This article presents a Co phase segregation strategy for creating stable Co cluster catalytic sites on TiO₂, enabling selective CO₂ hydrogenation to CO. Through oxidative calcination, pre-synthesized Co-doped brookite TiO₂ nanorods transform into a mixed TiO₂ phase, leading to the phase segregation of Co species. The resulting Co clusters, stabilized by strong Co-TiO₂ interactions during reductive CO₂ hydrogenation, effectively suppress the formation of larger nanoparticles. The undercoordinated sites of these clusters promote a high CO production rate with near-unit selectivity, contrasting with Co nanoparticles, which favor CH₄ formation under identical conditions. In-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis indicates that the weakened CO adsorption on Co clusters is key to their enhanced CO selectivity, highlighting this method as a promising approach for efficient CO₂ utilization.