Synergy of Pd ₁ –Co ₁ Dual-Atom Catalyst Breaking the Activity-Selectivity Trade-Off for Chemoselective Hydrogenation

Breaking the fundamental activity-selectivity trade-off in nitroarene hydrogenation is crucial for efficient amine synthesis yet remains a great challenge. Although single-atom catalysts offer a promising avenue, their intrinsically monofunctional nature prevents them from reconciling rapid H2 activation with selective nitro-group reduction. Herein, we pioneer a molten salt delayed-release strategy to precisely customize a dual-atom catalyst featuring heteronuclear Pd1–Co1 pairs on hierarchical microporous N-doped carbon nanosheets (Pd1Co1/NC). Experimental and theoretical studies reveal strong Pd–Co electronic coupling that modulates the d-band centers, enabling a cooperative dual-atom mechanism. Pd sites drive heterolytic H2 dissociation, while the Co sites selectively adsorb nitroarenes, spatially decoupling substrate adsorption/activation to eliminate competitive binding. This synergy simultaneously lowers the energy barrier of the rate-determining step and suppresses undesired overhydrogenation or dehalogenation. Consequently, Pd1Co1/NC displays higher catalytic activity and chemoselectivity (>99% conversion and >99% selectivity toward p-chloroaniline) than the single-atom catalysts Pd1/NC (0% selectivity at >99% conversion) and Co1/NC (>99% selectivity at 26% conversion) for the hydrogenation of p-chloronitrobenzene to p-chloroaniline. The catalyst further maintains high chemoselectivity across 29 diverse substrates containing sensitive functional groups, coupled with robust recyclability. This work establishes dual-atom catalysis as an effective strategy to resolve the persistent activity-selectivity trade-off in hydrogenation reactions for advanced chemical synthesis.