Encapsulation of Ru nanoparticles within NaY zeolite for ammonia decomposition

Abstract

Uniform and minuscule Ru particles confined in NaY zeolite (Ru@NaY) are prepared via a simple in situ synthesis technique. Transmission electron microscopy studies indicate that the Ru particles are encapsulated within the micropores of NaY zeolite and form a uniform size of 1.5–3.5 nm. Thanks to the effective confinement of Ru particles within the NaY zeolite, as well as the high concentration of B-5 sites and basic sites, the prepared Ru@NaY catalysts show excellent NH₃ decomposition activity and highly efficient H₂ formation. Notably, the 0.1Ru@NaY catalyst achieves a 92.7% NH₃ conversion and a H₂ formation rate of 690 mmol min⁻¹·g_Ru⁻¹ at 500 °C and GHSV = 9000 mLNH₃·g_cat⁻¹·h⁻¹ and shows outstanding stability throughout a 95-h lifetime test. The encapsulation synthesis of Ru clusters in zeolites endows the catalysts with exceptional catalytic activities and excellent stability, thus providing new prospects for the production of H₂ from NH₃ decomposition.