Methane conversion has received renewed interest due to the rapid growth in production of shale gas. Methane combustion for power generation and transportation is one of the alternatives for methane utilization. However, complete conversion of methane is critical to minimize negative environmental effects from unburned methane, whose noxious effect is 25 times greater than that of CO₂. Although perovskite catalysts have high thermal stability, their low activities for methane combustion prevent them from being utilized on a commercial basis. In this work, we show the impact from reconstruction of surface and subsurface monolayers of perovskite catalysts on methane combustion, using SrTiO₃ (STO) as a model perovskite. Several STO samples obtained through different synthetic methods and subjected to different postsynthetic treatments were tested for methane combustion. Through top surface characterization, kinetic experiments (including isotope labeling experiments) and density functional theory calculations, it is shown that both surface segregation of Sr and creation of step surfaces of STO can impact the rate of methane combustion over an order of magnitude. This work highlights the role of surface reconstruction in tuning perovskite catalysts for methane activation.

中文翻译：

---

了解钙钛矿催化剂表面重构对CH ₄活化和燃烧的影响

由于页岩气产量的快速增长，甲烷转化受到了新的关注。用于发电和运输的甲烷燃烧是甲烷利用的替代方法之一。但是，甲烷的完全转化对于最大程度地减少未燃烧甲烷的负面环境影响至关重要，因为未燃烧甲烷的有害作用是CO _2的25倍。尽管钙钛矿催化剂具有高的热稳定性，但是它们对甲烷燃烧的低活性阻碍了它们在商业上的利用。在这项工作中，我们显示了使用SrTiO ₃重建钙钛矿催化剂表面和亚表面单层对甲烷燃烧的影响。（STO）作为钙钛矿的典范。测试了通过不同合成方法获得的，经过不同后合成处理的几个STO样品的甲烷燃烧。通过顶面表征，动力学实验（包括同位素标记实验）和密度泛函理论计算，结果表明，Sr的表面偏析和STO的台阶面的产生都可以在一个数量级上影响甲烷的燃烧速率。这项工作强调了表面重建在调整钙钛矿催化剂活化甲烷中的作用。