SO3 decomposition over CuO–CeO2 based catalysts in the sulfur–iodine cycle for hydrogen production

The effect of several catalyst supports with large specific surface area (such as SiC, Al 2 O 3 , SiC–Al 2 O 3 –ball, and SiC–Al 2 O 3 ) on catalytic activity was evaluated in this study. CuO–CeO 2 supported on SiC–Al 2 O 3 exhibited high stability and activity, which was considerably close to the thermodynamic equilibrium curve at 625 °C during the stability test for 50 h. The SO 3 decomposition temperature decreased from 750 °C to 625 °C. SiC–Al 2 O 3 contained numerous micropores and mesopores and had a large specific area, indicating strong adsorption, as determined by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption measurement. X-ray photoelectron spectroscopy (XPS) revealed that the surface of SiC–Al 2 O 3 consisted of Al 2 O 3 , SiC, and SiO 2 and that the cerium oxide surface had the largest number of defects. Temperature-programmed reduction (H 2 -TPR) results indicated that the cerium–copper oxides on the surface of powdered SiC–Al 2 O 3 had the strongest redox potential and that CuO had the lowest reduction temperature.