Title : Current research progress in heavy metals poisoning of Selective Catalytic Reduction (SCR) denitration catalysts
Abstract:
Selective catalytic reduction (SCR) technology is the most extensively used and efficient method for NOx removal owing to its high removal efficiency and environmentally friendly process. However, heavy metals that are present in flue gas can deactivate the SCR catalysts through poisoning their active sites, leading to performance deterioration. To address this challenge and reduce the operating costs of SCR systems, it is essential to investigate the mechanisms of heavy metal poisoning and develop effective strategies to mitigate its impact. We reviewed the current research progress of the poisoning mechanism of different heavy metals on SCR catalysts (including vanadium-based catalysts, manganese-based catalysts, cerium-based catalysts). Various anti-heavy metal poisoning measures and mechanisms (e.g., doping metal and non-metal elements, etc.) were summarized. Research indicates that heavy metal deposition on SCR catalysts leads to pore blockage, reducing the catalyst's specific surface area and pore volume. This will damage to the active sites on the catalyst surface, which results in the physical and/or chemical poisoning of catalyst, thereby reducing the catalyst performance. Strategies to enhance the anti-poisoning capabilities of SCR catalysts include doping with metals or non-metals and the development of advanced carrier materials. Besides, the regeneration measures of SCR catalysts poisoned by heavy metals were also reviewed. Thermal reduction method, solution wet washing and composite method are the common methods for the regeneration of heavy metal-poisoning SCR catalysts. In the end, the main conclusions and research suggestions for the development of heavy metal poisoning of selective catalytic reduction (SCR) denitration catalyst were also commented.
