Photocatalytic valorization of ethanol and glycerol over TiO2 polymorphs for sustainable hydrogen production

• Phase composition of TiO2 materials can be tuned changing the urea/Ti molar ratio during synthesis by thermal hydrolysis.
• H2 production has been tested using ethanol or glycerol aqueous solutions as sacrificial agents.
• Maximum H2 productivity on mass bases is observed for anatase-rich materials.
• Brookite shows the higher H2 production rate when normalized with respect to the surface area.

Photocatalytic reforming of renewable raw materials in aqueous solutions represents a valid possibility for the valorization of wastes from agricultural and industrial processes. In this study, we prepared TiO2 materials with different phase compositions by changing the urea/Ti molar ratio employed during the hydrothermal preparation method. After deposition of Pt nanoparticles, the photocatalytic H2 production was investigated using ethanol and glycerol as sustainable sacrificial agent. While anatase/rutile nanocomposites showed poor catalytic activity, the anatase/brookite nanocomposites showed more promising performances. Specifically, the anatase-rich materials showed the best performances on mass bases. When normalized with respect to the surface area of the photocatalysts, the activity continuously increased with the brookite content, indicating that exposed facets of brookite possess an intrinsic higher activity than that of the other polymorphs.

Figure optionsDownload high-quality image (367 K)Download as PowerPoint slide