In this work, platinum(0) nanoparticles are deposited on the surface of magnetic cobalt ferrite forming magnetically separable Pt-0/CoFe2O4 nanoparticles, which are efficient catalysts in H-2 generation from the hydrolysis of ammonia borane. Catalytic activity of Pt-0/CoFe2O4 nanoparticles decreases with the increasing platinum loading, parallel to the average particle size. Pt-0/CoFe2O4 (0.23% wt. Pt) nanoparticles have an average diameter of 2.30 +/- 0.47 nm and show an extraordinary turnover frequency of 3628 min(-1) in releasing 3.0 equivalent H-2 per mole of ammonia borane from the hydrolysis at 25.0 degrees C. Moreover, the magnetically separable Pt-0/CoFe2O4 nanoparticles possess high reusability retaining 100% of their initial catalytic activity even after ten runs of hydrolysis. The superb catalytic activity and outstanding reusability make the Pt-0/CoFe2O4 nanoparticles very attractive catalysts for the hydrogen generation systems in portable and stationary fuel cell applications. (C) 2021 Elsevier Inc. All rights reserved.