Facile synthesis of mesoporous melamine-formaldehyde spheres for carbon dioxide capture

Abstract

Greenhouse effect and excessive carbon dioxide (CO₂) emissions have caused widespread public concern in recent years. Tremendous efforts have been made towards CO₂ capture promoting the development of numerous sorbents. In this study, mesoporous melamine-formaldehyde spheres (MMFSs) with high surface area (298 m² g⁻¹), uniform pore sizes (3.0 nm) and high nitrogen content (∼45%) have been successfully synthesized using Pluronic F127 and sodium dodecyl sulfonate (SDS) as the templates, glycol as the organic co-solvent, and melamine (M) and paraformaldehyde (PFA) as the precursors, respectively. These MMFSs are highly effective in capturing CO₂, with the maximum adsorption capacity of 48.0 mg g⁻¹ at 273 K for CO₂. Moreover, the CO₂/N₂ selectivity at 298 K reaches 24.3, which is attributed to the high N content allowing for high binding affinity with CO₂ and the well-defined mesopores (3.0 nm). This approach suggests a new direction in designing CO₂ sorbents with excellent selectivity.