Carbon nano-tube coated with iron carbide catalysis for hydrolysis of magnesium to generate hydrogen

Abstract

Hydrolysis of magnesium (Mg) or their composites are considered as an efficient, economical and enabling technique to produce hydrogen (H2). In this study, carbon nano-tube coated with iron carbide (CNT@Fe3C) was synthesized and applied as a catalyst to promote hydrolysis of Mg to generate H2. Ball milling technique was employed to prepare Mg-Xwt%CNT@Fe3C (X = 0.2, 2.0, 5.0 and 10.0) composites for hydrolysis in seawater. Among employed composites, the results demonstrated that the introduction of small amount of CNT@Fe3C promote the hydrolysis kinetics of Mg. Particularly, Mg-5.0 wt%CNT@Fe3C composite ball milled for 1 h released 866.5 mL/g H2 with 10072.0 mLg−1min−1 initial hydrogen generation rate mHGR and demonstrated an excellent composite. Furthermore, activation energy of Mg hydrolysis kinetic dropped to 23.6 kJ/mol. Hence, CNT@Fe3C inhibited the magnesium hydroxide (Mg(OH)2) from sticking to the unreacted Mg surfaces, which enhanced its galvanic corrosion and reactivity. In order to develop portable H2 generators, CNT@Fe3C supported Mg system can provide clean H2 to reduce the adverse environmental effect.