Engineering Ni/NiAlmO heterojunction catalysts for efficient multisite cooperation in the N-alkylation of aniline

Alkylation of amines with alcohols offers a sustainable route featuring high atom economy and minimal waste, yet remains kinetically challenging due to the inertness of alcohols and the need for coordinated activation of multiple sites. In this work, we report a strategy of engineering Ni/NiAl m O heterojunction structure that synergizes Ni 0 and Ni(Al)O sites toward efficient N-alkylation. A series of Ni/NiAl m O catalysts with varied Ni/Al ratios were prepared by coprecipitation and characterized. The results show a gradual evolution of the oxide phase from Ni(Al)O toward NiO with decreasing Al content, with Ni/NiAl 0.5 O exhibiting the most apparent Ni/Ni(Al)O heterojunction and the highest catalytic activity. Density functional theory calculations demonstrate that Ni(Al)O lowers the barrier for O  H cleavage in ethanol relative to NiO, thereby cooperating with Ni 0 sites for subsequent C  H activation. This multisite synergistic strategy provides a new avenue for the rational design and preparation of efficient N-alkylation catalysts.