Aminated Microcrystalline Cellulose Aerogel for Efficient CO₂ Capture

Abstract Given the substantial emissions of CO 2 into the atmosphere, there is a critical need for effective CO 2 adsorbents at scale, ideally derived from abundant and sustainable natural resources. In this work, microcrystalline cellulose derived from cotton is used to fabricate cellulose aerogel as porous support via a NaOH/urea‐based dissolution and regeneration process, followed by surface modification with a series of amino silane coupling agents to produce aminated cellulose aerogel as CO 2 adsorbent. The as‐synthesized optimal adsorbent exhibits a high CO 2 sorption capacity of up to 1.5 and 1.3 mmol g −1 at 0 °C and 25 °C at 1 bar, respectively. Notably, in‐depth analysis shows that the adsorbent achieves an impressive capacity of CO 2 uptake of 0.29 mmol g −1 at 25 °C at an exceptionally low CO 2 pressure of 0.4 mbar, i.e., under ambient CO 2 pressure. It implies its potential use as adsorbent both for the traditional point‐source capture and the direct air capture as an emerging negative emission technology. This study underscores the environmentally friendly, cost‐effective, and biosourced attributes of aminated cellulose aerogel as a compelling alternative for carbon capture, contributing to global initiatives combating CO 2 emissions and stressing the key role of sustainable materials in tackling this global environmental challenge.