Synergistic Catalysis for Dual Enhancement of Synthesis and Hydrogen Storage in NaAlH4 Using a Metallic Al-Ti-Ce Precursor

NaAlH4 suffers from high kinetic barriers, causing high dehydrogenation temperatures, sluggish kinetics, poor reversibility, and low direct synthesis efficiency. Herein, a metallic Al−Ti−Ce alloy ribbon (Ti:Ce = 1:1, total 6 wt %) with a refined Al matrix (∼405 nm) and uniformly dispersed nanoscale Ti2Al20Ce and Al3Ti phases (200−360 nm) was fabricated by arc melting and melt-spinning. Used directly as the Al source, this ribbon enabled successful synthesis of NaAlH4 by ball-milling with NaH under 50 bar H2 for 36 h. The resulting composite delivered a dehydrogenation capacity of 4.73 wt % from 107.4 to 182.1 °C and a capacity retention of 91.98% over 15 cycles. The Ti−Ce synergy refines Al grains and disperses catalytic phases while also improving the hydrogenation and dehydrogenation kinetics of NaAlH4 and suppressing Al agglomeration, collectively ensuring high reactivity and sustained reversibility of the system. This work presents an effective design strategy for an integrated precursor that combines a bimetallic catalyst and an Al source, offering an alternative approach for optimizing the synthesis and hydrogen storage performance of the NaAlH4 system.