Hydrothermal synthesized kaolin group lamellar/spongy aluminosilicates for enhanced lead vapor capture.

Developing high-temperature-resistant adsorbents with superior porous properties is crucial for safely disposing of heavy metal-containing solid waste via pyrolysis. We synthesized aluminosilicates hydrothermally and observed that acidic conditions, especially HCl (pH=2.6), favored sponge-like mineral (NC2.6) formation with a specific surface area of 500.31 m²/g and pore volume of 0.986 cm³ /g, while alkaline conditions (pH=12.0) promoted spherical particle growth. NC2.6 exhibited higher adsorption capacity compared to kaolinite and halloysite in the PbCl vapor adsorption, reaching a maximum of 137.68 mg/g at 700 ℃ (75.91 % stable). We examined the effect of CO and HO on adsorption efficiency and explored the mechanisms using DFT and GCMC simulations. From GCMC results, CO negatively impacted PbCl adsorption due to competitive adsorption, while HO increased adsorption content (144.24 mg/g at 700 ℃) by converting PbCl into oxides. DFT revealed the presence of CO enhanced the adsorption stability of PbCl via the formation of covalent bonds between O in CO and Pb, and active O on the aluminosilicate surface. HO increased PbCl adsorption energy, as O in HO occupied an active Al that originally formed a covalent bond with Cl, while the H formed a weak hydrogen bond with this Cl.