This approach, which is based on ideas outlined in our previous work, but differs in details, is described and illustrated in the schematics in Figure . In short, ∆𝐸 𝑅𝑢-𝑠𝑢𝑝𝑝𝑜𝑟𝑡 𝑖𝑛𝑡 can be calculated as the difference in interaction energy in the relaxed Ru/ZrO2 model catalyst and in the relaxed Ru/ZrO2-x model catalyst, with the (additional) O-vacancy, where the interaction energy is calculated as the energy difference between the complete system and the separate components, while maintaining their structure. ∆𝐸 𝑅𝑢 𝑑𝑒𝑓𝑜𝑟𝑚 corresponds to the energy required for changing the structure of the separate Ru nanorod from that in the relaxed Ru/ZrO2 to that in the relaxed Ru/ZrO2-x system, after creation of an O-vacancy in the support. Accordingly,