Abstract

This study evaluates the effect of synthesis mode and La-dopant incorporation on the performance of CeO2-based materials for CO2 capture. Materials were prepared by conventional autoclave and microwave-assisted hydrothermal treatments to compare their efficacy. Microwave-assisted synthesis enables rapid and uniform volumetric heating, accelerating nucleation and crystal growth, consequently shortening synthesis time. Samples were characterized by powder X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy- Energy-Dispersive X-ray Spectroscopy (SEM-EDS), Brunauer-Emmett-Teller (BET) analysis for surface area and pore volume, alongside CO2 adsorption measurements at 273 K. Microwave irradiation yielded CeO2 with smaller crystallites and higher surface area (107 m2 & sdot;g- 1) compared to the conventional hydrothermal method. The corresponding CO2 uptake for the microwave-assisted materials was 1.21 mmol & sdot;g- 1. Furthermore, La-doped samples exhibited stronger basic sites and altered Ce4+/Ce3+ ratios, favouring the formation of bidentate and polydentate carbonates. CO2 adsorption data correlated better with the Freundlich model, and the adsorption kinetics were best described by the pseudo-second-order model. The results demonstrate that microwave-assisted hydrothermal synthesis effectively tailored the surface properties of CeO2-based materials, enhancing both interaction strength with CO2 and overall CO2 adsorption capacity.