Site-Engineered MnGa@In-CHA OXZEO Catalysts for Synergistic Methane and Nitrogen Oxides Abatement

作者：Chunlei Zhang, Guangyan Xu, Yanshuang Zhang, Yun Zhong, Qiqi Cai, Yingao Zhang, Luna Ruan, Min Xiao, Zidi Yan, Yong De Yan, Yunbo Yu, Hong He · 发表于：Environmental Science & Technology · 年份：2025 · DOI：10.1021/acs.est.5c06606 · 被引用次数：4 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Advanced Photocatalysis Techniques

The rapid growth of natural-gas vehicles (NGVs) necessitates robust catalysts for the simultaneous abatement of methane (CH 4 ), nitrogen oxides (NO x ), and carbon monoxide (CO) under fluctuating exhaust compositions. We reported a site-engineered MnGa@In-CHA OXZEO catalyst in which indium was confined within an SSZ-13 framework, and Ga 2 O 3 and Mn 2 O 3 phases were uniformly dispersed on its exterior. Mn 2 O 3 markedly enhanced redox capacity, driving NO → NO 2 oxidation and lowering the activation energy for C–H bond cleavage in CH 4, while Ga 2 O 3 tuned the Brønsted acidity and mediated electron transfer among In, Mn, and Ga centers. In situ DRIFTS studies identified CH 4 activation at InO + sites as the rate-determining step and revealed key intermediates (CH 3 NO 2 ) that bridged the NO x reduction and CH 4 /CO oxidation pathways. The optimal Mn 1 Ga 1 @In-CHA achieved ≥90% NO x conversion at 390 °C, CH 4 conversion at 495 °C, and complete CO oxidation at 300 °C under both lean and rich conditions. It also maintained high activity after 24 h in a humid feed and exhibited stable performance across a wide range of O 2 concentrations. These combined features─high activity, selectivity, stability, and adaptability─underscore the promise of MnGa@In-CHA catalysts for NGVs exhaust abatement and offer an important design strategy for multifunctional emission-control materials.