In this study, we synthesized a Ce-modified Mn/HZSM-5 adsorbent via the ultrasound-assisted impregnation for Hg0 capture. Given the addition of 15% CeO2, ~ 100% Hg0 efficiency was reached at 200 °C, suggesting its promotional effect on Hg0 removal. The doped Ce introduced additional chemisorbed oxygen species onto the adsorbent surfaces, which facilitated the oxidation of Hg0 to HgO. Even though adding CeO2 led to a weakened adsorbent acidity, yet it appeared that this negative affect could be completely overcome by the enhanced oxidative ability, which finally endowed Ce-modified Mn/HZSM-5 with a satisfactory Hg0 removal performance within the whole investigated temperature range. During the Hg0 capture process, chemisorption was predominant with Mn4+operating as the main active site for oxidizing Hg0 to Hg2+. Finally, the 15Ce-Mn/HZSM-5 adsorbent exhibited good recyclability and stability. However, its tolerance to H2O and SO2 appeared relatively weak, suggesting that some modification should be conducted to improve its practicality.
Keywords: Capture; Cerium; Elemental mercury; HZSM-5; Manganese.
© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.