Active sites and their individual turnover frequencies for ethylene hydrogenation on reduced graphene aerogel
Yükleniyor...
Dosyalar
Tarih
2024
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
American Chemical Society
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Graphene aerogel (GA) was reduced at various temperatures to prepare a series of reduced graphene aerogels (rGAs) with different surface characteristics. Detailed characterization demonstrated that an increase in the thermal reduction temperature leads to an increase in surface area accompanied by an increase in surface density of defect sites formed by the removal of the oxygen-containing functional groups. rGA samples were then tested for ethylene hydrogenation under identical conditions. A comparison of catalytic performances of each catalyst demonstrated that the rGA sample prepared by reduction in Ar at 900 °C (rGA-900) provides the highest performance compared with others prepared at lower temperatures. Next, we analyzed the per-gram activity of each catalyst as a sum of individual contributions from different defect sites quantified by Raman spectroscopy and CHNS-O analysis to determine the individual turnover frequencies (TOFs) of each active site. This analysis identified polyene-like structures and interstitial defects associated with amorphous sp2 bonded carbon atoms as the dominant active sites responsible for hydrogenation. A comparison of their TOFs further indicated that the polyene-like structures provide approximately ten times higher TOF compared to those associated with the amorphous carbon defects. These results, identifying the dominant active centers and quantifying their corresponding TOFs, provide opportunities toward the rational design of GA-based carbocatalysts.
Açıklama
Anahtar Kelimeler
Defects, Hydrocarbons, Hydrogenation, Redox reactions, Two dimensional materials
Kaynak
Langmuir
WoS Q Değeri
Scopus Q Değeri
Q1
Cilt
Sayı
Şubat
Künye
Kurtoğlu-Öztulum, Samira F., Yalçın, K., Saraç Öztun, F. E., Kanat, Gizem H., Ünal, U., Uzun, A. (2024). Active sites and their individual turnover frequencies for ethylene hydrogenation on reduced graphene aerogel. Langmuir, Şubat.
