Synergizing Surface Heterointerfaces with Oxygen-Rich Solid-Solution Supports: A Robust Architecture for Toluene Abatement

Abstract

Precise modulation of active sites is pivotal for optimizing catalytic volatile organic compound (VOC) elimination. Herein, we synthesized distinct ternary Mn-Co-Ce oxide catalysts via impregnation and doping strategies to systematically decouple the catalytic impacts of heterointerface versus solid-solution structures. A comparative investigation reveals that the 3MnO 2 /Co1Ce6-P catalyst, featuring a MnO 2 -Co1Ce6-P heterointerface, significantly outperforms its solid-solution counterpart (Mn3Co1Ce6-P). Structural and mechanistic analyses demonstrate that the interfacial strategy facilitates the construction of Mn 4+ -Ov-Ce 3+ interfacial structure. This asymmetric coordination environment effectively accelerates electron transfer and boosts the mobility of surface lattice oxygen. Therefore, the interface-engineered catalyst demonstrates enhanced redox cycling efficiency and optimized surface acidity for toluene adsorption, delivering exceptional lowtemperature activity (T 90 = 234 ℃), prolonged stability, and impressive water tolerance. In contrast, the solid-solution structure is constrained by valence mismatch and lattice rigidity, which inhibit the generation of active oxygen species. Density functional theory (DFT) calculations corroborate these findings, confirming that the interfacial architecture simultaneously lowers the energy barriers for both oxygen vacancy formation and toluene adsorption. This work underscores the structural advantages of constructing heterointerfaces on oxygen-rich substrates, offering a rational design paradigm for advanced rare-earth-based catalysts.