Two-dimensional C@TiO2/Ti3C2 composite with superior catalytic performance for NaAlH4

Carbon coated titanium dioxide supported on two-dimensional titanium carbide (C@TiO2/Ti3C2) is synthesized by simple annealing under a flowing acetylene (C2H2 atmosphere, and applied to improve the hydriding/dehydriding behavior of sodium alanate (NaAlH4). The results indicate that as-prepared C@TiO2/Ti3C2 composite exhibits excellent catalytic activity. The initial temperature for hydrogen desorption is reduced by 70 degrees C compared with the pristine sample. About 4.0 wt% hydrogen is released in 13 min at 140 degrees C. The apparent activation energies (E-a) of 10 wt% C@TiO2/Ti3C2 catalyzing NaAlH4 for the first two-steps dehydrogenation are 72.41 and 64.27 kJ mol(-1) respectively. The structural analyses reveal that C@TiO2/Ti3C2 interacts with NaAlH4 by using ball milling and decomposes to form Ti-species which works in combination with carbon to improve the dehydrogenation performance of NaAlH4. This result provides an important progress in the hydrogen storage of NaAlH4 catalyzed by MXene. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.