Sulfur modification endows Co@NC catalyst exceptionally sulfur-tolerance for nitroarene hydrogenation

The catalytic hydrogenation of nitroaromatic sulfonic acids (NSAs) to synthesize aminoaromatic sulfonic acids (ASAs) is an environmentally promising alternative. However, the deactivation of current catalysts hinders its practical application. In this work, we proposed a strategy of trace sulfur modification to enhance the sulfur-tolerance of the Co@NC catalyst. Characterization revealed that Co@NC-S synthesized with cobalt sulfate has the largest particle size and specific surface area. Using sodium m -nitrobenzenesulfonate (SNS) hydrogenation as a probe reaction, the Co@NC-S catalyst demonstrated superior performance, achieving 99.52% conversion and 98.02% selectivity (100 °C, 3 MPa). Density functional theory (DFT) calculations elucidated that the remarkable sulfur-tolerance of the Co@NC-S catalyst originated from the interaction between the trace sulfur species and the cobalt nanoparticles, thereby weakening the bonding strength of Co with various sulfur-containing compounds. The Co@NC-S catalyst also exhibited excellent stability, magnetic recyclability, and versatility in hydrogenating diverse NSAs, underscoring its significant industrial potential.