In heterogeneous catalysis research, the reactivity of individual nanofacets of single particles is typically not resolved. We applied in situ field electron microscopy to the apex of a curved rhodium crystal (radius of 650 nanometers), providing high spatial (~2 nanometers) and time resolution (~2 milliseconds) of oscillatory catalytic hydrogen oxidation, to image adsorbed species and reaction fronts on the individual facets. Using ionized water as the imaging species, the active sites were directly imaged with field ion microscopy. 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 modeling of time-dependent oxygen species coverages and oscillation frequencies.

在多相催化研究中，单个粒子的单个纳米面的反应性通常无法解析。我们将原位场电子显微镜应用于弯曲的铑晶体（半径为 650 纳米）的顶点，提供振荡催化氢氧化的高空间（~2 纳米）和时间分辨率（~2 毫秒），以对吸附的物质和反应进行成像各个方面的正面。使用离子水作为成像物质，活性位点直接用场离子显微镜成像。不同结构的纳米面的催化行为和它们之间的耦合程度被单独监测。我们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。