NH₃‐SCR Performance Enhancement of LDHs‐Based NiMnFe‐Mixed Oxides by Two‐Phase Coexistence and Cooperation

Abstract

Mixed oxides with NiMnFe‐LDHs as precursors were synthesized and evaluated as catalysts in selective catalytic reduction of NO with NH3 (NH3‐SCR). Appropriate calcination temperature was identified to achieve optimal catalyst. The results pronouncedly affirmed that the catalytic performances of the as‐acquired catalysts were vulnerable to calcination temperature, where Ni3Mn1Fe1‐600 presented preferable DeNOx activity with above 90% NO conversion and 98% N2 selectivity in the range of 150‐360 °C. Multiple characterizations exhibited that the outstanding DeNOx activity was determined by the coexistence as well as cooperation of NiFe2O4 spinel and Ni6MnO8 phase, which could contribute more surface active sites, and synergetic effect arising from the electron transfer between Ni, Mn ions and Ni, Fe ions. Furthermore, a more rapid redox cycle and optimal DeNOx performance were resultantly accomplished.