贵金属催化剂硫中毒机制及抗性提升研究进展

Research progress on the mechanism of sulfur poisoning andresistance improvement of noble metal catalysts

实际工业废气中常含有SO_(2)杂质,在污染物催化净化过程中,SO_(2)与反应物竞争吸附于催化剂活性位点,特别是易与贵金属发生化学作用生成硫酸盐,从而削弱贵金属的电子传递能力,造成不可逆的硫中毒现象。因此,如何高效再生硫中毒催化剂或者基于原子水平设计耐硫催化剂成为环境催化领域亟待解决的关键问题。首先分析了SO_(2)在贵金属催化剂上的吸附、迁移和转化过程。其次,探讨了硫中毒催化剂的再生方法,并阐明了再生机制。随后,总结了耐硫贵金属催化剂的设计策略,包括活性相调控、载体改性和包裹结构构建等,并提出构筑抗硫催化剂的关键是强化金属-金属/载体相互作用。最后,展望了耐硫贵金属催化剂未来的研究方向,以期为工业耐硫催化剂的优化设计提供指导。

SO_(2)impurities are commonly encountered in practical industrial exhaust gases.During catalytic purification processes,SO_(2)molecules compete with reactants for active sites.Particularly,SO_(2)can undergo chemical reactions with noble metals,forming sulfate salts.This interaction weakens electron transfer capabilities,leading to severe and irreversible sulfur poisoning of catalysts.Therefore,efficiently regenerating sulfur-poisoned catalysts or designing sulfur-resistant catalysts has become a crucial challenge in the field of environmental catalysis.This paper begins by analyzing the adsorption,migration,and transformation processes of SO_(2)on noble-metal based catalysts.It then explores methods for regenerating sulfur-poisoned catalysts and elucidates the involved mechanisms.Subsequently,it summarizes strategies for designing noble-metal based catalysts with excellent sulfur-resistance,including active phase regulation,support modification,and the construction of encapsulated structures,emphasizing that the key to developing sulfur-resistant catalysts lies in enhancing metal-metal/support interactions.Finally,it discusses future research directions for noble-metal based catalysts with excellent sulfur-resistance,aiming to provide guidance for the optimized design of industrial sulfur-resistant catalysts.