<p>The catalytic activation of CO₂ is a key challenge for sustainable greenhouse gas utilization. In this study, density functional theory (DFT) calculations were used to investigate CO₂ activation on Zr-based clusters doped with Ti and Cu. Compared to pristine Zr₆, doping significantly alters the electronic structure and enhances interaction with CO₂. The results show that dopant type and concentration strongly influence adsorption strength, activation barriers, and charge transfer. Increased dopant content generally improves catalytic performance by facilitating CO₂ activation, which correlates with changes in the HOMO–LUMO gap and enhanced electron transfer to CO₂. Notably, Ti- and Cu-doped clusters exhibit promising catalytic potential. In particular, Cu₂Zr₄ and Ti₃Zr₃ are identified as effective candidates for CO₂ conversion to methane. Overall, this study provides theoretical insights into the role of transition metal doping in tuning Zr-based clusters and offers guidance for designing efficient catalysts for CO₂ utilization.</p> Graphical abstract <p></p>