The urgent environmental concern of methane abatement, attributed to its high global warming potential, necessitates the development of methane oxidation catalysts (MOC) with enhanced low-temperature activity and durability. Herein, an iridium-doped PdOx nanoparticle supported on silicalite-1 zeolite (PdIr/S-1) catalyst was synthesized and applied for methane catalytic combustion. Comprehensive characterizations confirmed the atomically dispersed nature of iridium on the surface of PdOx nanoparticles, creating an Ir_4f–O–Pd_cus microstructure. The atomically doped Ir transferred more electrons to adjacent oxygen atoms, modifying the electronic structure of PdOx and thus enhancing the redox ability of the PdIr/S-1 catalysts. This electronic modulation facilitated methane adsorption on the Pd site of Ir_4f–O–Pd_cus, reducing the energy barrier for C–H bond cleavage and thereby increasing the reaction rate for methane oxidation. Consequently, the optimized PdIr_0.1/S-1 showed outstanding low-temperature activity for methane combustion (T₅₀ = 276 °C) after aging and maintained long-term stability over 100 h under simulated exhaust conditions. Remarkably, the novel PdIr_0.1/S-1 catalyst demonstrated significantly enhanced activity even after undergoing harsh hydrothermal aging at 750 °C for 16 h, significantly outperforming the conventional Pd/Al₂O₃ catalyst. This work provides valuable insights for designing efficient and durable MOC catalysts, addressing the critical issue of methane abatement.

中文翻译：

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制造原子铱掺杂 PdOx 纳米颗粒以实现高效、持久的甲烷减排


由于甲烷减排具有较高的全球变暖潜力，因此迫切需要开发具有增强低温活性和耐用性的甲烷氧化催化剂（MOC）。在此，合成了一种负载于silicalite-1沸石（PdIr/S-1）催化剂上的铱掺杂PdOx纳米颗粒，并将其应用于甲烷催化燃烧。综合表征证实了铱在 PdOx 纳米颗粒表面的原子分散性质，形成了 Ir _4f –O–Pd _cus 微结构。原子掺杂的Ir将更多的电子转移到相邻的氧原子，改变了PdOx的电子结构，从而增强了PdIr/S-1催化剂的氧化还原能力。这种电子调节促进了甲烷在 Ir _4f –O–Pd _cus Pd 位点上的吸附，降低了 C-H 键断裂的能垒，从而提高了甲烷氧化的反应速率。因此，优化后的PdIr _0.1 /S-1在老化后表现出出色的甲烷燃烧低温活性（T ₅₀ = 276 °C），并保持超过100 h的长期稳定性在模拟排气条件下。值得注意的是，新型 PdIr _0.1 /S-1 催化剂即使在 750 °C 的严酷水热老化 16 h 后也表现出显着增强的活性，显着优于传统的 Pd/Al ₂ O ₃ 催化剂。这项工作为设计高效耐用的 MOC 催化剂、解决甲烷减排的关键问题提供了宝贵的见解。