Nanostructured thin-film Co-B catalysts for hydrogen generation from hydrolysis of ammonia borane

Nanostructured thin-film Co-B catalysts were successfully synthesized on Cu sheet by electroless plating for hydrogen generation from catalytic hydrolysis of ammonia borane (NH3BH3). Various pH values were used during the deposition to obtain thin-film Co-B catalysts with small particle size. The as-obtained Co-B samples were characterized by inductively coupled plasma-optical emission spectroscopy (ICP-OES), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the as-prepared Co-B catalyst with smaller particle size displayed high catalytic activity in the hydrolysis of NH3BH3, providing a high hydrogen generation rate of 5500.0 mL min−1 gcat−1 and the lower activation energy of 37.8 kJ mol−1. This enhanced catalytic activity might be attributed to the smaller nanoparticle size and the higher atomic ratio of Co and B, which improved the dispersion of the catalyst efficiently and provided more contact of the active sites on the catalyst surface. Furthermore, the catalytic activity remained about 79.1% of its initial value after 5 cycles, indicating that the thin-film Co-B catalyst was relatively stable in hydrolysis of NH3BH3.