Scale-Bridging Solid Adsorbents for Direct Air Capture: Integrating Material Chemistry, Structured Contactors, and Advanced Regeneration Processes

As the global carbon budget rapidly depletes, the transition to a sustainable, stable climate demands the urgent, gigaton-scale deployment of negative emission technologies. Direct air capture (DAC) has emerged as an essential, emissions source independent pathway toward global net-zero targets. Compared to solvent-based systems, solid adsorbent-based DAC holds distinct advantages due to its broader material versatility, modular scalability, and streamlined equipment architecture. However, transitioning from laboratory-scale material discovery to commercial deployment requires a holistic, system-level engineering approach. Because intrinsic adsorbent properties dictate the design of scalable structured contactors, the selection of energy-efficient regeneration methods, and the ultimate techno-economic and environmental viability of the process, these interdependent components must be synergistically co-optimized. To address this co-optimization challenge, this review provides a critical, integrated evaluation of solid adsorbent DAC. By systematically analyzing recent advancements across adsorbent development, structured contactor engineering, regeneration strategies, and system-level assessments, we outline a strategic roadmap to accelerate the development of commercially viable solid adsorbent DAC technologies.