论文标题
朝向CEO的表面羟基物种$ _2 $纳米颗粒
Towards the surface hydroxyl species in CeO$_2$ nanoparticles
论文作者
论文摘要
了解功能性纳米材料的复杂化学反应至关重要。原子水平的受控合成和表征对于获得许多纳米材料所表现出的独特化学反应性的深入了解至关重要。氧化岩纳米颗粒具有许多工业和商业应用，这是由于非常强大的催化性，抗氧化活性而产生的。但是，活性物种的身份和纳米症赋予的化学机制仍然难以捉摸，这阻碍了新应用的进一步发展。在这里，我们探索了不同温度下具有不同大小的氧化元素纳米颗粒的行为，并通过最先进的软X射线实验与计算方法相结合，追踪电子结构的变化。我们证实在CEO2NANOPAPTICLE表面的CE（III）氧化态，即使对于小至2 nm的颗粒也是如此。在CE L3和M5EDGES上进行的同步X射线吸收实验，结合X射线衍射（XRD），高分辨率透射透射电子显微镜（HRTEM）和较小的角度X射线散射（SAXS），理论计算表明，除了在Nananoceria的构造中，还表明，除了这些化学效果，还可以在氢化型组合中进行盐分的化学效果。
Understanding the complex chemistry of functional nanomaterials is of fundamental importance. Controlled synthesis and characterization at the atomic level is essential to gain deeper insight into the unique chemical reactivity exhibited by many nanomaterials. Cerium oxide nanoparticles have many industrial and commercial applications,resulting from very strong catalytic, pro-and anti-oxidant activity. However, the identity of the active species and the chemical mechanisms imparted by nanoceria remain elusive, impeding the further development of new applications. Here, we explore the behavior of cerium oxide nanoparticles of different sizes at different temperatures and trace the electronic structure changes by state-of-the-art soft and hard X-ray experiments combined with computational methods. We confirm the absence of the Ce(III) oxidation state at the surface of CeO2nanoparticles, even for particles as small as 2 nm. Synchrotron X-ray absorption experiments at Ce L3and M5edges, combined with X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and small angle X-ray scattering (SAXS) and theoretical calculations demonstrate that in addition to the nanoceria charge stability, the formation of hydroxyl groups at the surface profoundly affects the chemical performance of these nanomaterials
