Facile soft-chemistry synthesis of Co-Ru nanoalloys: influence of the composition on the catalytic activity for the acceptorless dehydrogenation of alcohols.

Abstract

The synthesis of Co-Ru bimetallic nanoparticles was performed by co-reduction of Co(II) and Ru(III) salts in octan-1-ol, acting both as a solvent and a mild reducing agent. The metal composition was varied in the entire range, from pure Co to pure Ru. Although Co and Ru are miscible in the bulk, the formation of nanoalloys is not straightforward and requires selecting carefully reaction parameters such as the nature of the solvent and that of the metal precursors. The formation of nanoalloys was unambiguously evidenced by HAADF STEM–EDX analyses. The particle size and the size dispersity were found to decrease with increasing Ru amount, yielding very small and monodisperse particles for the richest compositions in Ru. The unsupported particles were tested for the acceptorless alcohol dehydrogenation using (±)-octan-2-ol and octan-1-ol as model substrates. The results clearly show a synergetic effect since the bimetallic particles exhibit better performances than their monometallic counterparts.