Pyridinic Nitrogen-Dominated Pt/C@NC Core–Shell Nanocatalysts for Selective Hydrogenation–Rearrangement of Nitrobenzene

Carbon-encapsulated metal nanoparticles have found widespread applications in diverse chemical transformations, such as oxidation, hydrogenation, and reforming reactions. Herein, we report a facile and efficient strategy to construct ultrafine Pt nanoparticles encapsulated in N-doped defective graphene, which exhibit core–shell architectures, via in situ pyrolysis. The Pt/C@Nd12C700 catalyst with a predominant proportion of pyridinic N (49.02%) demonstrates significantly enhanced hydrogenation activity compared to Pt/C@Nr12C700. The combination of multiple characterization techniques and density functional theory (DFT) calculations further unveils that the optimized electronic structure and high dispersion of Pt arise from synergistic electronic and geometric effects. The pyridinic N triggers charge delocalization across the Pt–C interface and prompts charge redistribution among Pt, pyridinic N, and defective C sites, which induces distinct catalytic behavior on the traditionally inert external surface. The enhanced electronic interactions reconstruct the surface microenvironment of the catalyst, thereby rendering the carbon layer surface electron-abundant. Accordingly, the optimized adsorption energy of phenylhydroxylamine and the reduced activation barrier for H2 dissociation endow the pivotal phenylhydroxylamine intermediate with high specificity, enabling a relay coupling of catalytic hydrogenation and subsequent Bamberger rearrangement for the efficient production of p-aminophenol. This study presents a method for engineering the surface catalytic behavior of nitrogen-modified graphene-like confined Pt nanomaterials.