Ce-TiO_(2)催化剂在含SO_(2)气氛下的NH_(3)-SCR中毒机理及其Co_(3)O_(4)改性性能  

Study on NH_(3)-SCR poisoning mechanism and Co_(3)O_(4) modification of Ce-TiO_(2) catalyst in SO_(2) atmosphere

作　　者：喜静波 陈涛 窦磊 XI Jingbo;CHEN Tao;DOU Lei(Beijing Taiyanggong Gas-fired Thermal Power Co.,Ltd,Beijing 100028,China)

机构地区：[1]北京太阳宫燃气热电有限公司,北京100028

出　　处：《环境工程学报》2023年第4期1283-1293,共11页Chinese Journal of Environmental Engineering

基　　金：北京太阳宫燃气热电有限公司企业项目资助(20H282,22H094)。

摘　　要：通过对Ce-TiO_(2)催化剂在含硫气氛下、不同温度的NH_(3)-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-TiO_(2)催化剂在不同温度的SO_(2)中毒机理。结果表明,在180℃下,Ce-TiO_(2)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-TiO_(2)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-TiO_(2)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-TiO_(2)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。The SO_(2) poisoning mechanism of the Ce-TiO_(2) catalyst at different temperatures was investigated by the evolution of NH_(3)-SCR activity under SO_(2)-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-TiO_(2) 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-TiO_(2) 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 Co_(3)O_(4),the denitrification activity was increased from 50.7%to 94.2% at 180℃,and the sulfur resistance was improved at both 180℃ and 240℃.Further characterization tests showed that Co doping could enhance the redox performance of the Ce-TiO_(2) catalyst and inhibited the adsorption of SO_(2) on the catalyst surface to enhance the sulfur resistance of the catalyst.The in-situ infrared spectra demonstrated that the sulfated Ce-Co-TiO_(2) catalyst could still maintain the E-R and L-H denitrification reaction paths and ensure a certain low-temperature denitrification activity.

关 键 词：氨气选择性催化还原(NH_(3)-SCR) 脱硝 催化剂 硫酸铈 

分 类 号：TQ426.94[化学工程]