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-based and MnO x -based sorbents modified with Ce and La using sol-gel method, were employed for elemental mercury removal at 120–240   °C. The Hg 0 removal activity of Mn 2 O 3 /ZSM-5 can be significantly enhanced by doping 50   at.% Ce or 10   at.% La, the Hg 0 removal efficiency increased by 94% and 71%, respectively. The Hg 0 removal ability of CuO/ZSM-5 subtly improved by addition of 50   at.% Ce or 10   at.% La, the Hg 0 removal efficiency ascended only by 6% and 18%, respectively. The XPS results revealed that Hg 0 transformed to HgO, and CuO (or Mn 2 O 3 ) was reduced to Cu 2 O (or Mn 3 O 4 ), which is in agreement with Mars-Maessen mechanism.