Low-Temperature Thermal Remediation of Naphthalene-Contaminated Soil Using Cu–CeOx/TiO2 Trimetallic Catalysts
Traditional soil thermal remediation requires high temperatures (>300 °C), which can damage soil structure, increase energy consumption, and elevate carbon emissions. This study developed a Cu–CeOx/TiO2 trimetallic catalyst to enable low-temperature thermal remediation of naphthalene-contaminated soil. Using nano-TiO2 as a support, catalysts with varying Cu/Ce ratios were prepared via impregnation-calcination. Material characterization (XRD, TEM, XPS, etc.) revealed that Cu and Ce incorporation induced crystal defects in TiO2, enhancing lattice oxygen activity and electron mobility, thereby generating more oxygen vacancies and hydroxyl radicals. Performance evaluation using a TGA-GC-FTIR-MS platform showed that the catalyst with Cu:Ce = 1:1 achieved the best remediation efficiency, reducing the thermal remediation temperature from 250 °C to 211.5 °C and increasing the removal rate by an average of 19.49% compared to the non-catalyst group at the same temperature. The catalyst facilitated stepwise degradation of naphthalene into smaller organic molecules (alcohols, carboxylic acids, aldehydes) and ultimately into H2O and CO2. This work demonstrates that Cu–CeOx/TiO2 significantly lowers the energy demand of thermal remediation, offering a promising approach for low-carbon remediation of organic-contaminated soils.