Mesoporous Carbon Beads Impregnated with Transition Metal Chlorides for Regenerative Removal of Ammonia in the Atmosphere.

Mesoporous carbons have been widely investigated, but their real-world applications are still unfulfilled because of lacking cost-effective material synthesis and application-specific structure and shapes. Herein, we designed an efficient adsorbent based upon mesoporous carbon beads (MCBs) for regenerative removal of NH3 in the atmosphere. By employing a suspension strategy, millimeter-sized MCBs are prepared which not only have well developed porous structure but also value-added properties such as regular spherical geometry, high mechanical properties, low dust, good wear-resistance, and good liquidity. While impregnated with transition metal chloride, the impregnated MCBs display outstanding breakthrough capacity of 111.4 mg/g for NH3 adsorption at 30 °C with a relative humidity of 80%. It is found that the type of transition metal chloride and their loading amount notably determine the adsorption performance. Moreover, the adsorption behavior is also determined by the process parameters such as humidity and NH3 concentration. The excellent adsorption performance is mainly due to the well-developed mesoporous structure of MCBs, which allow the uniform dispersion and immobilization of transition metal chlorides within their channels, while the residual mesoporous channel provides access to fast NH3 diffusion. [ABSTRACT FROM AUTHOR]