Single‑Atom‑Induced Electronic Polarization at Adjacent Cluster Promotes Efficient Hydrogen Storage in Magnesium...

Area of Science:

• Materials Science
• Catalysis
• Hydrogen Storage

Background:

• Single-atom/cluster composite catalysts offer unique electronic synergy for heterogeneous catalysis.
• Their role in solid-state hydrogen storage, particularly on magnesium hydride (MgH₂), is not well understood.

Purpose of the Study:

• To investigate the catalytic performance and mechanism of niobium-based single-atom/cluster composite catalysts (Nb_SA/AC) on MgH₂ for hydrogen storage.
• To elucidate the atomic-scale cooperative catalytic mechanism.

Main Methods:

• Construction of a niobium-based single-atom/cluster composite catalyst (Nb_SA/AC) on MgH₂.
• Experimental evaluation of hydrogen release performance.
• Theoretical calculations to reveal the catalytic mechanism.

Main Results:

• Nb_SA/AC enabled MgH₂ to release ~4 wt.% H₂ at 175°C, outperforming individual Nb single-atom and cluster catalysts.
• Theoretical calculations revealed a synergistic mechanism: single atoms regulate electron polarization of adjacent clusters, weakening Mg-H bonds.
• The catalyst demonstrated enhanced dehydrogenation and hydrogenation kinetics.

Conclusions:

• Nb_SA/AC is a highly efficient catalyst for MgH₂ hydrogen storage.
• The study provides the first atomic-scale elucidation of the cooperative catalytic mechanism in single-atom/cluster composites on MgH₂.
• This work offers guidance for designing advanced hydrogen-spillover catalysts.