Abstract: Aiming at the issues in the catalytic hydrogenation of nitrobenzene (NB) to produce p-aminophenol (PAP), such as low yield and selectivity, severe equipment corrosion, environmental pollution, and unclear technological optimization directions, this work systematically reviews the catalytic reaction mechanism, principles of regulating catalyst activity, strategies for optimizing catalyst performance, the mechanism of Bamberger rearrangement, and the influence of the medium environment on the reaction process. Analysis reveals that Pt-based catalysts exhibit excellent catalytic activity for NB hydrogenation, but the selectivity for the product PAP depends on the adsorption strength of the intermediate phenylhydroxylamine (PHA) and the reaction medium environment. The essence of catalyst modification lies in regulating the electronic structure of the metal centers to weaken their adsorption of PHA and suppress the over-hydrogenation side reaction. High selectivity for PAP can be achieved through catalyst modification methods such as doping heteroatoms, constructing core-shell structures, and forming bimetallic alloys. The properties of the support significantly affect catalyst performance, while the type of solvent and system acidity have important impacts on both hydrogenation and rearrangement reactions. Replacing sulfuric acid solutions with environmentally friendly media (CO₂/H₂O systems and solid acids) can prevent the generation of sulfate byproducts at the source, offering significant green advantages. Future research should focus on the holistic optimization of the medium-catalyst system, deepen the understanding of the reaction-transport coupling mechanism, and promote the practical application of green processes.

Key words: p-aminophenol, hydrogenation catalyst, selectivity, Bamberger rearrangement, acidic medium