Comparison of Catalytic Behavior of Iridium and Nickel Nanocatalysts for Decomposition of Hydrazine

Abstract

Hydrazine is a useful material in many industries. In many cases, the applications of hydrazine depending on use a suitable catalyst. In the present study, iridium and nickel nanocatalysts on gamma alumina have been synthesized by the impregnation method. The prepared nanocatalysts have been identified using specific surface measurement (BET) and X-ray diffraction (XRD). The catalytic mechanism was also briefly discussed. The catalytic activity was evaluated for hydrazine decomposition in a designed setup at ambient temperature and the products were detected by gas chromatograph. The main goal of this work is prepare, characterize, and comprise the nanocatalytic behaviour of iridium and nickel supported on gamma alumina in decomposition of hydrazine process. The results of this study show that the mechanisms of hydrazine decomposition on Ir and Ni nanocatalysts are different, while hydrazine decomposition leads to NH3 +N2 on Ir surfaces at ambient temperature, N2H4→N2 +H2 pathway is more favourable at Ni surface. The results indicate that at low temperature hydrazine decomposition on Ir first yields NH3 and N2, whereas on Ni nanocatalyst, H2 selectivity can reach more than 90% at low temperature. Regarding to our data, we can proposed Ir/ γ-Al2O3 and Ni/ γ-Al2O3 nanocatalysts for application in monopropellant systems and fuel cells respectively.