Kawasaki Tadahiro, Ueda Kouta, Ichihashi Mikio, Tanji Takayoshi
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
Rev Sci Instrum. 2009 Nov;80(11):113701. doi: 10.1063/1.3250862.
We have developed an improved, windowed type environmental-cell (E-cell) transmission electron microscope (TEM) for in situ observation of gas-solid interactions, such as catalytic reactions at atmospheric pressure. Our E-cell TEM includes a compact E-cell specimen holder with mechanical stability, resulting in smoother introduction of the desired gases compared with previous E-cell TEMs. In addition, the gas control unit was simplified by omitting the pressure control function of the TEM pre-evacuation chamber. This simplification was due to the successful development of remarkably tough thin carbon films as the window material. These films, with a thickness of <10 nm, were found to withstand pressure differences >2 atm. Appropriate arrangement of the specimen position inside the E-cell provided quantitatively analyzable TEM images, with no disturbances caused by the windowed films. As an application, we used this E-cell TEM to observe the dynamic shape change in a catalytic gold nanoparticle supported on TiO(2) during the oxidation of CO gas.
我们开发了一种经过改进的窗口式环境舱（E-cell）透射电子显微镜（TEM），用于原位观察气固相互作用，例如大气压下的催化反应。我们的E-cell TEM包括一个具有机械稳定性的紧凑型E-cell样品架，与以前的E-cell TEM相比，能更顺畅地引入所需气体。此外，通过省去TEM预抽气室的压力控制功能，简化了气体控制单元。这种简化得益于成功开发出了非常坚韧的薄碳膜作为窗口材料。这些厚度小于10 nm的薄膜被发现能够承受超过2个大气压的压差。E-cell内部样品位置的合理布置提供了可定量分析的TEM图像，且不会受到窗口薄膜的干扰。作为应用，我们使用这种E-cell TEM观察了负载在TiO(2)上的催化金纳米颗粒在CO气体氧化过程中的动态形状变化。
