The synergistic effects between Ce and Cu in Cu _{: Y} Ce _{1- y} W ₅ O _x catalysts for enhanced NH ₃ -SCR of NO _x and SO ₂ tolerance

Manganese-based metal oxides are promising catalysts for the NH ₃ -SCR (selective catalytic reduction) of NO _x at low temperatures. However, manganese-based catalysts usually exhibit poor SO ₂ and H ₂ O tolerance. In order to overcome the fatal shortcoming, non-manganese-based Cu _y Ce _1-y W ₅ O _x catalysts (y = 0, 0.4, 0.5, 0.6, 1.0) are synthesized successfully by a standard co-precipitation method, and the catalytic performances of these catalysts are tested by the NH ₃ -SCR of NO _x . The results show that there are synergistic effects between Cu and Ce, which affect the Cu _y Ce _1-y W ₅ O _x catalysts in many aspects, such as the specific surface area, the surface contents of Ce ³⁺ and Cu ²⁺ , the reductive strength and the amount of weak and strong acid sites on the surface. Moreover, the synergistic effects also have an impact on the de-NO _x mechanism of Cu _y Ce _1-y W ₅ O _x catalysts, and finally decide their catalytic performances. Among all the Cu _y Ce _1-y W ₅ O _x catalysts, the Cu _0.5 Ce _0.5 W ₅ O _x catalyst shows the best catalytic de-NO _x performance and good tolerance to SO ₂ and H ₂ O poisoning. This work may provide a suggestion for the design of non-manganese-based SCR catalysts with the desired de-NO _x performance and good SO ₂ tolerance by making use of the synergistic effects between different metal oxides.