Nanometer-scale resolution in an ultra-high pressure environmental TEM holder

Abstract Environmental Transmission Electron Microscopy gas holders are vital for studying catalyst nanostructures in reactive gases. Although there are existing methods to understand the behavior of catalysts during reaction, a “pressure gap” exists. Pressures of up to 4.5 bar have been demonstrated, but many industrial catalysts operate at 10–100 bar. This work introduces an ultra-high-pressure TEM gas holder designed to bridge this gap. Experiments demonstrate it can safely operate and achieve nanometer-scale resolution (~ 1.5 nm) in an Environmental TEM at pressures up to 27.5 bar. Practical resolution limitations are attributed to contamination and vibration rather than increased gas scatter. Graphical abstract