Combustion synthesis of MnOx/CeO2/Al2O3 catalyst

Sinteza oksidnih prašaka koji se potom koriste u katalizatorima za kontrolu emisije ispušnih plinova se može provesti na različite načine: sintezom sagorijevanjem, sol-gel postupkom, samopropagirajućom visokotemperaturnom sintezom itd. U ovom su radu različiti oksidni katalizatori pripravljeni sintezom sagorijevanjem. Kao gorivo se koristila aminokiselina glicin. Temperatura tijekom sinteze se pratila pirometrom. Dobiveni produkti su termički obrađeni nakon sinteze te su karakterizirani rendgenskom difrakcijskom analizom (XRD), infracrvenom spektroskopijom s Fourierovom transformacijom (FTIR) i termogravimetrijskom analizom (DTA/TGA). Katalitička aktivnost dobivenih katalizatora je ispitana u procesu oksidacije čađe. Utvrđeno je da je dio uzoraka nakon sinteze amorfan dok u preostalima dolazi do kristalizacije CeO2, γ-Al2O3, Mn3O4, CuO i AlCeO3. Nakon termičke obrade pri 800 °C tijekom 2 h u uzorcima dolazi do dodatnih faznih promjena od kojih je najvažnija raspad AlCeO3 na CeO2 i γ-Al2O3. Svi uzorci kataliziraju oksidaciju čađe.Synthesis of oxide powders used in emission control can be conducted using various methods: combustion synthesis, sol-gel method, self-propagating high-temperature synthesis etc. Various oxide powders were synthesized via combustion synthesis. Amino acid glycine was used as a fuel. Pyrometer was utilized for temperature monitoring during the synthesis. Obtained products were thermally treated and then characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and thermo-gravimetric analysis (DTA/TGA). Catalytic activity of acquired catalysts was examined via soot oxidation. It was established that part of the samples after synthesis is amorphous, while in the remaining ones crystallization of CeO2, γ-Al2O3, Mn3O4, CuO and AlCeO3 occurs. After heat treatment at 800 °C for 2 h, additional phase changes occur in the samples, the most important of which is the decomposition of AlCeO3 into CeO2 and γ-Al2O3. All samples catalyze the soot oxidation