Reactions of pure and doped rhodium cluster cations, RhX (n = 2-6; X = Al, V, Co, Rh), with NO molecules were investigated at near-thermal energy using a guided ion beam tandem mass spectrometer. We found that the doping with Al and V increases the total reaction cross section mostly. Under single-collision conditions, RhX reacts with NO to produce RhN with release of metal monoxide, XO, whereas RhX (n = 3-6) adsorb NO. For the specific clusters RhAl (n = 3 and 4) and RhV (n = 4-6), the NO adsorption is often accompanied by the release of one Rh atom. In addition, we examined the reactions of RhX (X = Al, V, Co, Rh) with NO under multiple-collision conditions and observed the cluster dioxide formation and the N release, i.e., NO decomposition. Particularly, the V-doping is most effective for the NO decomposition. One possible explanation for the present results is that the formation of a stable dopant metal-oxygen bond directly leads to the increase of NO dissociative adsorption energy and the reduction of the energy barrier between the molecular and dissociative adsorption, thereby encouraging the NO decomposition on the small RhX clusters studied.