The effect of polyethylene glycol modification on CrOx/TiO2 catalysts for NO oxidation

Abstract CrOx was loaded on a different amount of polyethylene glycol modified TiO2 (CrOx/yPEG-TiO2) by impregnation method, successfully utilized in NO oxidation. The structure-property relationships of the catalysts were explored through different characterization techniques including XRD, BET, Raman, XPS, H2-TPR, O2-TPD, NO-TPD and in situ DRIFTS. The results pointed out that the polyethylene glycol modification could enhance the interaction between CrOx with TiO2. Among these CrOx/yPEG-TiO2 (y = 0, 30, 50, 80) catalysts, the CrOx/50PEG-TiO2 had the strongest interaction between CrOx with TiO2, which resulted in more chemical adsorption oxygen. Meanwhile, CrOx/50PEG-TiO2 had a certain amount of Cr6+. It exhibited the highest catalytic activity due to the synergy between CrOx and chemical adsorption oxygen, which reached 55% at the temperature of 350 °C. Moreover, the CrOx/50PEG-TiO2 still exhibited wide activity temperature windows of 225–425 °C and good stability.