One-Step Amination on Porous Wood Aerogel for Direct CO2 Capture from Atmosphere

Given the substantial emissions of carbon dioxide (CO₂) into the atmosphere, currently at a level of over thirty billion metric tons annually, there is a critical need of effective CO₂ adsorbents at scale, ideally derived from abundant natural resources as sustainable materials. In this work, sustainsble wood was used to fabricate structured wood aerogel as porous support <i>via</i> solvent dissolution and regeneration process, followed by surface modification with a series of amino silane coupling agents to produce aminated wood aerogel as CO₂ adsorbent. The as-synthesized optimal adsorbent exhibited a high CO₂ sorption capacity of up to 1.5 mmol/g and 1.3 mmol/g at 0 °C and 25 °C at 1 bar, respectively. Notably, in-depth analysis showed that the adsorbent achieved an impressive capacity of CO₂ uptake of 0.65 mmol/g at 25 °C at an exceptionally low CO₂ pressure of 0.4 mbar, <i>i.e.</i>, under ambient CO₂ 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 wood aerogel as a compelling alternative for carbon capture, contributing to global initiatives combating CO₂ emissions and stressing the key role of sustainable materials in tackling this global environmental challenge.