Catalysis Today, Vol.355, 450-457, 2020
Fundamental investigation on layered double hydroxides derived mixed metal oxides for selective catalytic reduction of NOx by H-2
Selective catalytic reduction of nitrogen oxides (NOx) to N-2 by H-2 (H-2-SCR) does not create any secondary contaminants and can reduce NOx at relatively low temperature. To achieve this goal, an appropriate catalyst is essential. In this contribution, the performance of binary layered double hydroxides (LDHs) derived mixed metal oxides as support for Pt-based H-2-SCR catalysts was investigated for the first time. New H-2-SCR catalysts Pt/M3Al1Ox (M = Co, Mg, Ni, or Cu) were carefully characterized and systematically evaluated in the presence of O-2 at 120-300 degrees C. All 0.1 Pt/M3Al1Ox catalysts exhibited high SCR activity, with a NOx conversion higher than 90% at 200-220 degrees C. Among them, 0.1 Pt/Mg3Al1Ox showed higher NOx conversion rate than other catalysts, while 0.1 Pt/Ni3Al1Ox showed higher N-2 selectivity. The influences of GHSV, H-2 and O-2 feed concentration, CO2, and water vapor on the NOx conversion over 0.1 Pt/Ni3Al1Ox catalyst were also investigated. We believe that this work could provide a new option for the selection of supporting materials for H-2-SCR.