Active site engineering in NiPt nanoparticles enabling enhanced selective decomposition of hydrous hydrazine

The design of high-performance catalysts for rapid and selective decomposition of hydrous hydrazine (N 2 H 4 ·H 2 O) is crucial for its large-scale application and plays a pivotal role in the future industrial application of hydrogen energy. Here, ultrafine monodispersed NiPt nanoparticles (NPs) confined by P-doped carbon-encapsulated MoC (NiPt/MoC@P–C) are fabricated through a wet-chemical synthesis strategy. The introduction of P and MoC increases the carbon defect content, promoting the adsorption of metal ions and leading to the formation of monodispersed and small-sized NiPt NPs (2.2 nm). Furthermore, the presence of P and MoC also increases the surface electronic density of the catalyst, enhancing the electron density of active centers. Due to these factors, the NiPt NPs in the prepared catalyst possess small particle size, high metal dispersion, and high electron density. Consequently, the optimized Ni 0.5 Pt 0.5 /MoC@P–C exhibits outstanding catalytic performance in achieving the complete dehydrogenation of N 2 H 4 ·H 2 O, with a turnover frequency (TOF) up to 1626 h −1 under alkaline conditions at 323 K. This performance is significantly higher than that of free Ni 0.5 Pt 0.5 NPs (37 h −1 ), Ni 0.5 Pt 0.5 /MoC@C (563 h −1 ), and Ni 0.5 Pt 0.5 /P–C (373 h −1 ), and surpasses almost all reported catalysts for dehydrogenation of N 2 H 4 ·H 2 O. This work proposes an effective strategy for optimizing active centers in the design of high-performance N 2 H 4 dehydrogenation catalysts, offering valuable insights for the development of hydrogen production catalysts for liquid-phase chemical hydrides. • Ultrafine, monodispersed, and electron-rich NiPt NPs confined by MoC@P–C were synthesized. • P and MoC increase carbon defects, enabling smaller NiPt NPs and higher electron density. • NiPt/MoC@P–C shows superior N 2 H 4 dehydrogenation (1626 h −1 ) over NiPt/P–C and NiPt/MoC@. • NiPt/MoC@P–C exhibits lower activation energy (48.1 kJ mol −1 ) than NiPt/MoC@C and NiPt/P–C.