Site-resolved hydrogen adsorption on TiFe nanoparticle surfaces and slab models: sequential H2 loading, electronic structure, and thermodynamic screening
International Journal of Hydrogen Energy, cilt.278, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 278
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.ijhydene.2026.157657
- Dergi Adı: International Journal of Hydrogen Energy
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Artic & Antarctic Regions, Chemical Abstracts Core, Chimica, Compendex, Environment Index, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Molecular hydrogen adsorption, SCC-DFTB, Solid-state hydrogen storage, Thermodynamic screening, TiFe intermetallics
- Ankara Üniversitesi Adresli: Evet
Özet
TiFe intermetallics are attractive solid-state hydrogen storage materials, but the atomistic role of nanoscale morphology in H2 adsorption and release remains unclear. Here, self-consistent-charge density-functional tight-binding calculations were used to study H2 adsorption on a 65-atom TiFe nanoparticle Ti33Fe32, benchmarked against TiFe(100) and TiFe(110) slabs. Screening of 134 nanoparticle adsorption minima shows that Fe-containing bridge, hollow-like, and top motifs form a moderate-binding molecular H2 adsorption class, whereas Ti-top sites form a weaker-binding class. Sequential loading up to 48H2 molecules gives a calculated surface-adsorption upper bound of 2.79 wt% H2 for the isolated 65-atom nanoparticle model. Molecular H2 is largely preserved on the nanoparticle, whereas TiFe(100) favors dissociation, with a dissociative preference (ΔE) as low as −2.25 eV. Electronic analysis links this contrast to reduced charge transfer and weaker metal–H hybridization on the nanoparticle. Langmuir–van't Hoff screening identifies Ti-top sites favorable for near-ambient release, providing design guidance for TiFe-based hydrogen storage materials.