Abstract：
Renewing metal-poisoned NH3-SCR catalysts holds great potential for mitigating environmental pollution and utilizing hazardous wastes simultaneously. Ionic compounds containing heavy metals often exhibit limited solubility due to their high polarizability, making traditional washing techniques ineffective in removing heavy metal poisons. This study presents a gas-based method for regenerating heavy-metal-poisoned V2O5-WO3/TiO2 catalysts employed in NH3-SCR techniques. The regeneration is achieved by employing a masking and reconstruction strategy, which involves the in situ formation of NO2 to mediate the production of SO3. This enables the effective bonding of Pb and triggers the reconstruction of active VOx sites. In situ spectroscopy confirms that the sulfation of PbO restores acidity, while the occupied effect resulting from the sulfation of TiO2 promotes the formation of more polymeric VOx species. Consequently, the regenerated catalyst exhibits enhanced activity and superior resistance to metal poisons compared with the fresh catalyst. The innovative method offers a promising solution for extending the lifespan of poisoned catalysts, reducing waste generation, and enhancing the efficiency of NH3-SCR systems.
摘要：
更新金属中毒的NH3-SCR催化剂具有减轻环境污染和同时利用危险废物的巨大潜力。含有重金属的离子化合物通常由于其高极化性而表现出有限的溶解度，使传统的洗涤技术在去除重金属毒物方面无效。这项研究提出了一种基于气体的方法，用于再生NH3-SCR技术中使用的重金属中毒的V2O5-WO3/TiO2催化剂。再生是通过采用掩蔽和重建策略来实现的，这涉及原位形成NO2以介导SO3的产生。这实现了Pb的有效键合并触发了活性VOx位点的重建。原位光谱学证实，PbO的硫酸化恢复了酸度，而由TiO2的硫酸化产生的占据效应促进了更多的聚合物VOx物种的形成。因此,与新鲜催化剂相比，再生催化剂表现出增强的活性和对金属毒物的优异抗性。创新的方法为延长中毒催化剂的寿命提供了一个有前途的解决方案，减少废物产生，提高NH3-SCR系统的效率。
