Two-dimensional C@TiO2/Ti3C2 composite with superior catalytic performance for NaAlH4. (21st August 2020) - Yuan, Zhenluo
Abstract: Carbon coated titanium dioxide supported on two-dimensional titanium carbide (C@TiO2 /Ti3 C2 ) is synthesized by simple annealing under a flowing acetylene (C2 H2 ) atmosphere, and applied to improve the hydriding/dehydriding behavior of sodium alanate (NaAlH4 ). The results indicate that as-prepared C@TiO2 /Ti3 C2 composite exhibits excellent catalytic activity. The initial temperature for hydrogen desorption is reduced by 70 °C compared with the pristine sample. About 4.0 wt% hydrogen is released in 13 min at 140 °C. The apparent activation energies ( E a ) of 10 wt% C@TiO2 /Ti3 C2 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 /Ti3 C2 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. Highlights: 2D C@TiO2 /Ti3 C2 is synthesized by annealing Ti3 C2 MXene under C2 H2 atmosphere. C@TiO2 /Ti3 C2 exhibits superior catalytic activity for hydrogen storage in NaAlH4 . Remarkable improvement in dehydrogenation kinetics and cycling stability of NaAlH4 . Ti-species and carbon contributes to the improved dehydrogenation properties.