Using operando Bragg coherent x-ray diffraction imaging, we visualised three-dimensionally a single twinned-gold nanocrystal during the CO oxidation reaction. We describe the defect dynamics process occurring under operating conditions and indicate the correlation between the nucleation of highly strained regions at the surface of the nanocrystal and its catalytic activity. Understanding the twinning deformation mechanism sheds light on the creation of active sites, and could well contribute to the understanding of the catalytic behaviour of other catalysts. With the start-up of 4th generation synchrotron sources, we anticipate that coherent hard x-ray diffraction imaging techniques will play a major role in imaging in situ chemical processes.

使用操作布拉格相干 X 射线衍射成像，我们在 CO 氧化反应过程中以三维方式可视化单个孪晶金纳米晶体。我们描述了在操作条件下发生的缺陷动力学过程，并指出了纳米晶体表面高应变区域的成核与其催化活性之间的相关性。了解孪生变形机制有助于了解活性位点的产生，并有助于了解其他催化剂的催化行为。随着第四代同步加速器源的启动，我们预计相干硬 X 射线衍射成像技术将在原位化学过程成像中发挥重要作用。