Fast and selective CO2 capture from outdoor air by covalent organic frameworks

[Geoengineering News]

https://www.nature.com/articles/s41893-025-01735-1

Authors: Zihui Zhou, Tianqiong Ma, Heyang Zhang, Neda S. Sabeva & Omar M. Yaghi 

07 January 2026

Abstract

Capturing CO2 directly from ambient air is necessary for managing carbon levels and supporting long-term climate sustainability. However, the slow adsorption and desorption kinetics of current direct air capture sorbents remain a major limitation, whereas faster kinetics allow for quicker CO2 uptake and greater air throughput—both are essential for enhancing system efficiency. In this work, we present a covalent organic framework (COF) with both fast kinetics and high CO2 uptake. The COF (termed COF-1000) exhibited a CO2 capacity of 1.31 mmol g−1 under dry conditions at 400 ppm CO2, reaching half of its capacity within 8.1 min. Under humid conditions (75% relative humidity), water further enhanced both uptake and kinetics, leading to a remarkable CO2 capacity of 2.19 mmol g−1 with a reduced half-capacity time of 6.8 min. The exceptionally fast kinetics observed for COF-1000 were further demonstrated by using outdoor air as the CO2 source, where 50 adsorption–desorption cycles were conducted within 3 days, yielding a CO2 uptake of 22.1 mmol g−1 d−1, a value exceeding the current state-of-the-art materials. These results highlight COF-1000’s potential to enable efficient, scalable direct air capture and promote sustainable carbon mitigation.

Source: Nature Sustainability