Cerium–Copper–Manganese Oxides Synthesized via Solution Combustion Synthesis (SCS) for Total Oxidation of VOCs
Miguel Jose Marin Figueredo, Tahrizi Andana, Samir Bensaid, Melodj Dosa, Debora Fino, Nunzio Russo, Marco Piumetti
Abstract
Abstract A set of cerium–manganese–copper oxide catalysts with various foreign metal contents was prepared via the solution combustion synthesis (SCS). The catalysts were characterized by complementary techniques such as N 2 physisorption at − 196 °C, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), H 2 -temperature-programmed reduction (H 2 -TPR), O 2 -temperature-programmed desorption (O 2 -TPD) and X-ray photoelectron spectroscopy (XPS). Their catalytic activity was tested towards the VOC oxidation using ethylene and propylene as probe molecules. As a whole, it has been observed that the Ce 55 Mn 45 sample (Mn 45 at.%), containing MnO x clusters interacting with the ceria phase, was the most active catalyst for propylene oxidation, exhibiting a complete conversion at 250 °C. On the other hand, the ternary oxide catalyst (Ce 55 Mn 22.5 Cu 22.5 with Mn = 22.5 at.% and Cu = 22.5 at.%) has exhibited the best results for the oxidation of ethylene. These findings suggest that the co-presence of different active phases on the catalytic surface may have a beneficial (multiplicative) role on the whole reactivity. Finally, the most active powder catalysts were wash-coated in a SiC monolith and tested in a bench-scale reactor. As a whole, the catalyzed monoliths performed the complete oxidation of either ethylene or propylene at lower temperatures (550 and 450 °C, respectively) than those required to thermally decompose these molecules. Graphic Abstract