Achieving Ultra‐Stable Hydrogen Isotope Separation Over 5000 Cycles With a High‐Loading Pd/Al ₂ O ₃ Composite

ABSTRACT This study successfully prepared a high‐palladium (Pd)‐loading (51 wt%) Pd/Al 2 O 3 composite through multiple wet impregnation. The material exhibited excellent hydrogen isotope separation performance, with metal–support interactions endowing it with a higher plateau pressure and lower desorption temperature. Additionally, the composite demonstrated outstanding long‐term cycling stability, maintaining its capacity over 5000 hydrogen absorption–desorption cycles without degradation. This exceptional cyclability is attributed to the nano‐confinement effect of the Al 2 O 3 support, which effectively suppresses the pulverization of Pd particles and preserves their structural integrity. Overall, these findings highlight the potential of high‐loading Pd/Al 2 O 3 composites as durable and efficient materials for hydrogen isotope separation in nuclear fusion applications.