Preparation and Evaluation of Iron-Based Catalysts from Corncob for NO Reduction

Abstract

ABSTRACT This paper presents a one-step method that significantly simplifies the biomass carbonization preparation with Fe0 as active catalyst. The catalyst activity was compared to that of the catalyst prepared by a two-step method using a fixed-bed reactor for NO removal. The effects of temperature on catalyst preparation and that of SO2 on catalyst activity were also studied. The active species and surface structures of the catalysts were determined using X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis-mass spectrometry (TGA-MS), and CO temperature-programmed reduction (CO-TPR), respectively. Fe0 and Fe3C were the active catalytic species during NO removal. The catalysts prepared by the one-step method had a higher NO removal ability than that of the catalyst prepared by the two-step method. This was attributed to the small particle sizes of Fe0 and Fe3C as well as their high selectivity and anti-sintering characteristics. The catalyst prepared at 800°C exhibited the highest catalytic activity because of the special morphology. Catalyst deactivation was caused by oxidation of low-valence iron to Fe3O4 by NO, which was accompanied by agglomeration and sintering. Low SO2 concentrations affected the catalyst activity during NO removal.