Dual-atom Rh-Co catalysts for synergistically boosting nitrile hydrogenation.

Abstract

Single-atom catalysts have found widespread application in selective hydrogenation reactions partially due to their well-defined active site structures, which ensure exceptional chemical selectivity. However, the limited binding sites on single-atom catalysts hinder their application in hydrogenating larger multidentate substrates (e.g., benzonitrile). In this work, we introduced a heteronuclear Rh-Co dual-atom catalyst stabilized on the defective graphene supports (Rh₁Co₁/ND@G), which resolves the activity-selectivity trade-off in nitrile hydrogenation reaction. The Rh₁ site primarily activates H₂, whereas the Co₁ site synergistically optimizes the adsorption of benzonitrile. The cooperative interaction between Rh-Co dual sites enhances the activation of the C ≡ N bond, significantly reducing the apparent activation energy compared to Rh SACs. The Rh₁Co₁/ND@G catalyst achieves exceptional performance under mild reaction conditions, delivering a TOF of 4068 h^-1 with >98% dibenzylamine selectivity, surpassing all previous reported heterogeneous catalysts. Remarkably, the Rh₁Co₁/ND@G catalyst still maintains robust catalytic performance even after 12 cycles. This work not only presents a breakthrough in dual-atom catalyst design for nitrile hydrogenation, but also opens an avenue for developing high-performance industrial hydrogenation catalysts.