Synthesis, characterization and usage of cobalt and iron based silicate catalysis for production of hydrogen from ammonia

Hydrogen is an important enviromentally friendly alternative energy source which is used in fuel cells especially. The storage and trasportation is important points which researchers fell upon it. The catalytic decomposition of ammonia which has high hydrogen capacity is an important reaction cause there is not any COx by-products. In my thesis study, transition metal ? silicate based nanocomposite porous catalysts to get hydrogen from ammonia with high yield is prepared and related characterization and kinetic studies are carried out. A series of catalysts is prepared by hydrothermal synthesis method with cheap and easy available Co and Fe metals, by using different Co/Si and Fe/Si ratios.The prepared catalysts are tested in a fixed bad flow reactor, between 400 - 750 oC. It is seen that used silicate sources plays an important role on metals dispersion into the catalyst and the activity. All catalysts gave an activity above 500 oC. The most active catalyst is CSAK15 for cobalt catalysts and FSAK05 for iron catalysts. Both gave a %100 conversion at 700oC and relatively high conversions also at lower temperatures. Generally all catalysts gave total conversion above 750 oC. It is determined that KOH usage as a promoter increased the activity for both cobalt and iron catalysts. Using of cobalt asetate as a cobalt precursor increased the activity. Hydrogen reduction time and temperature also effected the activity of the catalysts. Prepared catalysts arestable at 600 oC for 100 min.Keywords : COx free Hydrogen, ammonia decomposition, Co- Silicate Mesoporous Catalysts, Fe-Silicate Mesoporous Catalyst