The development of low temperature hydrogen storage system is crucial for the wide application of renewable energy. A key obstacle for this system is the lack of efficient catalysts, in which two-dimensional nanosheets have attracted considerable attention because of their unique properties. Herein, we synthesized graphene-like TiO₂ (B), and applied them as a highly efficient catalyst to dramatically enhance the low temperature hydrogen storage performances of MgH₂. The MgH_2s–TiO₂ (B) quickly absorbs 5.32 and 5.50 wt% H₂ at low temperatures of 50 and 60 °C, respectively, which is superior to most of the previously catalyzed MgH₂ composites. Moreover, MgH₂–TiO₂ (B) begins to desorb hydrogen at ~200 °C and release ~6.29 wt% H₂ below 288 °C. Careful microstructure analyses reveal that TiO₂ (B) nanosheets are reduced to metallic Ti nanoparticles and wrinkled Ti₂O₃ upon ball milling and (de)hydriding processes, which creates lots of boundary interfaces between MgH₂ and Ti-based catalysts, thus facilitating the hydrogen diffusion. Besides, the in-situ formed Ti has the intermediate electronegativity between Mg and H, which could weaken the Mg–H bonds and decrease the dehydrogenation kinetic barriers. While in rehydrogenation, Ti nanoparticles act as effective heterogeneous nucleation agents of MgH₂ nuclei, further promoting hydrogen absorption properties of MgH₂–TiO₂ (B). The present investigation provides clear evidence for remarkable catalytic effect of graphene-like TiO₂ (B) on hydrogen absorption/desorption properties of MgH₂, which is not only important for deeply understanding the mechanism, but also sheds lights for catalysis design towards practical low temperature hydrogen storage.

低温储氢系统的发展对于可再生能源的广泛应用至关重要。该系统的关键障碍是缺乏有效的催化剂，其中二维纳米片由于其独特的性能而引起了相当大的关注。在这里，我们合成了石墨烯状的TiO ₂（B），并将其作为高效催化剂应用，以显着提高MgH _2的低温储氢性能。MgH _2s -TiO ₂（B）在50和60°C的低温下分别快速吸收5.32和5.50 wt％的H ₂，这优于大多数以前催化的MgH ₂复合材料。此外，MgH ₂–TiO ₂（B）在〜200°C时开始脱氢，并在288°C以下释放〜6.29 wt％H ₂。仔细的微观结构分析表明，在球磨和（脱水）过程中，TiO ₂（B）纳米片被还原为金属Ti纳米颗粒和起皱的Ti ₂ O ₃，这在MgH ₂和Ti基催化剂之间产生了许多边界界面，从而促进了氢扩散。此外，原位形成的Ti在Mg和H之间具有中等电负性，这可能削弱Mg-H键并降低脱氢动力学的障碍。在重新氢化过程中，Ti纳米颗粒可作为有效的MgH ₂异质成核剂核，进一步提高了MgH ₂ -TiO ₂（B）的氢吸收性能。本研究为石墨烯样TiO ₂（B）对MgH _2的氢吸收/解吸性能具有显着的催化作用提供了明确的证据，这不仅对于深入了解其机理很重要，而且为催化设计向实用化的低碳化提供了思路。储氢温度。