Facile synthesized Fe nanosheets as superior active catalyst for hydrogen storage in MgH2

Reversible hydrogen storage in MgH2 under mild conditions is a promising way for the realization of "Hydrogen Economy", in which the development of cheap and highly efficient catalysts is the major challenge. Herein, A two-dimensional layered Fe is prepared via a facile wet-chemical ball milling method and has been confirmed to greatly enhance the hydrogen storage performance of MgH2. Minor addition of 5 wt% Fe nanosheets to MgH2 decreases the onset desorption temperature to 182.1 degrees C and enables a quick release of 5.44 wt% H-2 within 10 min at 300 degrees C. Besides, the dehydrogenated sample takes up 6 wt% H-2 in 10 min under a hydrogen pressure of 3.2 MPa at 200 degrees C. With the doping of Fe nano sheets, the apparent activation energy of the dehydrogenation reaction for MgH2 is reduced to 40.7 +/- 1.0 kJ mol(-1). Further ab initio calculations reveal that the presence of Fe extends the Mg-H bond length and reduces its bond strength. We believe that this work would shed light on designing plain metal for catalysis in the area of hydrogen storage and other energy-related issues. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.