One-Pot preparation of recyclable in-situ-generated nano Cu-loaded on Ti3C2 MXene for enhancing MgH2 hydrolysis

Hydrogen production by hydrolysis of hydrogen storage materials is of great importance in real-time hydrogen supply, with MgH₂ being a promising material for hydrogen production. Nevertheless, the fragmented Mg(OH)₂ generated by the hydrolysis of MgH₂ encapsulates the reactants, which inhibits both the reaction rate and extent. In this study, in-situ-generated Cu loaded on Ti₃C₂ MXene (Ti₃C₂-Cu) was incorporated into MgH₂ for the first time by using a simple molten-salt etching method, and it significantly improved the kinetic performance and conversion rate. The MgH₂-5 wt% Ti₃C₂-Cu composite released 1777.1 mL/g H₂ within 35 min at 30°C, with a conversion rate of 95%. Moreover, the Ti₃C₂-Cu catalyst was obtained by simple acid addition and recovery for the first time. The recycled Ti₃C₂-Cu (Ti₃C₂-Cu (Re)) catalyst maintains excellent catalytic activity, and the Ti₃C₂-Cu (Re) used in the 5^th cycle catalyzed MgH₂ to produced 1732.6 mL/g in 35 min. The density functional theory (DFT) calculation demonstrates that the introduction of the Ti₃C₂-Cu accelerates the electron transfer between MgH₂ and Ti₃C₂-Cu, and stretches the Mg-H₁/H₂ bonds. The outstanding hydrolysis performance of the MgH₂-Ti₃C₂-Cu composites is mainly attributed to the layered Ti₃C₂ acting as a proton exchange channel and the dispersed Cu nanoparticles forming more micro protocells with Mg generated by dehydrogenation. This study provides a new catalyst for enhancing the hydrolysis performance of MgH₂ and widens the application of MXene materials.