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

Hu J, Han B, Butterly C R, Zhang W, He J-Z, & Chen D. “Catalytic oxidation of lignite by Pt/TiO2 can enhance cadmium adsorption capacity.” Journal of Hazardous Materials, 465, 133207. DOI: 10.1016/j.jhazmat.2023.133207 

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/TiO₂ catalytic oxidation, the research aims to enhance the cadmium adsorption capacity of lignite in wastewater. Lignite, treated with 0.5% Pt/TiO₂ 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, H₂-TPR, and O₂-TPD, indicated that dissociative adsorption of molecular O₂ 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.