Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
68406 | Journal of Molecular Catalysis A: Chemical | 2007 | 6 Pages |
Supported Ru catalysts using MgO, Al2O3 and calcined Mg–Al (2:1) hydrotalcite (HT) with alkali promoter (Cs) were prepared by two different methods viz., the conventional impregnation method and polyol reduction method using ethylene glycol as solvent for obtaining nano-Ru for ammonia synthesis under atmospheric pressure. The catalysts were characterized by XRD, BET surface area, TPR and evaluated for the synthesis of ammonia in the temperature range of 523–698 K at atmospheric pressure. CO chemisorption studies were performed to find out Ru dispersion, particle size and active metal area. The following sequence with respect to the %NH3 (v/v) formation was found: Cs–Ru/HT (ED) > Cs–Ru/HT > Cs–Ru/Al2O3 > Cs–Ru/MgO. The nano-Cs–Ru/HT (ED) catalyst prepared by polyol reduction method showed superior activity over the catalyst prepared from conventional impregnation method. The higher activity of the Cs–Ru/HT (ED) catalyst has been attributed to the presence of highly dispersed nano-particles of Ru as observed from CO chemisorption results and the presence of easily reducible Ru species as observed from TPR studies.
Graphical abstractThe nano-Cs–Ru/HT catalyst prepared by polyol reduction method showed superior ammonia synthesis activity under atmospheric pressure over the catalyst prepared from conventional impregnation method. The higher activity of the Cs–Ru/HT (ED) catalyst has been attributed to the presence of easily reducible Ru species and highly dispersed nano-particles of Ru. Figure optionsDownload full-size imageDownload as PowerPoint slide