Effects of tin doping level on structure, acidity and catalytic performance of Ti-Ce-Ox catalyst for selective catalytic reduction of NO by ammonia

• Ti-Sn-Ce-Ox catalyst exhibited excellent activity for NH3-SCR.
• Tin-doped extended the active temperature window especially toward lower temperature.
• The introduction of tin inhibited grain growth and caused lattice distortion.
• The addition of tin enhanced the redox property and acidity of catalyst.
• Ti-Sn-Ce-Ox catalyst possesses good anti-poisoning ability for SO2 and water.

A series of tin-doped Ti-Ce-Ox complex oxide catalysts were synthesized by sol–gel method and tested for selective catalytic reduction of NOx with NH3 (NH3-SCR). Effects of tin additives on structure, acidity and catalytic performance of Ti-Ce-Ox for NH3-SCR of NO were investigated through characterization of N2 adsorption–desorption, H2-TPR, XRD, NH3-TPD and SEM. Results showed that tin additives extended the active temperature window especially toward lower temperatures and the NO conversion efficiency of Ti-Sn-Ce-Ox (the Ti/Sn is equal to 4) catalyst reached 92% at 200 °C. The addition of tin not only inhibit grain growth of CeO2 and TiO2, but also expand unit cell and cause lattice distortion, which are especially beneficial to NH3-SCR. Moreover the introduction of tin also improved redox property significantly and enhance the acidity of catalyst. The anti-sulfur and anti-influence of water performance of catalyst also improved by tin-doped, when injecting 300 ppm SO2 and 10 vol.% H2O, the NO conversion efficiency of Ti-Sn-Ce-Ox catalyst was still reached 85% at 200 °C.

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