Nanoconfinement effects of mesoporous CuMn2O4 spinel for constructing efficient Hg0 removal catalysts

Abstract

Developing high-performance mercury removal catalysts is essential for addressing atmospheric mercury pollution. Notably, conventional mineral adsorbents are ineffective for high-temperature flue gases (>300 °C). In this study, confinement catalysis was utilized to modify CuMn₂O₄. Under the chlorine-free catalytic condition, the temperature window of T₉₅ was widened by 150 °C (for 50–400 °C) toward high-temperature. Mechanistic studies suggest that nanoconfinement effects significantly improve the catalytic performance. Molecular oxygen adsorption and activation capacity were dramatically enhanced, as demonstrated by NAP-XPS. The plentiful grain boundaries effectively adjust the defect species and electronic structure of the catalysts in favor of Hg⁰ catalysis, whereas the porous structure improves the reactant adsorption properties.