Influence of preparation method on the performance of FeMnCeOx catalyst in NH3-SCR at (ultra) low temperature
SUN Jingfang1, CAI Yandi2, YU Yaxin3, AN Dongqi3,TIAN Xiaocong4, ZOU Weixin2*, DONG Lin1, 2, 3*
(1 Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Nanjing University, Nanjing 210093, Jiangsu, China;2 School of Environment, Nanjing University, Nanjing 210093, Jiangsu, China；3 Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu, China；4 National Demonstration Center for Experimental Chemistry Education, Nanjing University, Nanjing 210093, Jiangsu, China)
Abstract:
Mn-based catalysts possess excellent catalytic performance in NH3 selective catalytic reduction (NH3-SCR) at (ultra) low temperature, but the poor sulfur resistance limits their further industrial application. In this study, FeMnCeOx catalysts were modified by optimizing the ratios of active components and adjusting the preparation method. The results indicated that FeMnCeOx(S) catalyst prepared by the sol-gel method had better catalytic performance than FeMnCeOx(C) catalyst prepared by the co-precipitation method, and could obtain NO conversion rate of more than 90% between 80 ℃ and 150 ℃. At the same time, the activity of FeMnCeOx(S) catalyst can be stably maintained in the atmosphere of 0.01% (volume fraction) SO2 at 120 ℃, showing excellent sulfur resistance. Combined with the characterization results of textural properties, surface acidity, redox performance and the chemical states of surface species, it was found that the samples prepared by the sol-gel method exhibited better redox property, stronger surface acidity and more surface species conducive to low temperature SCR.Furthermore, the NH3-SCR reaction on FeMnCex(S) followed the Eley-Rideal reaction mechanism. The combined effects of the above factors produced a better deNOx performance for FeMnCeOx(S) catalyst.
KeyWords:
sol-gel method; deNOx performance; (ultra) low temperature; FeMnCeOx catalysts
