed by monitoring the change in concentration of reactant nitrous oxide as well as the products nitrogen and oxygen by gas chromatography. Side products were followed by NOx analyzer. Catalytic activity of ruthenium(III) ion-exchanged zeolite Y is studied depending on the ruthenium loading of zeolite and flow rate of nitrous oxide helium mixture. The results collected reveal that ruthenium(III) ion-exchange zeolite with a ruthenium loading of 3.98wt.% is highly active, long-lived, and reusable catalyst providing 100% conversion of nitrous oxide to sole nitrogen and oxygen at 350 °C without any side reaction. This catalyst can be bottled under ambient conditions and repeatedly used in successive runs of nitrous oxide decomposition for up to five months without significant loss in activity. The other two metals of Group 8, iron(III) and osmium(III) ion-exchanged zeolite Y do not show activity as high as that of ruthenium(III) ion-exchanged zeolite Y in the same reaction. Rhodium(III) ion exchanged zeolite Y (2.12wt.%) gives the highest activity among Group 9 metal ion exchanged zeolite Y catalysts in decomposition of nitrous oxide.
Citation Formats
P. Edinç Cürdaneli, “Preparation and determination of catalytic activities of group 8 and group 9 metal ion-exchanged zeolite y catalysts in decomposition of nitrous oxide to sole nitrogen and oxygen /,” Ph.D. - Doctoral Program, Middle East Technical University, 2014.