The highest catalytic activity in the hydrolysis of ammonia borane by poly(N-vinyl-2-pyrrolidone)-protected palladium-rhodium nanoparticles for hydrogen generation

The use of poly(N-vinyl-2-pyrrolidone)-protected palladium-rhodium nanoparticles (2.5 +/- 1.1 nm) as highly efficient catalysts providing a record catalytic activity in the hydrolysis of ammonia borane for hydrogen generation is reported. They are prepared by co-reduction of palladium and rhodium metal ions in ethanol/water mixture by an alcohol reduction method and characterized by TEM-EDX analysis, UV-Vis spectroscopy, and X-ray photoelectron spectroscopy. They are recyclable and highly efficient catalysts for hydrogen generation from the hydrolysis of ammonia borane even at very low concentrations and temperature, providing record average turnover frequency (1333 mol H-2 (mol cat)(-1) min(-1)), maximum hydrogen generation rate (36,414 L H-2 min(-1) (mol cat)(-1)), and total turnovers (171,000). Poly(N-vinyl-2-pyrrolidone)-protected palladium-rhodium nanoparticles also provide activation energy of 46.1 +/- 2 kJ/mol for the hydrolysis of ammonia borane. (C) 2014 Elsevier B.V. All rights reserved.