Review on the impact of SO2 on VOCs oxidation: Mechanisms and anti-poisoning strategies

Emissions of volatile organic compounds (VOCs) cause serious hazards to human health and environmental quality and have become the main focus of air pollution control in many countries and around the world. Catalytic oxidation is widely used to control emissions of VOCs, and the catalysts are the core of catalytic oxidation technology. The presence of trace sulfur species in the actual waste gas inevitably causes toxicity to the catalysts. This phenomenon affects the removal efficiency of VOCs and significantly increases the operating cost, limiting the application of catalytic oxidation technology. This paper first discusses the effect of sulfur dioxide on VOCs oxidation catalysts. The detailed processes of SO2 adsorption, migration, and conversion on catalysts are summarized. The regeneration methods of sulfur poisoning catalysts are discussed, and various methods for the development of anti-sulfur poisoning catalysts, such as element doping and acidification, are summarized. Finally, the effects of some process parameters on catalyst sulfur poisoning in practical industrial applications are concluded. It provides a reference value for future anti-sulfur poisoning strategies, mechanism analysis, and practical industrial applications of VOCs oxidation catalysts.