(a) HAADF-STEM image of the PdCu 1 : 1 nanoparticle mixture after ramp annealing at 750°C on the SiO2/Si substrate in a forming gas atmosphere. Scale bar is 50 nm. (b) EDX spectrum obtained for green point in (a). (c) EDX spectrum obtained for red point in (a). Table: Pd and Cu wt. % compositions measured from the spectra in (b) and (c).