Active site exposure of sulfur-etched CeO2 nanorods for nitrogen oxide reduction

CeO2 is an extensively used catalyst in denitration reaction, however, weak acidity of CeO2 is not conducive for NO conversion. Traditional sulfur etching by impregnation results in a large amount of sulfate deposition. To address this limitation, washing with deionized water was added following traditional impregnation (S1.0-CeO2-wash catalyst). The washing process successfully reduced the sulfate deposition, optimized the pore structure of the S1.0-CeO2-wash catalyst. The NO removal rate of the S1.0-CeO2-wash sample reached approximately 90% at 250–350 °C. Additionally, the Ce4+ content on the surface of S1.0-CeO2-wash catalyst increased. Moreover, the action of the S1.0-CeO2-wash catalyst in the reaction was determined to follow both Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms. This work provides a reference for the acid etching of other catalysts.