We present the results of a reactivity study of titanium cationic clusters towards CO, C₂H₂, C₂H₄ and C₃H₆ based on guided-ion-beam mass spectrometry and DFT calculations. We identified Ti₂O₄⁺ and to a lesser extent TiO₂⁺ species which preferentially undergo oxidation reactions. An oxygen centered radical of Ti₂O₄⁺ is responsible for selective oxidation. Energy profiles and MD simulations reveal the mechanisms of the reactions. Regeneration of the oxygen centered radical was achieved experimentally and theoretically through the reaction of N₂O with Ti₂O₃⁺.