In/H-Beta modified by Co3O4 and its superior performance in the presence of H2O and SO2 for selective catalytic reduction of NOx with CH4

Abstract

In this paper, In-metal oxide/H-Beta catalysts were synthesized by ion exchange method and In-Co3O4/H-Beta exhibited the highest catalytic activity for the selective catalytic reduction of NOx with CH4 in presence of H2O and SO2. Thus, the synthesis conditions of In-Co3O4/H-Beta were optimized. The results showed that In-Co3O4/H-Beta exhibited excellent catalytic performance and high CH4 selectively when the synthesis was carried out by ion exchange method, the ratio of Si and Al in H-Beta was 25, the ratio of Co3O4 and H-Beta was 5:40, the concentration of ion exchange liquid was 0.033 M and calcination temperature was 500 °C. The NOx removal efficiency was about 87.6 % and N2 selectivity could reach 96.3% in the presence of H2O and SO2. Through a series of characterizations, it was concluded that In-Co3O4/H-Beta owned stable catalyst structure, abundant Brønsted acid sites and the highest ratio of InO+/In2O3 under the optimal synthesis conditions. In addition, the doped of Co3O4 could inhibit the adsorption of sulfate species on the surface of In/H-Beta catalyst, leading to the excellent H2O and SO2 resistance property.

Keywords

• CH4-SCR
• Synthesis conditions
• In-Co3O4/H-Beta
• H2O resistance
• SO2 resistance