Ruthenium nanoparticles supported on TiO2 (B) nanotubes: Effective catalysts in hydrogen evolution from the hydrolysis of ammonia borane

The release of hydrogen from chemical hydrides is of significant importance for practical applications. In this study, Ru nanoparticles supported on TiO2(B) nanotubes, designated as Ru/TiO2(B), were synthesized and applied as catalysts for hydrogen evolution from the catalytic hydrolysis of ammonia borane (AB) at 25 °C. Results indicate that Ru/TiO2(B) shows high catalytic activity in hydrogen evolution from the hydrolysis of AB with an activation energy of 45.6 kJ mol−1 and a turnover frequency number of 303 mol H2·(mol Ru·min)−1. The Ru/TiO2(B) exhibits a total turnover number of 15,377 in catalytic lifetime measurement in hydrogen generation from the hydrolysis of AB before deactivation. The kinetic studies show that the hydrolysis of AB catalyzed by Ru/TiO2(B) is a first-order reaction with respect to Ru concentration, whereas it is a zero-order reaction regarding the AB concentration. The high catalytic activity of Ru/TiO2(B) demonstrates that TiO2(B) nanotubes are suitable media for nanoparticle immobilization.