Shock tube/laser absorption measurement of the rate constant of the reaction: H2O2 + CO2 2OH + CO2

We address the role of the linear mixing rule in the kinetics of the H2O2 decomposition system by reporting the rate constant for H2O2 + M = 2OH + M (M = Ar and CO2) in the temperature range of 1087–1234 K at low pressures in a mixture of 20% CO2 in Argon. The reaction rate constant was inferred from H2O concentrations monitored by using a laser-absorption spectroscopy-based water diagnostic. To the best of our knowledge, this is the first measurement of the rate constant of this reaction in a mixture to be reported in literature. A significant discrepancy was found between the rate constants derived using the traditional linear mixing rule and the reduced pressure linear mixing rule. This discrepancy can have serious implications on the predictive accuracy of these kinetic models, especially under conditions relevant to the operation of supercritical CO2 (sCO2) power cycles that rely on oxy-fuel combustion in a working fluid comprised almost entirely of CO2.