Cerium-optimized high-entropy spinel oxide for efficient and anti-interference removal of VOC from complex flue gas

Abstract

Efficient catalytic decomposition of volatile organic compounds (VOCs) in complex coal combustion flue gas remains a significant challenge. In this study, we synthesized a spinel-type high-entropy oxide (HEO) catalyst, (CeMnFeCoCr)₃O₄, to control the representative VOC o-xylene in the simulated complex coal-fired flue gas. Compared with the conventional multi-phase metal oxide (MMO) catalyst, (CeMnFeCoCr)₃O₄ demonstrated approximately 20% higher activity, resistance to toxic components (SO₂ and H₂O), and efficient multi-pollutant removal through reduced competitive effects. The advantages of (CeMnFeCoCr)₃O₄ arose from its unique composition and the synergistic effects within its high-entropy structure: the integration of Ce oxides—typically found in fluorite structures—into the spinel-type HEO promotes oxygen vacancy formation and promotes deep oxidation of o-xylene. The homogeneous distribution of elements contributes to its resistance against poisoning components. The high-entropy configuration promotes charge redistribution among Ce, Mn, Fe, Co, and Cr, activating inert elements (Co and Cr) to generate more active sites, enabling stable co-adsorption and efficient catalysis of multiple pollutants. This work proved the effectiveness and stability of (CeMnFeCoCr)₃O₄ in purifying complex coal-fired flue gas, potentially expanding the application of high-entropy materials in industrial settings.