화학공학소재연구정보센터
Catalysis Letters, Vol.40, No.1-2, 35-38, 1996
Selective Catalytic Reduction of Nitrogen Monoxide with Methane over Impregnated in/HZSM-5 in the Presence of Excess Oxygen
In/HZSM-5 catalyst prepared by the impregnation method was active for NO reduction with methane. Complete reduction of NO was obtained at 450 degrees C over an In/HZSM-5 catalyst. The presence of oxygen in the feed greatly enhanced the NO reduction activity of In/HZSM-5. Co/HZSM-5 and Ga/HZSM-5 were less effective than In/HZSM-5. Cu/HZSM-5, In/Na-ZSM-5 and In2O3/Al2O3 were ineffective for NO reduction with CH4. The NO reduction activity was proportional, to the level of indium impregnated onto HZSM-5 but excess amounts of indium were detrimental to the catalytic activity. Phase analysis by XRD measurements demonstrated that there was a threshold value in the indium content, i.e., the maximum dispersion capacity of indium oxides. It is concluded that highly dispersed indium species are the active centers for the selective catalytic reduction of NO with CH4.