Effect of Calcination Temperature on Soot Oxidation Activity by Pure and La-doped CeO₂ (Ce_1−xLa_xO₂) Synthesized via Orange Peel Extract

To control air pollution from diesel engines, the pure and La-doped CeO₂ (Ce_1−xLa_xO₂) materials have been synthesized using orange peel extract (green synthesis process) for soot oxidation activity. The identification of phase and morphology was made by XRD (X-Ray diffraction) and FE-SEM (Field Emission Scanning Electron Microscopy), respectively. The thermogravimetric-differential scanning calorimetry (TGA–DSC) analyzer has tested the soot oxidation activity by measuring the weight loss of pure and La-doped CeO₂ in soot (loose contact) with temperature. The Fourier Transform Infrared (FT-IR) spectroscopy has also been performed to identify the functional group in the synthesized samples. The materials were calcined at 500 and 550 °C, and the effect of change in calcination temperature for soot oxidation activity has been observed. Soot oxidation under loose contact conditions was tested and found in the range of 380–401 °C for the materials calcined at 500 °C and between 370 and 403 °C for materials calcined at 550 °C.