Over the past decade, amine-loaded solid adsorbents for capturing CO2 from power plants have been widely studied. Various nitrogen (N) sources have been used for this purpose, and the current range of adsorbents, referred to here as N-functionalized solid adsorbent (NFSAs), are the subject of this review. The main synthesis methods of NFSAs are described and recent progress in the field discussed. Criteria for improving NFSA performance are highlighted with reference to a variety of solid supports, providing guidance on the selection of highly efficient, inexpensive adsorbents. A thorough assessment of adsorption mechanisms and factors influencing the adsorption process is given. The review concludes by exploring future research and development opportunities, as well as pathways for commercializing NFSAs.