Promotion of NO oxidation through H2O2 thermal decomposition using a metal surface

Considerably slow H2O2 evaporation leads to a decrease in the oxidation ratio of NO through H2O2 thermal decomposition. Therefore, the metal surfaces of Copper h62, Aluminium 5052, Steel 201, and Steel q235 were used to promote H2O2 thermal decomposition and NO oxidation. The effects of reaction temperature, H2O2 solution concentrations, H2O2:NO ratios, and metal surface inclination angles on NO oxidation were explored through H2O2 thermal decomposition. The evaporation and decomposition rates of H2O2 significantly influenced NO oxidation. After the addition of metal surfaces to the reactor, the NO oxidation ratio considerably enhanced, and NO concentration fluctuations disappeared under most conditions. The hydrophilicity of the metal surfaces can help the H2O2 solution spread rapidly on metal surfaces. The liquid film thickness decreased, which led to an increase in the H2O2 evaporation rate. Consequently, NO oxidation ratios improved. Metal surfaces promoted H2O2 decomposition to produce OH, and relatively more NO was oxidised. The highest NO oxidation ratio was 87 %, which was acquired using the 15 % H2O2 solution at 500 ℃. When temperature was higher than 300 ℃, NO oxidation ratios on different metal surfaces were similar. The inclination angle θ of metal surfaces can considerably affect NO oxidation ratios. When the metal surface was horizontal, the NO oxidation ratio was higher than that when metal surface was placed at other angles, and the oxidation effect of NO was relatively more stable. The longer the droplets stayed on metal surfaces, the smaller were the NO concentration fluctuations.