Development and characterization of Fe2O3 nanoparticles doped with Al2O3 / TiO2 for green hydrogen production

Iron oxide is an inexpensive raw material capable of producing hydrogen based on the water-splitting reaction. However, the reaction is limited by the active surface area available on the particle. In this study, Fe2O3 nanoparticles doped with Al2O3 and TiO2 oxide (95 wt% Fe2O3 - X wt% Al2O3 - (5-X) wt% TiO2; X = 2, 2.5 and 3) were prepared by a double coprecipitation method to obtain a single solid solution. The synthesis of a solid solution resulted in particles with higher porosity. The use of Al resulted in the formation of pores of approximately 3 μm, which effectively prevented grain growth. Conversely, the substitution of Ti ions increased the oxygen mobility, resulting in a higher hydrogen consumption at temperatures below 700 ◦C, leading to a deeperreduction reaction. Indeed, the reactivity of the particle surface was strongly influenced by the Al/Ti atomic ratio, and the Fe3Al2Ti formulation seems to be the most promising due to its compositional and morphological design to create an oxide functional ceramic for H2 production.