The superior catalytic effects derived from a 2D Ti₃C₂ (MXene), synthesized by the exfoliation of Ti₃AlC₂ powders, towards the hydrogen storage reaction of MgH₂ were demonstrated. The 5 wt% Ti₃C₂-containing MgH₂ releases 6.2 wt% H₂ within 1 min at 300 °C and absorbs 6.1 wt% H₂ within 30 s at 150 °C, exhibiting excellent dehydrogenation/hydrogenation kinetics.