Density functional theory combined thermodynamic study of the lead species adsorption on transition-metal-doped carbon materials: Intrinsic-intensified schemes

To tackle the lead (Pb) pollution in flue gas, the development of efficient adsorbents has become the desirable approach. However, the construction of adsorbent structure–activity relationship network remains challenging due to lacking the deep understanding of enhancement schemes for adsorbent modification. Here, the interaction mechanisms of transition-metal-modified carbon materials with Pb species and their intrinsic-intensified schemes were investigated by density functional theory and thermodynamics calculations, considering the effects of flue gas composition and temperature. Compared with the unmodified surface, the stability and selectivity of the modified surfaces for the adsorption of Pb species are increased dramatically and with good CO2 and HCl resistances. According to thermodynamic results, the Fe/CM and Mn/CM surfaces possess steady adsorption stability for Pb species from 100℃ to 400℃. Thereby, transition metal modification may complement carbon materials with properties such as efficiency enhancement, chlorine resistance, and wide temperature. Additionally, the Mn/CM exhibits superior properties than the Fe/CM, attributed to the lower orbital energies, stronger bonding interactions, and lower spatial resistance of the Mn and Pb species. Overall, this study provides an improved understanding for the development of efficient Pb control technology.