Kamel, Mahmoud M., Alhumaimess, Mosaed S., Alotaibi, Mohammad H., Alsohaimi, Ibrahim H., Hassan, Hassan M.A., Alshammari, Hamed M., and Aldosari, Obaid F.
The layered double hydroxide (MgAl-LDH) was modified by manganese for obtaining Mn/MgAl- LDH. The obtained material was characterized by inductively coupled plasma, X-ray powder diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The as-synthesized Mn/MgAl-LDH was investigated for the decomposition and removal of hydrazine in a batch system. Factors affecting the decomposition and removal of hydrazine such as pH, time, initial hydrazine concentration and temperature were optimized. At the optimal pH 8, Mn/MgAl-LDH dose (100 mg), time of 90 min and temperature of 293 K, the hydrazine decomposition and removal percentage was 100% for initial concentrations of 5, 10 and 15 mg L–1. Where, the pure MgAl-LDH showed 14% removal at 90 min for 10 mg L–1of hydrazine compared to Mn/MgAl-LDH. The decomposition of hydrazine increased when the temperature was increased from 293 to 318 K and the time of complete decomposition reduced from 90 to 45 min, respectively. The decomposition process of hydrazine on Mn/MgAl-LDH depended on the formed ions of manganese(II) and (III) as well as Mn3O4on the surface. The existence of Mn3+as a strong oxidant could decompose hydrazine to nitrogen and hydrogen. The catalytic decomposition of hydrazine was best followed by the first-order rate law and the calculated Eavalue was found to be 24.841 kJ mol–1. The simple methodology regarding the material preparation and the method used as well as its effectiveness may provide a promising future for the decomposition and removal of hydrazine.