The multi-metal oxides blended activated coke for efficient NH3-SCR at super low-temperature

Abstract

In order to solve the unsatisfactory NH3-SCR in the super low-temperature range (≤150 °C), the multi-metal oxides (CuO, MnO2 and Fe2O3) modified activated coke (AC) was prepared by using a one-step blending method. The results showed that the Cu6-Mn6-Fe1/AC exhibited a high NO conversion of 74.0% at 100 °C and performed good on N2 selectivity (97.0%). The metal oxides were successfully and uniformly dispersed on the surface and matrix of ACs. The blended metal oxide increased AC’s mesoporous structure, which was favorable to the mass transfer during SCR reaction. The amount of acidic functional groups, surface chemisorbed oxygen and lattice oxygen were greatly improved on Cu6-Mn6-Fe1/AC, and thus facilitated SCR reaction through E-R mechanism. These metals existed in a variety of valence states, and the catalytic reaction was achieved by electron transfer among these metals. Various spinels such as MnFe2O4, CuFe2O4 and CuMn2O4 were found in Cu6-Mn6-Fe1/AC, which not only enhanced SCR catalytic effect, but also was conducive to inhibiting N2O production and improving the anti-sulfur performance of SCR catalysts. While possessing high SCR catalytic effect at low temperature, the catalysts were convenient and efficient, which was promising in practical industrial application