Hydrolysis of Sodium Borohydride and Ammonia Borane for Hydrogen Generation Using Highly Efficient Poly(n-Vinyl 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 H-2/mol cat.min(-1) and 308 mol H-2/mol cat.min(-1)) and maximum hydrogen generation rates (22,889 L H-2 min(-1) (mol cat)(-1) and 9364 L H-2 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.