Guanghan Liu#, Shulin Liu#*, Yahan Zhang, Kehui Zhang, Shenghan Gao, Shaopeng Li, Tianjiao Wang, Shaonan Gu, Falu Hu, Guowei Zhou*, Huizhen Liu*

Cite this article: https://doi.org/10.1016/j.cjsc.2026.101113

Publication date:

Keywords: Zn single-atom; C-N bond construction; base-free; microenvironment regulation; intrinsic acid-base synergy

ABSTRACT

Although the construction of C-N bonds via reductive amination of alcohols and amines over non-noble metal single-atom catalysts holds great potential, achieving high activity and selectivity without the addition of a base as an additive remains a significant challenge. The strategy of precisely modifying the local coordination environment of single-atom centers offers a promising opportunity to enhance the intrinsic activity of such catalysts and establish clear structure-activity relationships. Herein, we prepared a series of ZnNC catalysts with tunable coordination numbers. Notably, the ZnNC-900 catalyst, containing a Zn-N4 structure, achieved the 100% conversion and 99% selectivity in the hydrogen transfer reductive amination of alcohols and amines. Mechanism studies revealed that the dehydrogenation of alcohol is the rate-determining step in this tandem reaction. The Zn-N4 coordination structure possesses a lower central charge density and an optimal d-band center energy level, leading to the most favorable acid-base synergy. Furthermore, DFT calculations confirmed that the Zn-N4 structure requires a relatively lower activation energy for the reaction compared to its Zn-N6 counterpart.