Robust Ru single-atom alloy catalysts coupled with adjacent Fe-site for highly stable ammonia synthesis under mild conditions

Singh, Swati ; Komarala, Eswaravara Prasadarao ; Kim, Seok-Jin ; Yavuz, Cafer T. ; Maghrabi, Louai Mahdi ; Singh, Nirpendra ; Harfouche, Messaoud ; Sebastian, Victor (Universidad de Zaragoza) ; Malina, Ondrej ; Bakandritsos, Aristides ; Anjum, Dalaver Hussain ; AlHammadi, Ali Abdulkareem ; Polychronopoulou, Kyriaki

Resumen: In our pursuit of an efficient catalyst for ammonia production, we developed ruthenium (Ru)-based single atom alloy catalysts on a layered double hydroxide-derived support. The extended X-ray absorption fine structure studies provided evidence of single Ru atoms as a Fe-Ru alloy. High-resolution transmission electron microscopy showcased a larger particle size with higher Ru loading, emphasizing the role of Ru site geometry in catalytic activity. The MgFeOx-0.1Ru catalyst, with optimal Ru dispersion and smaller Fe-Ru particle size (1.6 nm), outperformed other catalysts in NH3 synthesis and demonstrated exceptional stability. Remarkably, the catalyst with 0.1 wt% Ru exhibited superior performance, achieving an exceptional NH3 formation rate of 17,897 µmol g−1 h−1 (at 400 °C, 5 MPa, and Weight hourly space velocity (WHSV) of 50,000 mL g−1 h−1) along with maintaining a consistent NH3 synthesis rate of 7,217 µmol g−1 h−1 (at 400 °C, WHSV of 10,000 mL g−1 h−1, and 5 MPa), for a notable duration of 150 h. Our first-principles calculations show that Ru weakened the binding of both molecular and atomic nitrogen on the catalyst’s surface, facilitating the desorption of N-intermediates. The optimized MgFeOx-0.1Ru catalyst composition with characteristics such as small Fe-Ru alloy particle size and the presence of all active Ru sites on the surface improves lifetime, reducing costs and marking a significant stride towards sustainable and economically viable NH3 production.

Idioma: Inglés

DOI: 10.1016/j.apsusc.2024.161906

Año: 2024

Publicado en: Applied Surface Science 685 (2024), 161906 [16 pp.]
ISSN: 0169-4332

Factor impacto JCR: 6.9 (2024)

Categ. JCR: MATERIALS SCIENCE, COATINGS & FILMS rank: 3 / 23 = 0.13 (2024) - Q1 - T1
Categ. JCR: PHYSICS, CONDENSED MATTER rank: 16 / 79 = 0.203 (2024) - Q1 - T1
Categ. JCR: PHYSICS, APPLIED rank: 33 / 187 = 0.176 (2024) - Q1 - T1
Categ. JCR: CHEMISTRY, PHYSICAL rank: 47 / 185 = 0.254 (2024) - Q2 - T1

Factor impacto SCIMAGO: 1.31 - Chemistry (miscellaneous) (Q1) - Condensed Matter Physics (Q1) - Surfaces, Coatings and Films (Q1) - Surfaces and Interfaces (Q1) - Physics and Astronomy (miscellaneous) (Q1)

Tipo y forma: Article (Published version)

Área (Departamento): Área Ingeniería Química (Dpto. Ing.Quím.Tecnol.Med.Amb.)