The development of efficient and scalable catalysts for polyether amine (PEA) synthesis via reductive amination remains an enduring industrial challenge. In this study, bimetallic NiCu alloys supported on amorphous alumina were rationally designed for the amination of low‐molecular‐weight polyether (PPG‐230). The optimized R30%N20%CA catalyst (30% NiO and 20% CuO) calcined at 400°C delivered outstanding performance under mild conditions (180°C, 2 MPa H 2 , and 6.5 h), achieving 76.4% conversion and 99% primary amine selectivity. Characterization revealed that Cu incorporation accelerates Ni reduction, drives NiCu alloy formation, and tunes the electronic environment via electron transfer from Cu to Ni. HRTEM uncovered a Cu‐mediated anisotropic growth mechanism: surface segregation of Cu atoms (driven by lower surface energy) combined with kinetically limited diffusion promotes the formation of high‐aspect‐ratio nanorods with a Ni‐rich core/Cu‐rich shell structure. Reusability tests showed moderate activity decline over five cycles (76.4% ⟶ 61.9% conversion), while selectivity remained > 98%. Deactivation studies (XRD, TEM, and XPS) revealed that thermally activated Cu migrates from the Ni lattice under reaction conditions, causing phase separation, rod fragmentation, particle agglomeration, and pore blockage—a process termed copper segregation–induced alloy disintegration. This structural collapse, accompanied by weakening of Ni–Cu electronic interaction and partial oxidation of exposed Ni 0 sites, accounts for the activity loss. These findings provide both a promising noble‐metal‐free catalyst for PEA production and fundamental insights into alloy stability under operating conditions.
Yu et al. (Thu,) studied this question.