Simultaneous removal of PM and NOx over highly efficient 3DOM W/Ce0.8Zr0.2O2 catalysts

Abstract

Herein, three-dimensional ordered macropore (3DOM) x% W/Ce_0.8Zr_0.2O₂ (x = 0.5, 0.8, 1, 3) catalysts were prepared and employed for the simultaneous removal of PM (particulate matter) and NO_x from diesel engine exhaust. The contact between the solid PM and the catalyst active site was strengthened by the special 3DOM structure. 3DOM 0.8% W/Ce_0.8Zr_0.2O₂ had superior catalytic activity with a maximum concentration of CO₂ at 408 °C and nearly 100% NO conversion at 378–492 °C, and also presented high catalytic activity even under a high space velocity of 50 000 h⁻¹. Furthermore, the stability of the catalyst was excellent even after aging at 900 °C for 5 h. The large amount of chemisorbed oxygen species, good low temperature reduction performance as well as abundant acid sites enhanced the catalytic efficiency for simultaneous PM and NO_x abatement over the 3DOM 0.8% W/Ce_0.8Zr_0.2O₂ material; this is a promising catalyst for application in exhaust purification.