Structurally ordered <scp> Ni ₃ Sn ₂ </scp> intermetallic catalyst with well‐tuned Ni sites for propyne semihydrogenation

Abstract Selective hydrogenation of propyne is essential for producing polymer‐grade propylene, yet achieving high selectivity with non‐precious metal catalysts remains challenging. Here, we report a structurally ordered Ni 3 Sn 2 intermetallic catalyst synthesized via topological transformation of NiSn(OH) 6 @Ni/Mg/Al layered double hydroxides. Structural characterization using X‐ray diffraction, high‐resolution transmission electron microscopy, and X‐ray absorption spectroscopy confirms the formation of the hexagonal Ni 3 Sn 2 intermetallic phase, featuring atomically ordered and electronically modulated Ni 1 Sn 2 ensemble sites. The catalyst delivers 98.50% propylene selectivity at near‐complete propyne conversion, markedly outperforming the Ni, Ni 3 Sn, and Ni 3 Sn 4 reference catalysts. Mechanistic insights from temperature‐programmed surface reactions and density functional theory calculations elucidate that the superior performance arises from moderate σ‐type propyne adsorption and kinetically favored propylene desorption on Ni 1 Sn 2 ensemble sites. This work demonstrates a rational intermetallic design strategy for developing high‐performance, non‐noble metal catalysts through precise control of active site geometry and electronic structure.