Functionalization of activated carbon fiber mat with bimetallic active sites for NH3 and H2S adsorption at room temperature

Abstract

Simultaneous removal of NH3 and H2S at room temperature is of paramount significance for industrial production safety and environmental protection, which has received considerable attention recently. However, single metal compound modification is difficult to achieve highly efficient co-removal performance for NH3 and H2S. Herein, a series of adsorbents with metal chlorides and metal oxides simultaneously loaded in the activated carbon fiber mat were prepared and applied to the NH3 and H2S removal with high efficiency at room temperature. The obtained ACF-NiCl2-MgO possesses large surface area, hierarchical porous structure, as well as uniform dispersion of bimetallic active sites. The advanced porous architecture helps to ensure consistent dispersion of metallic active sites remaining residual channel for the capture of gas molecules. The metal salts facilitate the deamination ability by complexation with NH3, while metal oxides promote the desulfurization ability by chemical adsorption of H2S. The incorporation of metal chlorides and metal oxides significantly improves the adsorption performance of NH3 and H2S. Consequently, the NH3 adsorption capacity of ACF-NiCl2-MgO achieves 22.5 mg NH3/g, and the breakthrough sulfur capacity is as high as 209.2 mg H2S/g. This work provides a new method to design high-capacity binary metal compounds modified activated carbon-based adsorbents for the co-removal of NH3 and H2S at room temperature.