Heterogeneous Uptake of Hydrogen Peroxide on Mineral Oxides

The interaction of mineral oxides (α-Al₂O₃, MgO, Fe₂O₃, and SiO₂) with hydrogen peroxide was investigated using the Knudsen cell reactor. The initial reactive uptake coefficients for the commercially available powders are measured as (1.00±0.11)×10^-4 for α-Al₂O₃, (1.66±0.23)×10^-4 for MgO, (9.70±1.95)×10^-5 for Fe₂O₃, and (5.22±0.9)×10^-5 for SiO₂. These metal oxide powders exhibit some catalytic behavior toward the decomposition of hydrogen peroxide excluding SiO₂. H₂O₂ can be destroyed on Fe₂O₃ surface and O₂ is formed. The experimental results suggest that the heterogeneous loss on mineral surface can represent an important sink of hydrogen peroxide.