Hydrous hydrazine (N₂H₄·H₂O) is a water-like liquid with a high hydrogen density (8%, mass fraction), relatively low cost, and satisfactory stability under ambient conditions. Owing to these favorable attributes, N₂H₄·H₂O has attracted considerable attention as a promising hydrogen carrier for onboard or portable applications. The synthesis of highly active and selective catalysts is a central issue in developing practical hydrous hydrazine-based hydrogen generation systems. The development of high-performance catalysts requires fundamental knowledge of the correlation between the surface composition of the catalyst and its catalytic performance. In the present work, a supported Ni-Pt/CeO₂ bimetallic nanocatalyst was prepared by a one-pot co-reduction method, and its use for catalyzing hydrous hydrazine decomposition to generate hydrogen was reported. The surface composition of the Ni-Pt/CeO₂ catalyst was regulated by heat treatments under different atmospheres, such as air, NH₃, H₂, and CO and at different temperatures. It was found that changing the annealing conditions may result in altered Ni/Pt ratio at the catalyst surface, and as a consequence the catalytic performance can be tailored. When the molar Ni/Pt ratio at the catalyst surface was 0.8~1.14, the catalyst has been found to possess remarkable catalytic activity towards hydrous hydrazine decomposition. Additionally, it was found that incorporation of non-metallic N element on the catalyst surface may result in remarkably improved catalytic activity of Ni-Pt/CeO₂ towards hydrous hydrazine decomposition. This finding may open new avenues for the development of high-performance catalyst for promoting hydrogen generation from hydrous hydrazine.