Atomic Resolution Chemical Mapping of Platinum-Cobalt Nanoparticles Using Scanning Transmission Electron Microscopy-Electron Energy Loss Spectroscopy

Scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) is a powerful quantitative technique for catalyst characterisation that allows composition to be studied at high spatial resolution. Collection of EELS signal on charge-coupled device (CCD) detectors has limited the technique’s utility at higher energy losses due to high readout noise masking the low signal. New direct electron detectors (DEDs) for EELS remove the problem of readout noise and allow for reliable signals to be detected for more elements. We show data collected on platinum-cobalt nanoparticles with a direct electron EELS detector which allows for atomic resolution chemical mapping of platinum and cobalt.