Delaminated Fe₂O₃-Pillared clay: Its preparation, characterization, and activities for selective catalytic reduction of NO by NH₃

A delaminated Fe₂O₃-pillared clay catalyst was prepared for the selective catalytic reduction (SCR) of NO by NH₃ at above 300°C. The delaminated pillared clay was characterized by inductively coupled plasma-atomic emission spectroscopy chemical analysis, X-ray diffraction structure and line broadening analyses, micropore size probing, and Mössbauer analysis. These analyses showed that the catalyst contained fragmented Fe₂O₃-pillared clay forming “house-of-cards” structure with dispersed Fe₂O₃ particles approximately 170 Å in size. The SCR activity of the delaminated pillared clay was higher than the commercial-type V₂O₅ + WO₃/TiO₂ catalyst, and also higher than the undelaminated pillared clay and supported Fe₂O₃ catalysts, under conditions without SO₂. Infrared measurements of adsorbed NH₃ showed strong Brønsted acidity which was caused possibly by interactions between Fe₂O₃ and clay.