doi:10.1016/j.apsusc.2024.161906engSingh, SwatiKomarala, Eswaravara PrasadaraoKim, Seok-JinYavuz, Cafer T.Maghrabi, Louai MahdiSingh, NirpendraHarfouche, MessaoudSebastian, VictorMalina, OndrejBakandritsos, AristidesAnjum, Dalaver HussainAlHammadi, Ali AbdulkareemPolychronopoulou, KyriakiRobust Ru single-atom alloy catalysts coupled with adjacent Fe-site for highly stable ammonia synthesis under mild conditionsART-2024-141933In 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.2024http://zaguan.unizar.es/record/14865110.1016/j.apsusc.2024.161906http://zaguan.unizar.es/record/148651oai:zaguan.unizar.es:148651Applied Surface Science 685 (2024), 161906 [16 pp.]All rights reservedhttp://www.europeana.eu/rights/rr-f/info:eu-repo/semantics/closedAccess