奥地利材料化学研究所教授G. Rupprechter团队实现了单粒子催化中多频振荡的解析与纳米级界面通讯。 相关研究成果发表在2021年5月20日出版的《科学》。

在多相催化研究中，单个粒子的单个纳米面的反应性通常是不可分辨的。

研究人员将原位场发射电子显微镜（FEM）应用于弯曲铑晶体（半径650纳米）的顶点，实现了振荡催化氢氧化的高空间分辨率（~2纳米）和时间分辨率（~2毫秒），并对单个面上的吸附物种和反应前沿进行了成像。以电离水为成像物质，用场离子显微镜（FIM）直接对活性部位进行成像。

研究人员分别监测了不同结构纳米晶面的催化行为和它们之间的耦合程度。研究人员观察到有限的界面耦合、夹带、频率锁定和重建引起的空间耦合崩溃。实验结果得到了含氧物种覆盖率和振荡频率随时间变化的微观动力学模型的支撑。

附：英文原文

Title: Resolving multifrequential oscillations and nanoscale interfacet communication in single-particle catalysis

Author: Y. Suchorski, J. Zeininger, S. Buhr, M. Raab, M. Stger-Pollach, J. Bernardi, H. Grnbeck, G. Rupprechter

Issue&Volume: 2021/05/20

Abstract: In heterogeneous catalysis research, the reactivity of the individual nanofacets of single particle is typically not resolved. We applied in situ field electron microscopy (FEM) to the apex of a curved rhodium crystal (radius of 650 nanometers), providing high spatial (~2 nanometers) and time resolution (~2 ms) of oscillatory catalytic hydrogen oxidation, imaging adsorbed species and reaction fronts on the individual facets. Using ionized water as imaging species, the active sites were directly imaged by field ion microscopy (FIM). The catalytic behavior of differently structured nanofacets and the extent of coupling between them were monitored individually. We observed limited interfacet coupling, entrainment, frequency-locking, and reconstruction-induced collapse of spatial coupling. The experimental results are backed-up by microkinetic modelling of time-dependent oxygen species coverages and oscillation frequencies.

DOI: 10.1126/science.abf8107

Source: https://science.sciencemag.org/content/early/2021/05/19/science.abf8107