Insight into the enhancing activity and stability of Ce modified V₂O₅/AC during cyclic...

Cyclic desulfurization-regeneration-denitrification over carbon-based catalysts is a promising technology for SO₂ and NOx simultaneous elimination in steel industry. Regeneration is imperative to the long-term operation of the process, while the research is limited. In this work, Ce modified V₂O₅/AC catalyst (CeVOx/AC) with higher desulfurization and denitrification activity was prepared and the effect of cyclic regeneration was investigated. Results illustrated that the desulfurization and denitrification activity of CeVOx/AC gradually improved with increasing the regeneration cycles at the optimum regeneration temperature of 470 °C in N₂. The increasing Ce³⁺, V⁵⁺ and oxygen vacancies, enhanced surface acidity and improved redox ability contributed to the catalytic activity of regenerated catalysts. For desulfurization, more SO₂ transformed into H₂SO₄ rather than to metal sulfates after cyclic regeneration. For denitrification, the improved redox ability accelerated the oxidation of NO to active NO₂, bridged nitrites and nitrates, and the enhanced acidity facilitated the NH₃ adsorption, further generating more -NH₂ and promoting the SCR activity of regenerated samples. The CeVOx/AC with good activity and regenerative stability shows great application potential in steel industry for the simultaneous SO₂ and NOx removal.