CeO x -induced amorphization of CoPt nanoparticles (NPs) is achieved by a facile co-reduction method using sodium borohydride (NaBH 4 ) as the reducing agent at room temperature (298 K) under ambient atmosphere. The investigation results indicate that CeO x plays a critical role in transferring the crystalline CoPt nanoalloy into the amorphous one. To our surprise, the resultant Co 0.65 Pt 0.30 (CeO x ) 0.05 NPs exhibit high catalytic kinetic performance with 72.1% hydrogen (H 2 ) selectivity for the H 2 generation from hydrous hydrazine (N 2 H 4 ) within only a few minute at 298 K. Although complete conversion is not achieved, but the initial turnover frequency value of 194.8 h −1 for the present amorphous catalyst is much higher than that of crystalline one. Moreover, such a highly rapid catalyst may greatly encourage the practical application of hydrous N 2 H 4 as a hydrogen storage material.