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

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.

KEYWORDS:

• One-step method
• corncob
• iron nanoparticles
• Fe₃C
• NO reduction

Additional information

Funding

This work was supported by the Key Project of Liaoning provincial educational department (2019LNZD02), the Project of Liaoning provincial educational department (2019LNJC10), the National natural science foundation of China (U1910215), the 2019 Special Scientific Research Plan at Shanxi Provincial Department of Education (No. 19JK1008) and Liaoning Provincial Engineering Research Centre for Advanced Coking and Coal Utilization and The University of Science and Technology Liaoning.