Ce-TiO2催化剂在含SO2气氛下的NH3-SCR中毒机理及其Co3O4改性性能

通过对Ce-TiO₂催化剂在含硫气氛下、不同温度的NH₃-SCR活性演变，结合含硫组分的定量分析、原位红外分析，研究了Ce-TiO₂催化剂在不同温度的SO₂中毒机理。结果表明，在180 ℃下，Ce-TiO₂脱硝活性对硫酸铈的生成极为敏感，0.1 mmol·g⁻¹的硫酸铈生成导致脱硝活性从50.7%降至18.5%，随后硫酸铈持续沉积，低温脱硝活性缓慢下降；在240 ℃下，Ce-TiO₂脱硝活性对硫酸铈的生成敏感性较低，脱硝活性随时间缓慢下降，0.18 mmol·g⁻¹的硫酸铈生成导致脱硝活性从100%降至53.8%，随后硫酸铈持续生成。Co改性活性结果表明：在180 ℃时，脱硝活性从50.7%提升至94.2%，且180 ℃和240 ℃抗硫性能均有所提升。进一步的表征测试表明：Co的掺杂能提升Ce-TiO₂催化剂的氧化还原性能，并抑制SO₂在催化剂表面的吸附，提升催化剂的抗硫性能。原位红外测试结果表明：硫酸化后的Ce-Co-TiO₂催化剂仍能维持了E-R、L-H脱硝反应路径的进行，保证了一定的低温脱硝活性。本研究探索了SCR催化剂的中毒机制，可为其改性与活性提升提供参考。

Study on NH3-SCR poisoning mechanism and Co3O4 modification of Ce-TiO2 catalyst in SO2 atmosphere

The SO2 poisoning mechanism of the Ce-TiO2 catalyst at different temperatures was investigated by the evolution of NH3-SCR activity under SO2-containing atmosphere, combined with the quantitative analysis of sulfur-containing components and in-situ DRIFTS analysis. The results demonstrated that the denitrification activity of Ce-TiO2 was extremely sensitive to the generation of cerium sulfate at 180 ℃, and the generation of 0.1 mmol·g−1 of cerium sulfate led to the rapid decrease of denitrification activity from 50.7% to 18.5%, followed by the continuous deposition of cerium sulfate and the slow decrease of low-temperature denitrification activity. When the reaction temperature increased to 240 ℃, the denitrification activity of Ce-TiO2 was less sensitive to the generation of cerium sulfate, and the denitrification activity slowly decreased from 100% to 53.8% with the generation of 0.18 mmol·g−1 cerium sulfate. With the doping of Co3O4, the denitrification activity was increased from 50.7% to 94.2% at 180 °C, and the sulfur resistance was improved at both 180 °C and 240 °C. Further characterization tests showed that Co doping could enhance the redox performance of the Ce-TiO2 catalyst and inhibited the adsorption of SO2 on the catalyst surface to enhance the sulfur resistance of the catalyst. The in-situ infrared spectra demonstrated that the sulfated Ce-Co-TiO2 catalyst could still maintain the E-R and L-H denitrification reaction paths and ensure a certain low-temperature denitrification activity.