Iridium oxide (IrO₂) shows a good potential for CH₄ activation at mild conditions evidenced by density functional theory (DFT) and surface science studies. In this study, IrO₂ NP (nanoparticles) of around 7 nm are found to activate CH₄ at a temperature as low as −110 °C when Raman bands of surface species at 1328 and 1581 cm⁻¹ are observed, accompanied by the partial reduction of IrO₂. DFT modeling of methane activation on IrO₂ indicates that CH₃, CH₂O_br, H₂O_br, and HO_br (O_br, bridging oxygen between two Ir) are the more abundance surface species and the calculated vibrational frequencies of these species consistently explain the observed results of in situ Raman and in situ DRIFTS. The CH₄ activation temperature on Ir NP of around 5.4 nm is found nearly 200 °C higher than that over IrO₂ NP, confirming the superior activity of IrO₂. DFT modeling demonstrates the high CH₄ reactivity over IrO₂ (2 1 1) and the even higher activity of partially reduced IrO₂. This evidences the important role of the oxidation state of Ir in determining the catalytic activity and it implies that tuning Ir oxidation state and/or designing Ir-oxide interface may facilitate the fabrication of value-added chemicals from methane over iridium-based catalysts.

氧化铱（IrO ₂）在温和条件下显示出良好的CH ₄活化潜力，这由密度泛函理论（DFT）和表面科学研究证明。在这项研究中，当在1328和1581 cm ^-1处观察到表面物种的拉曼光谱带时，发现在约-110°C的温度下，约7 nm的IrO ₂ NP（纳米粒子）会激活CH ₄。还原IrO ₂。DFT模拟甲烷在IrO ₂上的活化表明CH ₃，CH ₂ O _br，H ₂ O _br和HO _br（O _br，在两个Ir之间桥接氧是更丰富的表面物质，并且这些物质的计算振动频率一致地解释了原位拉曼和原位DRIFTS的观察结果。的CH ₄上的Ir NP活化温度纳米周围5.4的是发现了近200℃高于以上的IrO ₂ NP，确认的IrO的优良活性₂。DFT建模表明，与IrO ₂（2 1 1）相比，CH ₄具有较高的反应活性，部分还原的IrO ₂具有更高的活性。这证明了Ir的氧化态在确定催化活性中的重要作用，这意味着调整Ir的氧化态和/或设计Ir-氧化物的界面可以促进甲烷在铱基催化剂上制备增值化学品。