Novel high dispersion and high stability cobalt-inlaid carbon sphere catalyst for hydrogen generation from the hydrolysis of sodium borohydride

Abstract

It is noteworthy that a competent catalyst would be conductive to promote the efficiency of hydrogen generation in the hydrolysis of sodium borohydride. However, most current catalysts are suffered from active particle agglomeration or degradation, which are difficult to meet the requirements of continuous and efficient hydrolysis of sodium borohydride to produce hydrogen. Herein, novelly high dispersion and high stability cobalt-inlaid carbon sphere catalysts were prepared using a one-step co-pyrolysis method for the first time. The ultrafine Co nanoparticles are evenly embedded in the carbon spheres by adjusting the synthesis conditions such as amount of ammonia and hydrothermal temperature. As demonstrated, the Co@C-462-145 catalyst (462 μL of ammonia, 145 ℃ of hydrothermal temperature), displayed good catalytic activity for the hydrolysis of sodium borohydride, exhibiting high hydrogen generation rate of 5392 mLH2•min−1•gCo-1 and low Arrhenius activation energies of 32.7 kJ/mol. Significantly, the Co@C-462-145 showed excellent durability retaining 85.2% of initial catalytic activity after five consecutive runs with almost no aggregation and shedding phenomenon. The outstanding catalytic performance of Co@C-462-145 should be attributed to the uniform dispersion and stabilization of the Co nanoparticle. This provides a probable strategy for the preparation of efficient carbon-supported cobalt-based catalysts in the future.