Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2023
Thesis Language: Turkish
Student: Zehra ÖZBEN
Principal Supervisor (For Co-Supervisor Theses): Nuray Oktar
Co-Supervisor: Dilek Varışlı
Abstract:
In this thesis, tungsten and nickel-containing mesoporous catalysts with high catalytic activity were synthesized and their activity tests were carried out of sustainable, clean hydrogen production from ammonia. Tungsten-containing monometallic catalysts synthesized by the sol-gel method and nickel metal at different percentages were loaded into the support structure via impregnation method. In this study, the effect of the support material, the amount of metal loaded on the catalyst structure, the reaction temperature and the heating system used during the catalyst activity tests were investigated. The catalytic activities of the catalysts were carried out in the packed column continuous flow reactor system heated in both conventional and microwave-heated reactor system. Among the monometallic catalysts, 15W-Al2O3 catalyst in the conventional heating system achieved 11% conversion at 750 oC, while 15Ni@Al2O3 catalyst was obtained %99 conversion at 750 oC. In the catalytic activity tests of microwave heating system, complete conversion was achieved at 350 oC, thanks to the ability to give the heat required for the reaction directly to the catalyst, and the formation of hot spots (‘hot spot’) with microwave energy. Prior to activity tests, the syntesized catalysts were characterized by XRD, SEM, XPS and Nitrogen adsorption/desorption analyzes to determine the physical and chemical properties of the prepared materials.
Key Words : Ammonia, hydrogen, tungsten, nickel, carbon, alumina, microwave