Solid CO2 sorbents for medium- and high-temperature carbon capture: material design, shaping, and deployment for hydrogen-related processes

Abstract Due to their high-temperature resistance and potential for process intensification, medium- and high-temperature solid CO 2 adsorbents offer significant advantages in combining carbon capture with thermochemical fuel conversion and hydrogen production. Although significant progress has been made in terms of formulation, microstructure, cyclic stability and reaction mechanisms, practical evaluation must go beyond laboratory-scale CO 2 adsorption tests to encompass, in addition, formability, wear resistance, regeneration strength, reactor compatibility and application potential. This review provides a deployment-oriented synthesis of representative medium- and high-temperature solid CO 2 sorbents, including hydrotalcite-based materials, MgO-based sorbents, CaO-based sorbents, alkali metal silicates, and titanate-based systems. Particular emphasis is placed on the interrelationships between material design, adsorption properties, structural strategies, mechanical strength and suitability for hydrogen-related thermochemical processes. We also discuss intrinsic sorbent properties, affecting their applicability in fixed-bed, moving-bed, and fluidized systems, and compare different sorbent families from the perspectives of regeneration characteristics, reactor operability, and technology readiness. Finally, the major challenges and future research directions are summarized, with emphasis on standardized evaluation, scale-up-oriented shaping, reactor-relevant testing, and deployment-informed sorbent selection. By bridging the gap between fundamental materials science and large-scale industrial applications, this study aims to establish a practical framework to guide the translation of laboratory research findings into scalable and directly applicable adsorbent technologies.