In situ manipulation of the active Au-TiO2 interface with atomic precision during CO oxidation
In situ manipulation of the active Au-TiO2 interface with atomic precision during CO oxidation
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CO 氧化过程中以原子精度原位操控活性 Au-TiO2 界面
DOI：
10.1126/science.abe3558
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发表时间：
2021-01-29
期刊：
影响因子：
56.9
通讯作者：
Zhang, Ze
中科院分区：
文献类型：
--
作者：
Yuan, Wentao;Zhu, Beien;Zhang, Ze
反应过程中的旋转测定反应条件下多相催化剂的变化可以深入了解反应机理。在反应条件下，金属纳米颗粒不仅可以改变形状，而且它们与氧化物载体的相互作用也会受到影响。Yuan等人使用像差校正的环境透射电子显微镜来研究低电子束剂量下钛表面上的金纳米颗粒。在总压为几毫巴和500°C的一氧化碳（CO）氧化过程中，他们观察到金纳米颗粒旋转了约10°，但当CO被移除时，金纳米颗粒又回到了原来的位置。密度泛函理论计算表明，旋转诱导的变化，在界面处的吸附分子氧的覆盖。在一氧化碳氧化过程中，二氧化钛表面上金纳米颗粒的外延旋转改变了金属氧化物原子界面。金属催化剂与载体之间的界面在多相催化中起着关键作用。外延界面通常被认为是刚性的，并且在催化反应期间以原子精度调整其固有微结构是具有挑战性的。使用像差校正的环境透射电子显微镜，我们研究了金（Au）和二氧化钛（TiO 2）支持之间的界面。直接的原子尺度的观察表明，一氧化碳（CO）氧化过程中的金纳米粒子的TiO 2表面上的外延旋转的Au-TiO 2界面的原子结构的一个意想不到的依赖。利用Au-TiO_2的可逆可控旋转特性，通过改变气体和温度，实现了对活性Au-TiO_2界面的原位操控。这一结果表明，在操作条件下的催化界面的实时设计是可能的。
Rotation during reaction Determining changes in heterogeneous catalysts under reaction conditions can provide insight into mechanisms. Under reaction conditions, not only can metal nanoparticles change shape but their interaction with the oxide support could also be affected. Yuan et al. used aberration-corrected environmental transmission electron microscopy to study gold nanoparticles on titanium surfaces at low electron beam doses. During carbon monoxide (CO) oxidation at total pressures of a few millibars and 500°C, they observed that gold nanoparticles rotated by about 10° but returned to their original position when CO was removed. Density function theory calculations indicated that rotation was induced by changes in the coverage of adsorbed molecular oxygen at the interface. Science, this issue p. 517 Epitaxial rotation of gold nanoparticles on a titania surface during carbon monoxide oxidation altered the metal-oxide atomic interface. The interface between metal catalyst and support plays a critical role in heterogeneous catalysis. An epitaxial interface is generally considered to be rigid, and tuning its intrinsic microstructure with atomic precision during catalytic reactions is challenging. Using aberration-corrected environmental transmission electron microscopy, we studied the interface between gold (Au) and a titanium dioxide (TiO2) support. Direct atomic-scale observations showed an unexpected dependence of the atomic structure of the Au-TiO2 interface with the epitaxial rotation of gold nanoparticles on a TiO2 surface during carbon monoxide (CO) oxidation. Taking advantage of the reversible and controllable rotation, we achieved in situ manipulation of the active Au-TiO2 interface by changing gas and temperature. This result suggests that real-time design of the catalytic interface in operating conditions may be possible.