Study on Anti-poisoning Property and Mechanism of Rare Earth Superlattice Hydrogen Storage Alloys

• • In pure hydrogen, the alloy retains 72.64% capacity after 10 cycles, recovering to 98.27% after 473 K dehydrogenation; after 22 cycles, capacity loss is recoverable, demonstrating inherent cyclability. • • After 10 poisoning cycles, H2S and CO reduce capacity retention to 3.56% and 2.71%, respectively; after 20 cycles, values are 3.68% and 1.73%, indicating severe poisoning with CO being more potent. • • Regeneration at 473 K restores capacity to 40.35% for H2S-poisoned alloy versus 98.27% for CO-poisoned alloy, proving H2S poisoning is largely irreversible while CO is reversible. • • XPS analysis confirms H2S forms CaS and CaSO4 on the surface (irreversible chemical adsorption), whereas CO adsorbs reversibly without new compounds, guiding alloy design to reduce Ca content for enhanced H2S tolerance.