title: Synthesis of Ni-Ru alloy nanoparticles and their high catalytic activity in dehydrogenation of ammonia borane.
abstract: We report the synthesis and characterization of new Ni(x)Ru(1-x) (x = 0.56-0.74) alloy nanoparticles (NPs) and their catalytic activity for hydrogen release in the ammonia borane hydrolysis process. The alloy NPs were obtained by wet-chemistry method using a rapid lithium triethylborohydride reduction of Ni(2+) and Ru(3+) precursors in oleylamine. The nature of each alloy sample was fully characterized by TEM, XRD, energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). We found that the as-prepared Ni-Ru alloy NPs exhibited exceptional catalytic activity for the ammonia borane hydrolysis reaction for hydrogen release. All Ni-Ru alloy NPs, and in particular the Ni(0.74)Ru(0.26) sample, outperform the activity of similar size monometallic Ni and Ru NPs, and even of Ni@Ru core-shell NPs. The hydrolysis activation energy for the Ni(0.74)Ru(0.26) alloy catalyst was measured to be approximately 37 kJ mol(-1). This value is considerably lower than the values measured for monometallic Ni (≈70 kJ mol(-1)) and Ru NPs (≈49 kJ mol(-1)), and for Ni@Ru (≈44 kJ mol(-1)), and is also lower than the values of most noble-metal-containing bimetallic NPs reported in the literature. Thus, a remarkable improvement of catalytic activity of Ru in the dehydrogenation of ammonia borane was obtained by alloying Ru with a Ni, which is a relatively cheap metal.
authors.affiliation: Institut national de la recherché scientifique 1650, boulevard Lionel-Boulet, Varennes, Quebec, J3X 1S2, Canada. chen@emt.inrs.ca
authors.forename: Guozhu
authors.initials: G
authors.lastname: Chen
authors.forename: Stefano
authors.initials: S
authors.lastname: Desinan
authors.forename: Renzo
authors.initials: R
authors.lastname: Rosei
authors.forename: Federico
authors.initials: F
authors.lastname: Rosei
authors.forename: Dongling
authors.initials: D
authors.lastname: Ma