Y2O3-functionalized graphene-immobilized Ni–Pt nanoparticles for enhanced hydrous hydrazine and hydrazine borane dehydrogenation

Developing efficient and highly selective catalyst to promote hydrogen generation from hydrous hydrazine (N₂H₄·H₂O) and hydrazine borane (N₂H₄BH₃) remains a challenging issue for fuel cell-based hydrogen economy. In this work, ultrafine and well-dispersed bimetallic NiPt nanoparticles (3.4 nm) were successfully immobilized on Y₂O₃-functionalized graphene (Y₂O₃/rGO) without any surfactant by a simple liquid impregnation approach. It is firstly found that integration of graphene and Y₂O₃ not only can facilitate the formation of ultrafine NiPt nanoparticles (NPs), but also can effectively modulate the electronic structure of NiPt NPs, thereby boosting the catalytic performance. Compared with NiPt/Y₂O₃ and NiPt/rGO, the NiPt/Y₂O₃/rGO nanocomposites (NCs) show remarkable enhanced catalytic efficiency for hydrogen production from N₂H₄·H₂O. In particular, the optimized Ni_0.6Pt_0.4/Y₂O₃/rGO NCs display the best catalytic efficiency and 100% H₂ selectivity for N₂H₄·H₂O dehydrogenation, providing a turnover frequency (TOF) of 2182 h⁻¹ at 323 K, which is among the highest values ever reported. Moreover, the Ni_0.6Pt_0.4/Y₂O₃/rGO NCs also exhibit an excellent catalytic performance (TOF = 3191 h⁻¹) and 100% H₂ selectively for N₂H₄BH₃ dehydrogenation at 323 K. The outstanding catalytic results obtained provide more possibilities for the potential applications of N₂H₄·H₂O and N₂H₄BH₃ as promising chemical hydrogen storage materials.