Synthesis and characterization of a nanocatalyst consisting of tungsten (VI) oxide and ruthenium for potential use in the hydrogen generation via hydrolysis of methylamine-borane

Abstract

The demand for effective and safe chemical storage systems as an alternative energy carrier is unabated. This study reports the analysis of methylamine-borane (MeAB) as a new, efficient, and widely applicable technological storage material for mobile applications. Here, we report the preparation of tungsten (VI) oxide (WO₃) supported ruthenium (Ru) nanoparticles (Ru/WO₃) by impregnation-reduction method and their use as a nanocatalyst in the hydrolysis of MeAB for hydrogen (H₂) production. Ru/WO₃ nanocatalyst was characterized by a combination of advanced analytical tools such as XRD, XPS, TEM, TEM-EDX, SEM, and SEM-EDX. Ru/WO₃ nanocatalyst, with an average particle size of 2.16 ± 0.23 nm obtained from TEM analysis, produces H₂ at 298 K with an initial turnover frequency (TOF_initial) value of 43.57 min⁻¹ in complete conversion in the hydrolysis of MeAB. In addition, the activation energy (E_a^#), activation enthalpy (ΔH^#) and activation entropy (ΔS^#) values of the Ru/WO₃ nanocatalyst were calculated as in MeAB hydrolysis are 51.54 kJ/mol, 3.7 kJ/mol and 184.57 J/mol × K, respectively, from the Arrhenius and Eyring-Polanyi equations. It was concluded that both the calculated TOF_initial value and activation parameters were quite valuable compared to previous catalysts used for MeAB hydrolysis.