ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Fe- and Cu-oxides supported on γ-Al₂O₃ as catalysts for the selective catalytic reduction of NO with ethanol. Part I: catalyst preparation, characterization, and activity

Denis Worch, Wladimir Suprun, and Roger Gläser

Institute of Chemical Technology, Universität Leipzig, Linnéstraße 3, 04103, Leipzig, Germany

E-mail: roger.glaeser@uni-leipzig.de

Abstract: Fe- and Cu-oxides supported on γ-alumina (γ-Al₂O₃; metal loading of 3 mass %) were investigated as alternative catalysts to the conventional Ag-based system in the selective catalytic reduction of NO with ethanol (EtOH-SCR). The catalysts were characterized by elemental analysis, N₂ sorption, X-ray diffraction, temperature-prgrammed desorption of NH₃, temperature-programmed reduction with H2, diffuse reflectance UV-VIS (DR-UV-VIS) spectroscopy, and compared with 3 mass % Ag/γ-Al₂O₃ as a reference catalyst. Catalytic experiments were carried out between 423 K and 773 K in the steady state and by temperature-programmed surface reaction (TPSR) experiments. For all catalysts, the highest NO conversion (900 ppm (ppm = parts of the mixture component per million parts of all mixture components) NO, 900 ppm EtOH, 0.5 vol. % H₂O, 4 vol. % O₂ in He) was found at 573 K. While 84 % of NO were converted over the Ag-based catalysts, only 20–60 % NO conversion was observed for the Fe- and Cu-containing catalysts. Total oxidation of ethanol as an unwanted side reaction occurs over 3 mass % Cu on γ-Al₂O₃ already at 573 K, whereas the highest activity of 3 mass % Fe on γ-Al₂O₃ for this conversion was reached at 743 K. For lower temperatures, partial oxidation of ethanol leads to organic by-products which can act as active intermediates in EtOH-SCR. TPSR experiments show that ethanol reacts over both the Fe- and the Cu-based catalysts to organic by-products, such as ethene or acetaldehyde, which affect the EtOH-SCR reaction.

Keywords: SCR-DeNO x – ethanol – acetaldehyde – supported metal oxides – Ag/γ-Al2O3 – environmental catalysis

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0533-3

Chemical Papers 68 (9) 1228–1239 (2014)