Unveiling the synergistic effect of acidic and redox dual-active sites in LaMnO3/ZSM-5 catalyst for cracking-oxidation degradation of 1-Chloro-3-Phenylpropane

Catalytic oxidation is a promising technology for the deep cracking of chlorinated organic compounds (COCs) in pharmaceutical waste salts. The critical challenge lies in the development of catalysts that can synergistically activate C Cl bonds and promote highly efficient oxidation. Herein, this study employed a B-site doping strategy to develop a series of perovskite-type catalysts that successfully achieved the synergy of acidic and redox sites. Among them, the LaMn 0.8 Cr 0.2 O 3 /ZSM-5(25) catalyst exhibited the optimal performance in the catalytic cracking-oxidation of the model pollutant 1-chloro-3-phenylpropane. It achieved a T 90 of 260 °C, representing a significant reduction of 48 °C compared to the undoped catalyst. Moreover, it retained around 90% conversion over 60 h. In-depth mechanism study indicated that the pronounced electron transfer between Cr and Mn ions (3Cr 2+ +3Mn 4+  → 2Cr 3+ +Cr 6+ +3Mn 2+ ) not only increased the oxygen vacancy concentration but also significantly enhanced the activity of both chemisorbed oxygen (0.37 mmol·g cat −1 ) and lattice oxygen (0.23 mmol·g cat −1 ). Concurrently, the metal doping effectively exposed the inherent Si-OH-Al acidic sites in the ZSM-5 framework without altering their intrinsic nature. This synergistic mechanism drives the efficient cracking-oxidation of COCs by accelerating the steps of C Cl bond cleavage and deep oxidation of intermediates, rather than altering the reaction pathway. This work provides a solid theoretical basis and profound insights for designing multi-site synergistic catalysts for the purification of COCs.