Experimental study of Ni/CeO2 catalytic properties and performance for hydrogen production in sulfur–iodine cycle

The Ni/CeO2 catalysts with different calcination temperatures have been tested for hydrogen production in sulfur–iodine (SI or IS) cycle. TG-FTIR, BET, XRD, HRTEM and TPR were performed for catalyst characterization. It was found that the Ni2+ ions could be inserted into the ceria lattice. This brought about the strong interaction between Ni and CeO2 and the generation of oxygen vacancies. Perfect crystallites were formed in the catalysts. It was evident that there was a change in particle size and morphology as the calcination temperature increased from 300 to 900 °C. The Ni/CeO2 catalysts with different calcination temperatures showed better catalytic activity by comparison with blank yield, especially Ni/Ce700. A hypothetic mechanism of HI catalytic decomposition on Ni/CeO2 has been constructed. The two important reactive sites were assumed for HI catalytic decomposition.