Nonthermal Plasma Catalysis: A New Pathway for NOx Reduction

Nonthermal plasma (NTP) combined with selective catalytic reduction (SCR) is an innovative approach for flue gas treatment. This technology leverages the synergistic effects of NTP and SCR to produce plasma at low temperatures. The high-energy electrons, ions, and free radicals generated in this process interact with nitrogen oxides (NOx), effectively reducing their emissions. This study delves into the research progress of NTP-SCR technology, including the fundamental principles of plasma, catalyst improvements, reaction mechanisms, and numerical simulation studies, as well as the application potential and challenges of this technology in air purification. NTP-SCR efficiently reduces NOx at low temperatures, with minimal formation of harmful by-products and low energy consumption. NTP enhances catalyst performance, particularly enhancing activity and durability in low-temperature and harsh flue gas conditions. Mechanistic studies indicated that NTP can activate the catalyst surface and promote the reduction process of NOx. Meanwhile, the application of numerical simulation provides theoretical guidance for the design and operation of plasma reactors. Although NTP-SCR technology has significant potential, it still faces some challenges, including long-term stability, control of product selectivity, coking, and other issues in industrial applications. Future research focuses on developing more efficient and stable NTP synergistic catalysts, optimizing process parameters, and further exploring the synergistic mechanisms between plasma and catalysts.