Promotional role of Co on Cu-SAPO-34 towards enhanced denitration performance and SO2 tolerance

It is well known that Cu-SAPO-34 catalyst has high activity for nitrogen oxides (NOx) abatement from diesel vehicle emission. However, its low sulfur resistance and hydrothermal stability still retard its reality application. Herein, a series of novel binary CuCo-SAPO-34 catalysts were designed and prepared through a simple one-pot method and applied for NOx selective catalytic reduction with ammonia. Compared with Cu-SAPO-34, the binary CuCo-SAPO-34 catalysts exhibited enhanced activity and SO2 tolerance. To investigate the effects of Co addition and the reaction mechanism, various characterizations including X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) mapping, physical and chemical adsorption, the in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTs), etc., were adopted. The results reveal that the Co3O4 nanoclusters existing in CuCo-SAPO-34 could efficiently accelerate the oxidation of NO to NO2, and the addition of Co is conducive to improving its sulfur resistance. In addition, CuCo-SAPO-34 also displayed superior high- and low-temperature hydrothermal stability. The binary CuCo-SAPO-34 developed in this work may be a good candidate for Cu-SAPO-34 based catalysts in practical diesel vehicle emission control.