Methods
Probe and image corrected FEI Titan TEM/STEM microscope; X-FEG emission gun; GIF Quantum® ERS system; Pt M4,5-edges at 2120 eV (red) and Ru L2,3-edges at 2838 eV (green); voltage: 300 kV; STEM mode; EELS low core-loss spectrum (1500 – 3500 eV) exposure time: 18 ms; EELS high core-loss spectrum (200 – 2200 eV) exposure time: 1 ms; convergence angle: 19 mrad; collection angle: 34 mrad; beam current: 260 pA; total exposure time: just over 3 min