For the description of the Ru/ZrO2 catalyst we modified the Ru/ZrO2(111) model described in our previous work by removing the bottom three layers of the support to reduce the computational cost. This adjustment resulted in changes of the O-vacancy formation energy and in the CO adsorption energy of below 0.10 eV. Thus, the overall trends in these properties derived in our previous work remained unaffected, while specific number may change slightly.