Recent Advances in Cerium-Based Catalysts for NO Reduction by CO: A Review

Nitrogen oxides (NOx) are a significant component of air pollutants, and research on denitrification (de-NOx) catalysts has become relatively mature. However, in specific fields, such as industrial production and vehicle operation, exhaust also primarily contains carbon monoxide (CO). CO selective catalytic reduction (CO-SCR) effectively eliminates NOx from flue gases while converting CO into non-toxic carbon dioxide (CO2). Although Ce-based catalysts are a major focus of research in de-NOx treatment, there is a lack of comprehensive reviews on their application in CO reduction of NO. This review examines the reaction mechanisms of CO-SCR and evaluates the catalytic performance of various Ce-based catalysts within the current research framework. Both catalysts with Ce-based active components and supported cerium-based catalysts showed superior performance, with NO conversion rates typically exceeding 90% and complete CO conversion at approximately 300 °C. This review examines catalyst chemical poisoning and outlines the deactivation causes of Ce-based catalysts when exposed to oxygen, water vapor, and sulfur dioxide. It also proposes corresponding mitigation strategies. On this basis, some suggestions for future research on industrial flue gas denitrification are proposed. This review seeks to offer insights for the industrial use of CO-SCR catalysts.