Amine‐Functionalized Activated Carbon Monoliths by 3D Printing for Direct Air Capture

ABSTRACT Direct air capture (DAC) is an emerging technology that supports mitigating climate change. However, its large‐scale deployment is hindered by high energy demands and material costs. In this study, we present a novel porous sorbent material for DAC using 3D‐printed activated carbon monoliths functionalized with an aminosilane compound. The monoliths were fabricated via direct ink writing and subsequently modified with 3‐aminopropyltriethoxysilane (APTES) to introduce chemisorption sites for CO 2 . Structural and chemical analyses confirmed successful grafting of amines without compromising the monolithic architecture. The resulting monoliths demonstrated enhanced CO 2 uptake at atmospheric concentrations (0.25 mmol g −1 at 0.04 kPa). IR spectroscopy revealed that the functionalized monoliths chemisorb CO 2 from ambient air as ammonium carbamate. Chemisorbed CO 2 can be desorbed at a temperature of 75°C, indicating a low energy requirement for a DAC process. To the best of our knowledge, this paper is the first published application of aminosilane‐functionalized activated carbon for DAC, highlighting its potential as a cost‐effective and scalable sorbent material.