Noble-metal-free NiFe nanoparticles immobilized on nano CeZrO2 solid solutions for highly efficient hydrogen production from hydrous hydrazine

Abstract

Hydrous hydrazine (N₂H₄·H₂O) is considered a highly promising liquid chemical hydrogen storage material because of its high hydrogen content (8.0 wt%), simple byproduct (i.e., N₂) and safe handling. In this work, noble-metal-free NiFe nanoparticles (NPs) supported on nano CeZrO₂ solid solutions have been facilely synthesized and successfully applied as a highly efficient catalyst for the rapid and complete decomposition of N₂H₄ in aqueous solution. The turnover frequency (TOF) value of the NiFe/CeZrO₂ catalyst for hydrogen generation from N₂H₄ reached 119.2 h⁻¹ under alkaline conditions at 343 K, which is 28-fold higher than that of the benchmark catalyst, pure NiFe NPs (4.2 h⁻¹). Moreover, the H₂ selectivity and activity show almost no decrease after five runs, indicating that the prepared NiFe/CeZrO₂ catalyst possesses high durability and stability under the current conditions. The high catalytic performance can be attributed to the synergistic electronic effect between NiFe NPs and nano CeZrO₂ solid solutions, as well as small nanoparticles with highly dispersed active sites.