Porous sorbents for direct capture of carbon dioxide from ambient air

Large-scale deployment of carbon dioxide (CO2) removal technology is an essential step to cope with global warming and achieve carbon neutrality. Direct air capture (DAC) has recently received increasing attention given the high flexibility to remove CO2 from discrete sources. Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization. This review article has summarized the recent development of porous sorbents for DAC, with a focus of pore engineering strategy and adsorption mechanism. Physisorbents such as zeolites, porous carbons, metal-organic frameworks (MOFs), and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed. At last, future directions have been proposed, and it is expected to inspire collaborations from chemistry, environment, material science and engineering communities. Technologies for removing CO2 from ambient air, known as “direct air capture” (DAC), have recently been shown to promote “negative carbon emissions”. Recent advances in surface chemistry and material synthesis have produced a new generation of CO2 adsorbents, which may promote the future and large-scale deployment of DACs. This paper introduces the main types of adsorbents for capturing CO2 from ambient air, and divides them into physical adsorption and chemical adsorption according to the adsorption mechanism. [Display omitted]