WO₃ and Ionic Liquids: A Synergic Pair for Pollutant Gas Sensing and Desulfurization

• Main Authors: Francesca D’Anna, Maria Luisa Grilli, Rita Petrucci, Marta Feroci
• Format: Article
• Language: English
• Published: MDPI AG 2020-04-01
• Series: Metals
• Subjects: WO₃; ionic liquids; gas sensor; pollutant gases; desulfurization
• Online Access: https://www.mdpi.com/2075-4701/10/4/475

This review deals with the notable results obtained by the synergy between ionic liquids (ILs) and WO₃ in the field of pollutant gas sensing and sulfur removal pretreatment of fuels. Starting from the known characteristics of tungsten trioxide as catalytic material, many authors have proposed the use of ionic liquids in order to both direct WO₃ production towards controllable nanostructures (nanorods, nanospheres, etc.) and to modify the metal oxide structure (incorporating ILs) in order to increase the gas adsorption ability and, thus, the catalytic efficiency. Moreover, ionic liquids are able to highly disperse WO₃ in composites, thus enhancing the contact surface and the catalytic ability of WO₃ in both hydrodesulfurization (HDS) and oxidative desulfurization (ODS) of liquid fuels. In particular, the use of ILs in composite synthesis can direct the hydrogenation process (HDS) towards sulfur compounds rather than towards olefins, thus preserving the octane number of the fuel while highly reducing the sulfur content and, thus, the possibility of air pollution with sulfur oxides. A similar performance enhancement was obtained in ODS, where the high dispersion of WO₃ (due to the use of ILs during the synthesis) allows for noteworthy results at very low temperatures (50 °C).