Catalytic oxidation of gas-phase elemental mercury by nano-Fe2O3

Heterogeneous oxidation of gas-phase Hg0 by nano-Fe2O3 was investigated on a fixed bed reactor, and the e ects of oxygenconcentration, bed temperature, water vapour concentration and particle size have been discussed. The results showed that Hg0 couldbe oxidized by active oxygen atom on the surface of nano-Fe2O3 as well as lattice oxygen in nano-Fe2O3. Among the factors thata ect Hg0 oxidation by nano-Fe2O3, bed temperature plays an important role. More than 40% of total mercury was oxidized at 300°C,however, the test temperature at 400°C could cause sintering of nano-catalyst, which led to a lower e ciency of Hg0 oxidation. Theincrease of oxygen concentration could promote mercury oxidation and led to higher Hg0 oxidation e ciency. No obvious mercuryoxidation was detected in the pure N2 atmosphere, which indicates that oxygen is required in the gas stream for mercury oxidation. Thepresence of water vapour showed di erent e ects on mercury oxidation depending on its concentration. The lower content of watervapour could promote mercury oxidation, while the higher content of water vapour inhibits mercury oxidation.