Addition of Formaldehyde to Slowly Reacting Hydrogen + Oxygen Mixtures

Abstract

The effect of HCHO in reducing the induction periods of H2+ O2+ N2 mixtures at 500°C has been examined for a range of mixture composition, using HCHO concentrations in the range 0.05–1.0 %. Computer treatment shows that the marked reduction can only be accounted for by the reaction HO2+ HCHO = H2O2+ HCO(24). A detailed computer analysis of the results for a range of mixtures gives the ratio k24/k½10= 23 (mol l.–1 s)–½. Taking k10(HO2+ HO2= H2O2+ O2)= 1.8 × 109 gives k24= 9.6 × 105 l.mol–1 s–1. With A24= 109, this corresponds to E24= 10.7 kcal mol–1.