Abstract <p>The influence of additives of ozone (or hydrogen peroxide) and helium as an inert diluent in a stoichiometric hydrogen–air mixture on the detonation wave parameters has been studied numerically using a detailed chemical kinetic mechanism. It has been established that the mole fractions of these additives can be selected so that the detonation cell size in the resulting mixture remains close to the average cell size in the pure mixture, while the temperature of the detonation products is significantly reduced. It has been shown that the addition of hydrogen peroxide and helium reduces the stability of the detonation wave against disturbances caused by multiple obstacles (barriers) located in the channel, thus contributing to the suppression of the wave. In contrast, detonation in a mixture with ozone and helium additives at selected concentrations is found to be more stable against these disturbances than in the pure mixture.</p>