The Roles of Sulfur-Containing Species in the Selective Catalytic Reduction of NO with NH3 over Activated Carbon

Abstract

In the selective catalytic reduction (SCR) of NO with NH3 over activated carbon (AC), deactivation occurs over time in the presence of SO2. This work distinguishes the multiple roles of SO2 in the gas phase versus the solid deposition product and clarifies the effects of the physicochemical properties of AC on NO conversion. The deposition products were detected using temperature-programmed desorption (TPD) coupled with mass spectrum (MS) analysis and Fourier transform infrared (FTIR) spectrometry. The results showed that the activated carbon loses less de-NOx activity when it has more CO- and CO2-containing groups with decomposition temperatures over 900 K. The Raman spectra revealed that the disorder of the microcrystalline structure of the graphite has a positive linear correlation with NO conversion regardless of the presence of functional groups. The deposition products were analyzed by Gaussian-Lorentz deconvolution of the TPD spectra, and it was discovered that the sulfur-containing species include...