The effect of dispersant characteristics on the De-NOx efficiency of SCR catalyst

In this study, we analyzed the effect of dispersant characteristics on the selective catalytic reduction (SCR) catalyst properties and de-NOx efficiency. For this, we measured the zeta potential and pH value of each dispersant, and compared the thermal properties of the dispersant through TG-DTA analysis. Also, the Py-GC/MS analysis results and the MSDS contents of the product were used to compare the components and molecular weight types of the dispersant. As a result, the higher the zeta potential, pH, and molecular weight of the dispersant, the more improved the dispersibility of the TiO₂ slurry. Characteristics such as the rheology, sedimentation, and pH change, were studied to compare the dispersibility of the catalyst slurries, and the dispersion characteristics of the TiO₂ slurries were confirmed by TEM. The SCR catalysts prepared varied based on the dispersant added, with the varying factor being the de-NOx efficiency between (250 to 450) °C depending on the dispersibility. The dispersant with the excellent dispersibility gave the highest efficiency of 84% or more at 250°C and 300°C, and the highest de-NOx efficiency of more than 92% at 350°C and 400°C.