Hydrolysis of Sodium Borohydride and Ammonia Borane for Hydrogen Generation Using Highly Efficient Poly(N-Vinyl-2-Pyrrolidone)-Stabilized Ru–Pd Nanoparticles as Catalysts

Abstract

The catalytic use of highly efficient poly(N-vinyl-2-pyrrolidone)-stabilized Ru–Pd nanoparticles (3.2 ± 1.0 nm) in the hydrolysis of sodium borohydride and ammonia borane is reported. These were prepared by the co-reduction of two metal ions in ethanol/water mixture by the alcohol reduction method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis spectroscopy. These are recyclable and highly active for hydrogen generation from the hydrolysis of sodium borohydride and ammonia borane even at very low concentrations and temperature, providing a record number of average turnover frequency values (762 mol H₂/mol cat.min⁻¹ and 308 mol H₂/mol cat.min⁻¹) and maximum hydrogen generation rates (22,889 L H₂ min⁻¹ (mol cat)⁻¹ and 9364 L H₂ min⁻¹ (mol cat)⁻¹) for sodium borohydride and ammonia borane, respectively. Poly(N-vinyl-2-pyrrolidone)-stabilized Ru–Pd nanoparticles provide activation energies of 52.4 ± 2 and 54.5 ± 2 kJ/mol for the hydrolysis of sodium borohydride and ammonia borane, respectively.

Keywords:

• Ruthenium
• Palladium
• Nanoparticles
• Sodium borohydride
• Ammonia borane

Acknowledgment

The TEM and XPS analyses were carried out at the National High Magnetic Field Laboratory (NHMFL) of Florida State University and Central Laboratory of Middle East Technical University, respectively.