Optimizing amine-based adsorbents for direct air capture: A comprehensive review of performance under diverse climatic conditions

Since the Industrial Revolution, the rapid rise in greenhouse gas emissions has driven a concerning increase in atmospheric CO₂ levels, resulting in global warming and climate-related crises. In response, direct air capture (DAC) technology has emerged as a crucial negative-emissions solution, uniquely positioned to directly remove CO₂ from the atmosphere, beyond merely targeting industrial emissions. This review provides a comprehensive analysis of solid amine-based adsorbents for DAC, focusing on both performance optimization and economic viability—two essential factors for successful commercialization. A systematic classification of solid amine-based adsorbents is presented based on sorbent classes, amine types, and support materials including metal-organic frameworks (MOFs), silica, alumina, and covalent organic frameworks (COFs). Special emphasis is given to the performance of these adsorbents under varying environmental conditions, exploring humidity levels in the range of 0–100 % relative humidity and temperatures from −20 to 40 °C. By examining these factors, the review establishes regional optimization strategies to enhance the practical deployment of DAC technology worldwide. The insights provide key recommendations for optimizing DAC deployment in diverse climatic contexts and identify priority areas for further research and development to drive the technology forward.