Max-Planck-Institut für Metallforschung, 70569 Stuttgart, Germany.
Nano Lett. 2011 Nov 9;11(11):4697-700. doi: 10.1021/nl2023564. Epub 2011 Oct 19.
We studied the interaction of oxygen with MgO(100) supported Pd nanoparticles at 10(-5) mbar oxygen pressure and a sample temperature of 570 K. We employed high-resolution X-ray reciprocal space mapping, which allows us to resolve the average particle shape from the quantitative analysis of intensity diffraction rods running perpendicular to corresponding facet surfaces. We identified the oxygen induced formation of nanosized (112) facets which is reversible in a CO atmosphere. Our results give direct evidence for the microscopic evolution of the nanoparticle shape under reactant exposure, which is essential for an atomistic understanding of catalytic reactions on nanoparticles.
我们研究了在 10-5 毫巴氧压和 570K 样品温度下，氧气与 MgO(100)负载钯纳米颗粒的相互作用。我们采用了高分辨率 X 射线倒易空间测绘，这使我们能够从与相应面外表面垂直的强度衍射杆的定量分析中解析出平均颗粒形状。我们确定了氧诱导的纳米级 (112) 面的形成，该形成在 CO 气氛中是可逆的。我们的结果为反应物暴露下纳米颗粒形状的微观演变提供了直接证据，这对于理解纳米颗粒上的催化反应的原子水平至关重要。
