Abstract: As a green oxidant, hydrogen peroxide is predominantly produced via the anthraquinone process, which currently faces the core challenge of unsatisfactory catalytic performance using traditional palladium-based catalysts. To address this, this work focuses on the construction of the Pd₄S active phase and investigates its performance in the anthraquinone hydrogenation for hydrogen peroxide production. Using PdSO₄ as a precursor, a Pd₄S/Al₂O₃ catalyst was successfully prepared via high-temperature H2 reduction. Structural characterization (XRD, XPS, CO-IR, etc.) reveals that the introduction of S atoms alters the coordination environment of Pd atoms, resulting in more isolated active sites. Meanwhile, the electronic interaction between Pd and S significantly modulates the electron density of Pd, enhancing the adsorption and activation capacity of the carbonyl group in the anthraquinone molecule during the reaction, thereby effectively improving both activity and selectivity. In the anthraquinone hydrogenation reaction, the Pd₄S/Al₂O₃ catalyst exhibits excellent catalytic performance, achieving a hydrogenation efficiency of 16.4 g/L within 60 minutes, which represents an approximately 34% improvement compared to the conventional Pd/Al₂O₃ catalyst. This study provides a new strategy of synergistic electronic and geometric modulation for the development of high-performance anthraquinone hydrogenation catalysts.

Key words: anthraquinone hydrogenation, hydrogen peroxide, Pd4S catalyst, electronic modulation, hydrogenation efficiency