Effects of SiO2/Al2O3 ratio, reaction atmosphere and metal additive on de-NOx performance of HC-SCR over Cu-based ZSM-5

This study aims to investigate the catalytic performance of 2Cu/ZSM-5 with different SiO2/Al2O3 ratios (30, 75, and 90) for selective catalytic reduction (SCR) of NOx by C3H6. The coexistent CO and H-2 in the C3H6-SCR process were also evaluated to further improve the de-NOx performance. The SiO2/Al(2)O(3 )ratios and coexistent CO and H-2 significantly affected the de-NOx performance and its operating temperature window. The addition of 1 wt.% metal additives (Pt, Ce, Sn, and Mn) to 2Cu/ZSM-5 exhibited a distinct improvement in catalytic performance. Among the metal-additive catalysts, 2Cu1Sn/ZSM-5 demonstrated favorable NOx conversion in the H-2- or CO-C3H6-SCR process owing to the enhancement of partial oxidation of C3H6 by H-2. This resulted in improved low-temperature catalytic performance, without any accompanying side reactions that produce NH3, N2O, and HNCO. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.