Zero-emission NO<sub>2</sub> capture using divalent metal cation-exchanged zeolites for air purification.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41253766.
- Also identified by DOI 10.1038/s41467-025-65052-z and PMC identifier 12627719.
- Licence recorded as CC BY-NC-ND.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The global adoption of hydrogen and biofuels, though central to decarbonization, risks aggravating NO<sub>2</sub> pollution as their combustion drives up NO<sub>x</sub> emissions through hotter flames and excess oxygen. Effective ambient NO<sub>2</sub> removal is critical for protecting human health, yet existing adsorbents often release toxic NO, limiting practical deployment. Here, we overcome this grand challenge by developing divalent metal cation-exchanged zeolites that achieve complete NO<sub>2</sub> capture with "zero" NO emission. Exemplified by Ca<sup>2</sup>⁺- and Mn<sup>2</sup>⁺-exchanged zeolites, these materials operate under both dry and humid (70% RH) conditions, even at NO<sub>2</sub> concentrations up to 500 ppm. Mechanistic studies reveal that divalent cations, acting as surface active sites, can suppress NO formation via stabilizing its intermediate. We further demonstrate real-world applicability by integrating these zeolites into a wearable air-purifying respirator, enabling a "zero-NO<sub>x</sub> shield" for personal protection. This work establishes NO<sub>2</sub> adsorption chemistry and offers a scalable pathway to clean air solutions.