Recent Advances of Gaseous Pollutant Catalytic Oxidation over Precious Metal Catalysts with SO2 Exposure.

Abstract

Precious metal catalysts are widely used for catalytic oxidation of various gaseous pollutants (CO, methane, and VOCs) due to their excellent catalytic activity. However, they are easily affected by SO₂ and deactivated in actual industrial waste gas or motor vehicle exhaust. Therefore, this review systematically summarizes the representative studies of gaseous pollutant catalytic oxidation over precious metal catalysts with SO₂ exposure. First, the sulfur influence mechanisms, including sulfur poisoning and sulfur promotion, as well as the influence of reaction conditions, were discussed to analyze the interaction between SO₂ and catalysts and its impact on catalyst properties. Based on the sulfur poisoning process, we further summarized the design strategies of sulfur-resistant catalysts: suppressing the adsorption of SO₂ and promoting its desorption, inhibiting the formation of sulfates and facilitating their decomposition, and constructing sacrificial sites, which can be achieved by corresponding design methods: constructing a core-shell/confined structure, dopant modification, and adjusting structural and textural properties. Furthermore, we analyzed feasible catalyst regeneration methods, including N₂/O₂ atmosphere regeneration, reducing atmosphere-assisted regeneration, and washing regeneration. Finally, the challenges and prospects of the research were proposed, hoping to provide new perspectives on understanding sulfur poisoning processes and guide the design and regeneration of sulfur-resistant catalysts.