Aberration corrected and monochromated environmental transmission electron microscopy: challenges and prospects for materials science

The latest generation of environmental transmission electron microscopes incorporates aberration correctors and monochromators, allowing studies of chemical reactions and growth processes with improved spatial resolution and spectral sensitivity. Here, we describe the performance of such an instrument using examples taken from studies of fuel cells and supported catalysts. We discuss the challenges involved in performing in situ gas reaction experiments quantitatively and reliably and we highlight the care required to understand the effect of the electron beam on dynamic experiments performed in the electron microscope.