Secondly, any small fraction of the previously present superlattice peaks that correspond to the intermetallic phase disappeared into the background. This means that while the goal of the dealloying was to form a Pt-rich overlayer, the rather strong S-activation also affected the bulk properties of the intermetallic Pt-Cu core and partly disordered the crystal structure to the point where the intermetallic phase is no longer visible under the used measurement conditions due to too small domain size . On the other hand, the exposure of the Pt-Ni electrocatalyst to the harsher S-activation (Figure ) also resulted in the successful removal of the pure Ni phase. However, in contrast to the more M rich Pt-Cu catalyst, the stronger S-activation did not significantly change the bulk composition of the Pt-Ni catalyst, resulting in only a very slight shift in the position of the most intensive XRD peaks. In addition, unlike in the case of Pt-Cu (Figure ), the presence of a small fraction of the intermetallic phase for the Pt-Ni catalyst remained unchanged even after the harsher S-activation (Figure ).