Safe and efficient hydrogen storage remains a grand challenge in the widespread implementation of hydrogen fuel cell technology. Recently, chemical hydrogen storage has emerged as a promising alternative for vehicular and portable applications. A number of hydrogen-rich materials have been experimentally demonstrated to deliver large amounts of hydrogen under mild conditions with controllable kinetics. Among these materials of interest, hydrous hydrazine (N₂H₄H₂O) is a promising but yet not fully explored candidate. The development of highly efficient catalyst and its reaction kinetics law are the key issues of N₂H₄H₂O-based hydrogen generation (HG) systems. Herein, a supported Ni-Pt/La₂O₃ catalyst was prepared by a combination of co-precipitation and galvanic replacement methods. Via optimizing preparing processes, the developed catalyst enabled a complete decomposition of N₂H₄H₂O to generate H₂ at a reaction rate of 340 h^-1 at 323 K, which outperforms most reported N₂H₄H₂O decomposition catalysts. Phase/structural analyses by XRD, TEM and XPS were carried out to gain insight into the catalytic performance of the Ni-Pt/La₂O₃ catalyst. In addition, the effects of temperature, concentration of N₂H₄H₂O and NaOH, and amount of catalyst on the N₂H₄H₂O decomposition were investigated over the Ni-Pt/La₂O₃ catalyst. The kinetic rate equation may be represented by the expression: r = -d[N₂H₄H₂O]/dt = 2435exp(-51.53/(RT))[N₂H₄H₂O]^0.3[NaOH]^0(0.12)[Ni]^1.03. The obtained results should lay the experimental and theoretical foundation for developing practical application of N₂H₄H₂O-based HG system.