Modifying the structure of red mud by simple treatments for high and stable performance in COx-free hydrogen production from ammonia
International Journal of Hydrogen Energy, cilt.43, sa.45, ss.20525-20537, 2018 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 43 Sayı: 45
- Basım Tarihi: 2018
- Doi Numarası: 10.1016/j.ijhydene.2018.09.032
- Dergi Adı: International Journal of Hydrogen Energy
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.20525-20537
- Anahtar Kelimeler: Catalytic ammonia decomposition, Hydrogen storage, Iron-based catalyst, Red mud, Valorization of industrial wastes
- Boğaziçi Üniversitesi Adresli: Evet
Özet
Red mud (RM) modified by various treatments was used as a catalyst for ammonia decomposition. Catalytic activity measurements performed at 500 °C and differential conversions illustrated that the rate increases with a decrease in the size of Fe3Ny nanoparticles formed during activation in NH3 flow. Measurements at 700 °C showed that a catalyst prepared by digesting RM in 6 M HCl followed by calcination at 900 °C provides a stable ammonia conversion of 98.8 ± 0.5% for more than 70 h at a space velocity of 120 000 cm3 NH3 h−1 gcat−1. This rate is premier among all iron-based catalysts in terms of both activity and stability and even on par with the performance of other non-noble metal catalysts. Detailed characterization indicated Fe3Ny species readily available on the surface as the active species. Results provided here enable the utilization of RM as an environmentally-friendly, highly efficient, and almost cost-free catalyst for COx-free hydrogen production.