Adsorption Removal of NO2 Under Low-Temperature and Low-Concentration Conditions: A Review of Adsorbents and Adsorption Mechanisms.

The efficient mitigation of harmful nitrogen oxides (NOx) under ambient conditions remains a challenging task. Selective adsorption offers a viable solution for the capture of low-concentration NOx from the polluted stream at low temperatures. This review summarizes recent progress in the development of NO2 adsorbents, delves into the understanding of adsorption mechanisms, and discusses the criteria for evaluating their performance. First, the present NO2 adsorbents are categorized according to their distinct characteristics. This review then provides insights into the mechanisms of adsorption, highlighting the interaction between active sites and NO2, drawing from both experimental and theoretical research. The performance of these adsorbents is also assessed, focusing on their capacity, reusability, stability and selectivity. Finally, perspectives are proposed to address the significant challenges and explore potential advancements for NO2 adsorbents, aiming to enhance their suitability for diverse practical application scenarios.