Preparation of γ‐Fe2O3 Catalysts and their deNOx Performance: Effects of Precipitation Conditions

다국어 초록 (Multilingual Abstract)

Magnetic γ‐Fe2O3 catalysts were prepared by microwave‐assisted coprecipitation utilizing the direct‐titrate and back‐titrate precipitation technique with different precipitants, namely, (NH4)2CO3, NaOH, Na2CO3, and NH4OH, which were evaluated in the selective catalytic reduction of NOx with NH3. The optimum γ‐Fe2O3 catalyst preparation method was direct titration with NH4OH as the precipitant, which exhibits high deNOx efficiency. This direct titration was effective to maintain the proper crystallization degree of γ‐Fe2O3, improve the pore structure, and suppress the formation of α‐Fe2O3 phase, being advantageous to get tiny and uniform discrete γ‐Fe2O3 particles with high activity in selective catalytic reduction. NH4+‐based precipitants in direct titration leads to an increase of the surface O/Fe atom ratio, and more lattice oxygen sites are exposed to the crystal surface.
Fe‐based catalysts are considered as efficient eco‐friendly catalysts for selective catalytic reduction. Magnetic γ‐Fe2O3 catalysts were prepared by microwave‐assisted coprecipitation using direct‐titrate and back‐titrate precipitation techniques with different precipitants. The γ‐Fe2O3 catalyst made with NH4OH as precipitant exhibited an excellent NH3‐SCR denitration performance.