This study examines the chemical reactivity of niobium clusters with carbon dioxide (CO2), with an emphasis on the analysis of the ensuing products Nb4O6+ and Nb3O6-, which show up in the cationic and anionic mass spectra, respectively. Using density functional theory (DFT) calculations, we demonstrate the reactivity of the Nbn± clusters with CO2 and reveal distinct stabilization mechanisms for the two prominent products. The stability of Nb3O6- is determined by the existence of ten π bonds pertaining to π-electron delocalization, which conforms to the nxcπ electron configuration model. Despite having only a one-atom distinction, Nb4O6+ exhibits superatomic electron shells embodying superatom stability. The divergent stabilizing mechanisms found in Nb4O6+ and Nb3O6- illustrate the intricate nature of cluster chemistry and the significance of electronic structure in governing cluster stability and reactivity.