Magnetically recyclable synergistic Co–Zn dual-atom carbon catalyst for selective hydrogenation of nitroarenes under mild conditions

Low-temperature pyrolysis at 700°C retains atomically dispersed Zn species. • The preferential role of Co–N 4 toward H 2 dissociation versus Zn–N 4 toward –NO 2 adsorption in dual-atomic sites. • Co 1 Zn 1 @NC shows exceptional selectivity and stability for nitroarene hydrogenation. • The catalyst can be magnetically recycled and reused for multiple cycles. The selective hydrogenation of nitroarenes to anilines is a cornerstone chemical transformation, yet traditional catalysts suffer from activity-selectivity trade-offs due to over-hydrogenation and C–X bond hydrogenolysis. Herein, we present a Co–Zn dual-atom catalyst (Co 1 Zn 1 @NC) via mild pyrolysis (700°C) of CoZn-ZIF, where Zn volatilization generates hierarchical porosity while retaining atomically dispersed Zn sites. The catalyst features an armor architecture with Co–N 4 and Zn–N 4 sites anchored on N-doped carbon encapsulating a magnetic Co nanoparticle core. In p -chloronitrobenzene hydrogenation (70°C, 1 MPa H 2 ), it delivers 99.9% conversion and 99.9% selectivity to p -chloroaniline, outperforming Co 1 @NC (42.5% conversion) and inactive Zn 1 @NC. The catalyst exhibits broad substrate tolerance and stable performance over 8 cycles with magnetic recovery. Density functional theory reveals Co–N 4 lowers H 2 activation barrier, while Zn–N 4 selectively binds nitro groups over amino groups, accounting for the exceptional performance. This Co–Zn synergy establishes a robust, magnetically recoverable platform for sustainable fine chemical synthesis. Download: Download high-res image (302KB) Download: Download full-size image