Proton exchange membrane water electrolyzers are essential for the hydrogen economy, yet reducing the cost of anode catalysts remains a critical barrier to mass production. Building on our previous work, where we developed efficient low-loading Ir-Ru catalysts on enhanced proton exchange membranes via thin-film magnetron sputtering, we aim to further explore catalyst behavior. Earlier ESRF measurements revealed that in the Ir-Ru system, Ru leaches from the surface, forming an Ir-Ru@IrOx structure, with alloying also observed. This study will examine whether Ir-Ru@IrOx formation depends on the Ir-Ru ratio or microstructure, influenced by sputtering power. We will investigate the structural evolution of Ir-Ru catalysts prepared at varying powers of the magnetron sputtering.