Platinum Nanoparticles Decorated on NaNbO₃ and LiNbO₃ as Catalysts for Enhanced Hydrogen Generation via NaBH₄...

Alkali-metal niobates MNbO₃ (M = Na, Li) decorated with platinum (Pt) nanoparticles (NPs) are innovatively utilized as catalytic supports for hydrogen (H₂) evolution from sodium borohydride (NaBH₄). Notably, a direct comparison between sodium niobate (NaNbO₃) and lithium niobate (LiNbO₃) in their efficiency for H₂ evolution from NaBH₄ was conducted for the first time, highlighting the distinct catalytic performance of these materials. The synthesis was confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The deposited Pt nanoparticles remain below 10 nm. In this study, different transition-metal nanoparticles (M = Co, Ni, Pd, Pt) supported on NaNbO₃ and LiNbO₃ were evaluated as catalysts. The Pt NPs/NaNbO₃ and Pt NPs/LiNbO₃ catalysts demonstrated optimized performance, producing H₂ at similar rates of 2044.9 and 2303.7 mL min^-1 g_cat ^-1 at 293.15 K. Arrhenius plots indicate activation energies (E _a) of 35.54 ± 1.32 kJ mol^-1 for Pt NPs/NaNbO₃ and 35.04 ± 1.32 kJ·mol^-1 for Pt NPs/LiNbO₃. Additionally, the materials exhibited consistent stability, with an efficiency loss of less than 20% after the 10th cycle of use. These results underscore the potential of these catalysts for H₂ generation applications.