Cerium–Copper–Manganese Oxides Synthesized via Solution Combustion Synthesis (SCS) for Total Oxidation of VOCs

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