On Rh/TiO1.98, the oxygen vacancy facilitates CO2 dissociation and is restored by the dissociated oxygen, potentially supporting catalytic stability. In contrast, on Rh/TiO1.69, the dissociated oxygen remains at the bridging site between two Ti cus atoms, which may impact long-term surface reactivity. These trends highlight the role of surface reducibility and active site availability in influencing CO2 activation behavior, emphasizing the balance between adsorption strength and reactivity for optimizing catalytic performance.