Forming interfacial Li-Ni-Fe hydride enables room-temperature alkyne semi-hydrogenation

Catalytic alkyne semi-hydrogenation is a pivotal industrial transformation currently constrained by the limitations of existing heterogeneous catalysts: precious metals (e.g., Pd) face high costs, while non-precious alternatives (e.g., Ni, Cu, Fe) generally require harsh reaction conditions (100–200 °C, 10–40 bar H 2 ). To address these persistent challenges, we propose a novel strategy integrating alkali metal hydrides, serving simultaneously as hydrogen donors and anionic “ligands” into transition metal systems. Herein, we report a NiFe-LiH composite catalyst that enables efficient and highly selective liquid-phase semi-hydrogenation of alkynes—including aliphatic, aromatic, and heteroatom-substituted substrates under very mild conditions (25 °C, ≤3 bar H 2 ). Mechanistic investigations reveal that reactive hydride species (H − ) are integral to the hydrogenation catalysis. Critically, the formation of unique Li-Ni-Fe-H interfacial species facilitate synergistic interactions wherein anionic hydrides coordinate with transition metals, modulating their electronic states to simultaneously enhance catalytic activity and selectivity. This work demonstrates room-temperature activation and transformation of alkynes enabled by a catalytic Li-Ni-Fe-H system, offering a promising new pathway for developing efficient non-noble metal catalysts for selective hydrogenation reactions.