Researchers have developed a composite catalyst that maintains high efficiency in removing nitrogen oxides from flue gas, even in the presence of significant potassium contamination. The study, published in the Journal of Materials Science, focuses on the selective catalytic reduction of NOx with NH3. The CeO2-Fe2(SO4)3 composite catalyst demonstrates high resistance to K poisoning.
The CeO2-Fe2(SO4)3 catalyst retained more than 90% NOx conversion across a temperature range of 300 to 400 degrees Celsius, even after the addition of 1 wt% potassium. Furthermore, at a higher potassium loading of 4 wt%, the catalyst still achieved approximately 88% NOx removal at 350 degrees Celsius.
In stark contrast, the conventional V2O5-WO3/TiO2 catalyst was completely deactivated as the K loading reached 2 wt% or higher.
Characterization of the conventional V2O5-WO3/TiO2 catalyst revealed that potassium deposition led to a reduction in specific surface area, pore volume, surface acidity, and oxidative ability. The surface acidity decreased by 41.2% due to the potassium interaction. These physical and chemical changes collectively contributed to the severe deactivation observed in the standard catalyst.
Conversely, the introduction of potassium into the CeO2-Fe2(SO4)3 catalyst triggered different textural modifications. Instead of degrading the material, the potassium led to an expanded specific surface area and the development of a more porous architecture. These changes improved the accessibility of active sites and facilitated the mass transfer of reactants within the catalyst structure.
Mechanistically, the study found that potassium ions disrupted the coordination bonds between cerium and iron cations and sulfate anions. This disruption concomitantly liberated the cerium and iron species back to their oxide states. The resulting structural rearrangement led to an enhancement in the catalyst’s intrinsic oxidation capability, which promoted reactant activation. Although there was a moderate decline in surface acidity, the retained acid sites were sufficient to sustain adequate ammonia adsorption. This synergistic interplay between structural robustness and chemical resilience underpins the exceptional alkali resistance of the CeO2-Fe2(SO4)3 catalyst.
The findings provide fundamental insights into the design of durable selective catalytic reduction catalysts for K-rich flue gas environments.
Subject of Research: Development of potassium-resistant CeO2-Fe2(SO4)3 composite catalysts for selective catalytic reduction of NOx
Article Title: CeO2-Fe2(SO4)3 composite catalysts for the selective catalytic reduction of NOx with NH3: high resistance to K poisoning
Article References: Liu, J., Ye, D., Fan, S., Wang, X., Zhu, K., & Guo, R. (2026). CeO2-Fe2(SO4)3 composite catalysts for the selective catalytic reduction of NOx with NH3: high resistance to K poisoning. Journal of Materials Science. https://doi.org/10.1007/s10853-026-14018-7
Image Credits: AI Generated
DOI: 10.1007/s10853-026-14018-7
Keywords: catalysis, NOx reduction, potassium poisoning, composite materials, emission control, cerium oxide, iron sulfate, flue gas, chemical engineering, environmental science, CeO2-Fe2, composite
News Source: Denise Maddox. (November 10, 2026). New Catalyst Resists Potassium Poisoning in NOx Reduction. Scienmag.
