Absorptive reduction of NO-from off-gas has been investigated. With regard to negligibly low solubility of nitrogen monoxide in aqueous solutions, technical application of any absorption process has to be based on absorption with chemical reaction at the interphase. The present investigations have been based on the redox reaction 2 NO + 4 H+ + 4 e(-) double right arrow N-2 + 2 H2O Combining this thermodynamic principle of NO-reduction with a redox-absorption process should enable separation processes comparable with SCR-denoxing. Several processes with promising redox conditions have been investigated. The program has considered the reactivity, the nature of products and mass transfer problems. The results confirm, that NO itself does not participate,any kind of reactive absorption process. Nitrogen monoxide has to be preferably oxidized in a first step to form NO2 and has to be absorbed in a second step. Depending on the ratio of NO/NO2 (or NO/N2O4) the products may differ. Gaseous NZ has definitely been observed only, when absorbing NO2/N2O4.