Carbon dioxide (CO2) capture using solid adsorbents at intermediate temperatures has been recognized as a promising technology, enjoying a high level of utilization in integrated gasification combined cycles (IGCC)-related processes. Solid adsorbents have attracted interest as they can capture CO2 at higher temperatures and can be disposed of with minimal environmental precautions. Among the various solid adsorbents studied, layered double hydroxides (LDHs) and magnesium oxides (MgO) have been found to be particularly suitable for CO2 adsorption in the temperature range of 200−400 °C. In recent years, significant advances have been achieved with MgO-based CO2 adsorbents, most notably through the introduction of molten salts. Therefore, we consider it essential to present a timely update on MgO materials for CO2 capture applications. In this chapter, we summarize the great progress made in this short period as well as some important results that have been published in the literature. Finally, the technology in action for current applications and a forecast for future research are briefly discussed.