Catalytic hydrogenation of phenoxide at room temperature using ultrafine Ru–B amorphous alloy

Abstract

Sodium phenoxide is considered as one of the potentially promising hydrogen storage materials due to its high hydrogen capacity and enhanced thermodynamic properties. However, efficient catalysts are needed to overcome kinetic barriers of the hydrogenation and dehydrogenation processes. In the present work, an ultrafine amorphous Ru–B alloy catalyst was synthesized by a solid-phase ball milling of RuCl3 with NaBH4 and subsequently tested for the hydrogenation of sodium phenoxide in an aqueous solution at room temperature. The conversion of phenoxide is significantly improved by 48.9 % on the Ru3.9B alloy catalyst compared with pristine Ru nanoparticles. Kinetic studies revealed that the hydrogenation of sodium phenoxide is of first-order with respect to H2 pressure and zero-order to the concentration of sodium phenoxide over the Ru3.9B catalyst. Characterizations showed that the electronic structure of Ru is well modulated by B, leading to an electron-rich state of Ru. The highly active catalysis may be due to the fine dispersion, amorphous state, and electron-rich state of Ru in the ultrafine alloy.