In-pore synthesis of ZnCO\(_3\) in various adsorbents for NH\(_3\) and SO\(_2\) adsorption

A highly porous adsorbent capable of broad spectrum filtration of toxic industrial chemicals (TICs) is necessary for many civilian and military applications. To promote the gas adsorption of TICs such as NH\(_3\) and SO\(_2\), a biphasic carbon silica composite (CSC) and other single phase carbonaceous and siliceous materials functionalized with sparingly soluble ZnCO\(_3\) are considered. The adsorption capacities of these substrates functionalized via both in-pore synthesis and a wet impregnation have been measured with very low concentrations of both TICs in a balance of helium. Along with capacity performance, the functionalized materials have been characterized using X-ray diffraction, microscopy, and porosimetry techniques. Results show successful incorporation of a well dispersed ZnCO\(_3\) phase when incorporated via in-pore synthesis. All ZnCO\(_3\) functionalized materials enhance adsorption capacities compared to impregnant-free substrates. Characterization results show reduced pore volumes and surface areas of functionalized materials while maintaining structural integrity. In order to target both adsorbates effectively, in-pore synthesis of ZnCO\(_3\) on CSC provides high adsorption performance with NH\(_3\) and SO\(_2\) capacities of 4.2 and 0.59 mol/kg, respectively.