City Research Online

Abstract

Transition metal exchanged zeolites (prepared by different methods) were characterized using conventional chemical and thermal analyses (TGA, DTA and DSC). Structural stability of the samples was checked by monolayer equivalent surface area (MESA) and X-ray powder diffraction analysis. The catalytic studies of these samples (activated under different atmospheres) were carried out in static or flow systems.

Kinetics of nitrous oxide decomposition reaction were observed on transition metal (cobalt or copper) exchanged 5A zeolites in Pyrex glass static system under vacuum. First order Arrhenius plots for cobalt-5A zeolites were linear over experimental temperature range but deviated from linearity at high temperature for copper-5A zeolites, where it is thought that reaction becomes diffusion limited over 920K.

A copper-glass built flow system (operating at atmospheric pressure) was used for methane oxidation studies on the above cobalt or copper-5A zeolites, and nickel, copper and platinum mordenites (activated under air or nitrogen). Transition metal exchanged -5A zeolites being less reactive for this oxidation reaction, further study was followed on sodium or ammonium forms of nickel and copper mordenites. The catalytic activities of these samples were compared by varying physical parameters like ion exchange, mode of activation, oxygen dilution of the feed (1% methane in air) and/or mode of mixing of the samples. Mixed-catalyst study being a very promising field, can be easily extended by either varying the mixing proportions, oxygen dilution levels, or involving other metal ions or other hydrocarbons as a feed.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > QD Chemistry
Departments:	School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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