LaMnO₃‑Pt Whisker-Structured Cordierite Monoliths for Low-Temperature Soot Oxidation

Diesel particulate filters (DPFs) require catalysts with both high activity and durability to achieve efficient low-temperature soot oxidation under practical exhaust conditions. In this work, a hierarchically structured LaMnO₃-Pt monolithic catalyst was constructed by growing aluminum borate whiskers on a cordierite substrate via a vapor-phase method to form a biomimetic tufted layer, followed by coating with LaMnO₃ perovskite and subsequent Pt loading. The whisker-induced structure significantly improves catalyst dispersion and soot-catalyst contact efficiency, while the synergistic interaction between LaMnO₃ and Pt effectively regulates surface oxygen species and their migration behavior. Temperature-programmed oxidation (TPO) tests demonstrate that the optimized C-LaMnO₃-Pt_0.9 wt % monolithic catalyst exhibits outstanding soot oxidation performance, with half-conversion temperature (T₅₀) reduced to 453 °C (under loose contact) and 403 °C (under tight contact), respectively, which are significantly lower than those of bare cordierite (T₅₀ = 610 °C). In addition, the catalyst maintains a CO₂ selectivity exceeding 99% during soot oxidation and shows no obvious activity degradation during repeated TPO cycles, indicating excellent thermal and structural stability. This hierarchical structural design provides a viable strategy for developing efficient and durable monolithic catalysts for soot oxidation in DPF applications.