In search of the bottlenecks of ammonia synthesis over Ru/Vulcan under ambient conditions
FARADAY DISCUSSIONS, cilt.243, sa.0, ss.164-178, 2023 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 243 Sayı: 0
- Basım Tarihi: 2023
- Doi Numarası: 10.1039/d2fd00173j
- Dergi Adı: FARADAY DISCUSSIONS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Biotechnology Research Abstracts, Chemical Abstracts Core, Compendex, EMBASE, INSPEC, MEDLINE, Metadex
- Sayfa Sayıları: ss.164-178
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
Hydrogenation of the N-N bond under ambient conditions over 1 wt% Ru/Vulcan was monitored through operando Diffuse Reflectance Infrared Spectroscopy (DRIFTS) and DFT. IR signals centered at 3017 cm(-1) and 1302 cm(-1) were visible with attributes similar to the asymmetric stretching and bending vibrations of gas phase ammonia at 3381 cm(-1) and 1650 cm(-1). The intensities of the signals increased with consecutive H-2 : Ar and N-2 flow cycles at room temperature and atmospheric pressure due to accumulation of the formed NHX on the catalyst surface. DFT estimations revealed that a compound with a molecular stoichiometry of N-NH3 can give rise to an IR signal centered at 3051.9 cm(-1). The results of this study, combined with the known vapor liquid phase behavior of ammonia, suggest that under subcritical conditions, the bottlenecks of ammonia synthesis are both N-N bond dissociation and ammonia desorption from the pores of the catalyst.