Research progress on SCR catalysts for the synergistic removal of NO and VOCs from coal-fired power plants flue gas: A review

Abstract

NO_x and VOCs emissions from coal-fired power plants account for roughly 30% of anthropogenic emissions and provide a severe challenge to air quality protection. Synergistic NO and VOCs removal from coal-fired power plants flue gas in the SCR zone can efficiently cut treatment costs, which needs scientific investigation and is of environmental benefits. This review describes the latest research development of SCR catalysts for the synergistic removal of NO and VOCs from coal-fired power plant flue gas. Currently, the studies are mainly associated with impregnation method, co-precipitation method, hydrothermal method, sol-gel method, template method and other ways to prepare multifunctional catalysts. Doping with transition metals/ nobel metals or selecting appropriate carriers will dramatically increase the amounts of acidic sites and reactive oxygen species on the surface, resulting in a rapid rise in synergistic removal capacity. However, multiple pollutants in the actual flue gas will interact on the catalyst surface. The interaction mechanism of multiple reactants and the effect of reaction conditions on the synergistic removal rate have also been focused on. To address the problems and challenges of current research, two powerful tools, in situ technology and DFT, can be applied to explore the synergistic catalytic reaction pathways and deactivation mechanisms, guiding the design of SCR catalysts with good redox activity, low by-products, high resistance to toxicity and regeneration. Current research on synergistic NO and VOCs elimination is mainly conducted in the laboratory. In the future, the theory of multi-pollutant synergistic control should be improved to realize the practical engineering applicationsfor the synergistic removal of NO_x and VOCs from complex flue gases.

Keywords

• nitrogen oxides
• volatile organic compounds
• synergistic removal
• scr catalysts