The effective capture or conversion of elemental mercury (Hg⁰), is the key scientific problem for controlling total mercury pollution in coal-fired power plants. In this work, the cerium chloride (CeCl₃) modified carbon aerogel (CA) was successfully synthesized via impregnation method. The as-prepared samples maintained the large specific surface area and excellent pore structure of CA, and the CeCl₃ was evenly dispersed, which can play a synergistic role in chemical adsorption and thermal catalysis to capture and oxidize the Hg⁰ effectively, and the Hg⁰ removal efficiency was greatly improved, up to 98 % at 120 °C. The enhanced Hg⁰ removal performance could be attributed to the surface active chlorine and cerium oxide (CeO₂) particle generated in the preparation process. Based on density functional theory (DFT), the mechanism of mercury removal was discussed in detail. This work would give a new insight for mercury and other heavy metal pollution control in coal-fired power plants.