Sulfur Poisoning in Catalytic Reactions of Gaseous Pollutants: Mechanistic Insights and Sulfur-Tolerant Catalyst Design

Sulfur poisoning remains a critical challenge for catalytic systems in gaseous pollutant abatement, as the strong chemisorptive affinity of SO₂ and its derivatives toward active sites, along with the formation of thermodynamically stable sulfates, severely disrupts redox processes and leads to irreversible deactivation. This review provides a comprehensive overview of sulfur deactivation mechanisms in catalytic reactions of VOCs, CO, and NO_x, highlighting competitive adsorption, formation of metal sulfides or sulfates, and poisoning effect of intermediate products. Mechanistic insights and recent advances in sulfur-tolerant catalyst design are systematically summarized. Three key strategies are highlighted: (i) interface engineering and defect design, which tailor electronic structure, charge transfer, and oxygen vacancy density to regulate sulfur-metal interactions; (ii) active component modulation, including bimetallic coupling and rare-earth incorporation, which stabilize redox cycles and suppress irreversible sulfate accumulation; and (iii) structural optimization of catalyst supports, involving high-surface-area porous architectures, protective core-shell or layered configurations, and finely tuned surface acid-base properties to enhance both sulfur resistance and reactant accessibility. The insights summarized herein are expected to guide the rational design of next-generation sulfur-tolerant catalytic systems, enabling sustained performance under realistic sulfur-containing conditions.