Effect of Ce and La on the activity of CuO/ZSM-5 and MnOx/ZSM-5 composites for elemental mercury removal at low temperature

•CuO/ZSM-5 and MnOx/ZSM-5 composites were modified with Ce and La using citric acid method.•The effects of temperature, CeO2 content, and La2O3 content on mercury removal performance were examined.•The mechanism of Hg0 adsorption on CuO-based and MnOx-based sorbents at N2 atmosphere was discussed.

CuO-based and MnOx-based sorbents modified with Ce and La using sol-gel method, were employed for elemental mercury removal at 120-240 °C. The Hg0 removal activity of Mn2O3/ZSM-5 can be significantly enhanced by doping 50 at.% Ce or 10 at.% La, the Hg0 removal efficiency increased by 94% and 71%, respectively. The Hg0 removal ability of CuO/ZSM-5 subtly improved by addition of 50 at.% Ce or 10 at.% La, the Hg0 removal efficiency ascended only by 6% and 18%, respectively. The XPS results revealed that Hg0 transformed to HgO, and CuO (or Mn2O3) was reduced to Cu2O (or Mn3O4), which is in agreement with Mars-Maessen mechanism.

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