Low-Temperature Thermal Remediation of Naphthalene-Contaminated Soil Using Cu–CeOx/TiO2 Trimetallic Catalysts

• • The optimal Cu:Ce ratio of 1:1 in Cu–CeOx/TiO2 lowered the thermal remediation temperature for naphthalene-contaminated soil from 250 °C to 211.5 °C, a reduction of 38.5 °C, directly cutting energy consumption and preserving soil structure. • • At identical temperatures, the catalyst-enhanced group achieved an average 19.49% higher naphthalene removal rate compared to the non-catalyst control, demonstrating significant catalytic activity enhancement. • • Material characterization confirmed that Cu and Ce doping induced crystal defects in TiO2, increasing oxygen vacancies and hydroxyl radical generation, which are critical for oxidative degradation of naphthalene at lower temperatures. • • The catalyst promoted stepwise degradation of naphthalene into alcohols, carboxylic acids, and aldehydes, ultimately mineralizing to H2O and CO2, with fewer by-products than the control, indicating a cleaner remediation pathway.