Catalytic oxidation of lignite by Pt/TiO2 can enhance cadmium adsorption capacity.

Addressing global warming necessitates innovative strategies in fossil fuel management. This study evaluates lignite, a low-rank coal with limited calorific value, exploring applications beyond its use as fuel. Utilizing Pt/TiO 2 catalytic oxidation, the research aims to enhance the cadmium adsorption capacity of lignite in wastewater. Lignite, treated with 0.5% Pt/TiO 2 at 125 °C for 2 h, demonstrated a threefold increase in cadmium adsorption capacity. Characterization using TGA-DSC confirmed the modification process as exothermic and self-sustainable. Spectroscopic analysis and Boehm titration revealed significant alterations in pore structure, surface area, and oxygen-containing functional groups, emphasizing the effectiveness of catalytic oxidation. Adsorption mechanisms such as complexation, cation exchange, and cation-π interactions were identified, enhancing Cd adsorption. Techniques, including the d-band model, H 2 -TPR, and O 2 -TPD, indicated that dissociative adsorption of molecular O 2 and the subsequent generation of reactive oxygen species introduced additional oxygen-containing functional groups on the lignite surface. These findings provide essential strategies for the alternative use of lignite in environmental remediation, promoting sustainable resource utilization and enhancing cost-effectiveness in remediation processes. This study innovates in using lignite to reduce cadmium (Cd) contamination in wastewater. Employing Pt/TiO 2 catalytic oxidation, lignite is transformed, enhancing its cadmium adsorption capacity. This process, being exothermic, contributes to decreased energy consumption. The approach not only mitigates the hazardous impacts of cadmium but also aligns with sustainability by reducing greenhouse gas emissions and energy use, showcasing a multifaceted environmental advancement. [Display omitted] ● Pt/TiO 2 catalytic oxidation triples lignite's cadmium adsorption capacity. ● The catalytic process is exothermic and self-sustaining, reducing energy use. ● Adsorption mechanisms include complexation, cation exchange, and cation-π interactions. ● O 2 - and O- species facilitate the generation of oxygen-containing groups on lignite. [ABSTRACT FROM AUTHOR]