Mechanistic investigation of enhanced reactivity of NH 4 HSO 4 and NO on Nb- and Sb-doped VW/Ti SCR catalysts
Mechanistic investigation of enhanced reactivity of NH 4 HSO 4 and NO on Nb- and Sb-doped VW/Ti SCR catalysts
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DOI：
10.1016/j.apcata.2017.10.011
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发表时间：
2018-01
影响因子：
5.5
通讯作者：
Dong Ye;Ruiyang Qu;Cheng-hang Zheng;K. Cen;Xiang Gao
中科院分区：
文献类型：
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作者：
Dong Ye;Ruiyang Qu;Cheng-hang Zheng;K. Cen;Xiang Gao
研究了V-SCR中添加sb2o5和nb2o5对NH4HSO4分解、NH4HSO4与NO的反应性以及抗硫性的促进作用。sb2o5和nb2o5的加入增加了SO42−中S原子周围的电子云密度，这对SO42−在低温区向so2的转变有积极的影响。结果表明，促进剂修饰的催化剂明显增强了nh4hso4的分解行为。同时，随着Sb2O5和Nb2O5的引入，nh4hso4与NO具有较高的反应活性，这可以解释为Sb2O5-和Nb2O5掺杂的催化剂表面上V5+和活性亲电氧的数量增加。最后，通过引入nb2o5和Sb2O5，在一定程度上阻碍了so2和H2O对催化剂的失活，表明这两种促进剂修饰的催化剂可能在未来的低温SCR系统中具有代表性。
This study focused on promotional effect of Sb2O5and Nb2O5addition to V-SCR on decomposition of NH4HSO4, reactivity of NH4HSO4and NO, and sulfur resistance. Adding Sb2O5and Nb2O5increased the electron cloud density around the S atoms in SO42−, which exerted a positive effect on the transformation of SO42−to SO2in the lower temperature region. As a result, the decomposition behavior of NH4HSO4was obviously enhanced on the promoters-modified catalysts. Meanwhile, a high reactivity of NH4HSO4with NO was observed with the introduction of Sb2O5and Nb2O5, which could be explained by the increased amount of V5+and reactive electrophilic oxygen species on the Sb2O5- and Nb2O5-doped catalyst surfaces. Finally, the deactivation of catalysts by SO2and H2O was impeded in a certain extent through introducing Nb2O5and Sb2O5, suggesting that these promoters-modified catalysts might be typically used in the low-temperature SCR systems in the future.