Fig. 2: Location and species of sulfur after SO2 aging.
From: Simple physical mixing of zeolite prevents sulfur deactivation of vanadia catalysts for NOx removal
a, b TEM image and line-EDS of the SO2 aged VWTi. c, d TEM image and line-EDS of the SO2 aged VWTi + Z. In the segregated region of the VWTi (Ti, black) and Y zeolite (Si, navy), a distribution of sulfur (orange) could be investigated. e Micropore distribution of the VWTi+Z fresh, SO2-aged and regenerated catalysts from the Ar adsorption results. To eliminate the effect of the structure degradation under SCR conditions at 220 °C, VWTi + Z treatment under a NH3-SCR reaction for 22 h (black) was suggested as a standard. f Thermal decomposition profiles of sulfur species on the SO2-aged VWTi + Z and VWTi catalysts. Decomposed sulfur species were measured by using mass spectrometry, and any other sulfur species was not detected except SO2. A low temperature peak at ~400 °C is assigned to SO2 from the decomposition of ABS, and high temperature peak at ~700 °C is SO2 from a decomposition of metal sulfate.
