Wang Sha, Liu Jun, Jin Zaisheng, Guo Shiqi, Cheng Danhong, Deng Jiang, Zhang Dengsong
Innovation Institute of Carbon Neutrality, International Joint Laboratory of Catalytic Chemistry, Research Center of Nano Science and Technology, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
Environ Sci Technol. 2024 Jul 16. doi: 10.1021/acs.est.4c05260.
Renewing metal-poisoned NH-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 VO-WO/TiO catalysts employed in NH-SCR techniques. The regeneration is achieved by employing a masking and reconstruction strategy, which involves the in situ formation of NO to mediate the production of SO. This enables the effective bonding of Pb and triggers the reconstruction of active VO sites. In situ spectroscopy confirms that the sulfation of PbO restores acidity, while the occupied effect resulting from the sulfation of TiO promotes the formation of more polymeric VO 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 NH-SCR systems.
再生金属中毒的NH-SCR催化剂在减轻环境污染和同时利用危险废物方面具有巨大潜力。含有重金属的离子化合物由于其高极化率，往往表现出有限的溶解度，这使得传统的洗涤技术在去除重金属毒物方面无效。本研究提出了一种基于气体的方法，用于再生NH-SCR技术中使用的重金属中毒的VO-WO/TiO催化剂。通过采用掩蔽和重构策略实现再生，该策略涉及原位形成NO以介导SO的产生。这使得Pb能够有效键合，并触发活性VO位点的重构。原位光谱证实，PbO的硫酸化恢复了酸度，而TiO硫酸化产生的占据效应促进了更多聚合VO物种的形成。因此，与新鲜催化剂相比，再生催化剂表现出更高的活性和对金属中毒的优异抗性。这种创新方法为延长中毒催化剂的寿命、减少废物产生和提高NH-SCR系统的效率提供了一个有前景的解决方案。
