Deactivation mechanisms and anti-deactivation strategies of copper-based catalysts in selective catalytic reduction reactions: A review

With the increasing awareness of environmental protection, the threat of NOx to air quality and human health has attracted widespread attention. Selective catalytic reduction (SCR) technology has become the focus of research as an effective means to remove NOx. Given China's stringent environmental policies, air pollution control is advancing rapidly. To strike a balance between environmental protection and economic viability, efforts should focus on reducing catalyst costs, extending their service life, and maintaining high catalytic activity. Among the various catalyst options, Cu-based catalysts are particularly valued for their outstanding low-temperature catalytic activity, affordability, and broad operating temperature range. The research history of these catalysts dates back to the 1970s and primarily develops along two main directions: molecular sieve systems and multi-component composite systems supported by TiO2. These catalysts demonstrate remarkable advantages in low-temperature activity and wide temperature windows. However, Cu-based catalysts are often poisoned in practical applications due to the interference of various toxic substances, which leads to the decrease of catalytic performance and eventual catalyst inactivation. This paper reviews the poisoning mechanisms and anti-poisoning strategies of Cu-based catalysts for SCR reactions, focusing on the effects of toxic compounds such as SO2, H2O, alkali/alkaline earth and heavy metals, etc. on catalyst activity. To address the issue of easy poisoning in Cu-based catalysts, a strategy is proposed to enhance their anti-poisoning performance by introducing metal dopants, modifying the carrier, and optimizing the structure. Finally, this paper discusses the challenges and development prospects of Cu-based catalyst research, which is expected to become one of the core catalysts for SCR denitrification technology in the future by continuously optimizing the catalyst design.