Theoretical Study of the Catalytic Activity and Anti-SO(2) Poisoning of a MoO(3)/V(2)O(5) Selective Catalytic Reduction Catalyst

[Image: see text] In this paper, density functional theory has been applied to study the mechanism of anti-SO(2) poisoning and selective catalytic reduction (SCR) reaction on a MoO(3)/V(2)O(5) surface. According to the calculation results, the SO(2) molecule can be converted into SO(3) on V(2)O(5)(010) and further transformed into NH(4)HSO(4), which poisons V(2)O(5). If V(2)O(5) and MoO(3) are combined with each other, charge separation of V(2)O(5) and MoO(3), which are negatively and positively charged, respectively, occurs at the interface. In ammonium bisulfate liquid droplets on the MoO(3)/V(2)O(5) surface, NH(4)(+) tends to adhere to the V(2)O(5)(010) surface and can be removed through the SCR reaction and HSO(4)(–) tends to adhere to the MoO(3)(100) surface and can be resolved into SO(3) and H(2)O, which can be released into the gas phase. Thus, MoO(3)/V(2)O(5) materials are resistant to SO(2) poisoning. In the MoO(3)/V(2)O(5) material, Brønsted acid sites are easily formed on the negatively charged V(2)O(5)(010) surface; this reduces the energy barrier of the NH(3) dissociation step in the NH(3)-SCR process and further improves the catalytic activity.