Promotional effects of copper doping on Ti-Ce-Ox for selective catalytic reduction of NO by NH3 at low temperature

A series of copper-doped Ti-Ce-Ox complex oxide catalysts were synthesized by sol-gel method and evaluated for selective catalytic reduction of NO by NH3 at low temperature. The promotional effect of copper doping on their structure, acidity and catalytic activity were investigated by means of Brumauer-Emmett-Teller (BET), temperature-programmed reduction (H2-TPR), X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature programmed desorption (NH3-TPD) and pyridine adsorption infrared spectrum (Py-IR) technologies. Results showed that the copper additives could improve the low temperature catalytic performance for selective catalytic reduction of Ti-Ce-Ox catalyst and the NO conversion efficiency of Ti-Cu-Ce-Ox catalyst reached above 90% at 150–250 °C (Ti/Cu=4). The introduction of copper could enhance the redox property of the Ti-Ce-Ox complex oxide catalyst, refine the particle size caused by lattice distortion and oxygen vacancy defect and enhance the acid amount of the Lewis acid site. Moreover, Ti-Cu-Ce-Ox complex oxide catalyst also had good anti-sulfur ability and anti-water influence, when injecting 300 ppm SO2 and 10 vol.%H2O, the NO conversion efficiency of Ti-Cu-Ce-Ox catalyst reached 80%.

Graphical AbstractH2-TPR profiles of Ti-Ce-Ox and Ti-Cu-Ce-Ox complex oxide catalysts. The introduction of copper can enhance the redox property of the Ti-Ce-Ox complex oxide catalyst and the Ti-Cu-Ce-Ox complex oxide catalyst has good redox property at low temperature (100–200 °C)Figure optionsDownload as PowerPoint slide