O-vacancy formation in the surface layer aside the Ru nanorod (green squares in Figure ) or in deeper layers of the ZrO2 support underneath the nanorod (blue squares in Figure ) results in a very small or even negligible lowering of the O-vacancy formation energy as compared to the corresponding O-vacancy formation energy on the bare ZrO2 support, although there is still some charge transfer possible. Consequently, the related data points are above the red fit line.