Sulfur Poisoning and Regeneration of NOx Storage−Reduction Cu/K2Ti2O5 Catalyst
Sulfur Poisoning and Regeneration of NOx Storage−Reduction Cu/K2Ti2O5 Catalyst
复制标题
DOI：
10.1021/ie1009525
复制
发表时间：
2010-07
影响因子：
4.2
通讯作者：
Qiang Wang;Jiahua Zhu;Suying Wei;J. Chung;Zhanhu Guo
中科院分区：
文献类型：
--
作者：
Qiang Wang;Jiahua Zhu;Suying Wei;J. Chung;Zhanhu Guo
最近开发了一种新的Cu/K2 Ti 2 O 5催化剂，用于通过NOx储存-还原（NSR）过程去除NOx。然而，其在硫存在下的NSR性能尚未被研究。本文首次报道了Cu/K_2Ti_2O_5型NOx储存还原催化剂的硫中毒及其失活机理。研究了硫浓度、吸附/再生循环试验和程序升温再生的影响。在低温下，当SO2浓度低于20 ppm时，中毒效应可以忽略不计，并且硫酸化样品可以在550 °C下用3.5%H2容易地再生。然而，在高温下，硫物种被吸附在K +位点上以形成K2 SO 4，并因此诱导从K2 Ti 2 O 5到K2 Ti6 O 13纳米颗粒的结构转变。结构变化是可逆的，硫酸化催化剂可在650-700 ℃下用氢气再生。
A new Cu/K2Ti2O5 catalyst has been developed recently to remove NOx through the NOx storage-reduction (NSR) process. However, its NSR performance in the presence of sulfur has not been investigated. In this article, the sulfur poisoning of the NOx storage-reduction catalyst Cu/K2Ti2O5 and the corresponding deactivation mechanisms are reported for the first time. The effect of the sulfur concentration, adsorption/ regeneration cycling tests, and temperature-programmed regeneration are studied. At low temperatures, the poisoning effect is negligible when the SO2 concentration is lower than 20 ppm, and the sulfated samples can be easily regenerated by 3.5% H2 at 550 °C. However, at high temperatures, the sulfur species are adsorbed on K + sites to form K2SO4 and, consequently, induce a structure transformation from K2Ti2O5 to K2Ti6O13 nanoparticles. The structural change is reversible, and the sulfated catalyst can be regenerated by hydrogen at 650-700 °C.