A review of methods and strategies for NO and CO pollutant removal from flue gas using copper-based catalysts: Mechanisms and performance

With the rapid acceleration of industrialization, the emission of nitrogen oxides (NO_x) and carbon monoxide (CO) has emerged as a pressing global environmental issue, posing significant threats to ecosystems and human health. Copper-based catalysts have garnered substantial attention in the field of multi-pollutant synergistic treatment due to their abundant availability, low cost, and superior catalytic performance. This paper provides a comprehensive review of the recent advancements in copper-based catalysts for the removal of NO_x and CO from flue gas, with a focus on their applications in selective catalytic reduction (SCR), CO catalytic oxidation, and bifunctional co-catalysis. Through an in-depth analysis of key factors influencing catalytic performance—such as valence modulation, morphological structure design, optimization of preparation methods, auxiliary doping, and adjustment of metal ratios—the critical roles of various catalyst properties are elucidated. These include redox capabilities, acidic nature, surface oxygen vacancy concentration, and active site dispersion in the catalytic process. Furthermore, this paper explores in detail the reaction mechanisms and sulfur-resistant properties of copper-based catalysts employed in several strategies for NO_x and CO removal, highlighting the potential of bifunctional catalysts for simultaneous NO_x and CO abatement. Significant progress has been achieved in enhancing low-temperature activity and stability through the optimization of preparation processes, intermetallic interactions, and structural design of copper-based catalysts. These advancements provide crucial theoretical insights and practical guidance for the development of future environmental treatment technologies, paving the way for more efficient and sustainable solutions to address global pollution challenges.