Selective Reduction of NO with CO Over Titania Supported Transition Metal Oxide Catalysts

• Published in: Catalysis letters 2008-04, Vol.122 (1-2), p.37-42
• Main Authors: Sreekanth, Pavani M., Smirniotis, Panagiotis G.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Catalytic activity; Catalytic converters; Chemistry; Chemistry and Materials Science; Chromium; Copper; Exact sciences and technology; General and physical chemistry; Industrial Chemistry/Chemical Engineering; Iron; Manganese; MOX; Nickel; Organometallic Chemistry; Oxidation; Physical Chemistry; Selective catalytic reduction; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium dioxide; Transition metal oxides; Transition metals
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-007-9365-5

A series of transition metal oxides promoted titania catalysts (MO x /TiO 2 ; M = Cr, Mn, Fe, Ni, Cu) were prepared by wet impregnation method using dilute solutions of metal nitrate precursors. The catalytic activity of these materials was evaluated for the selective catalytic reduction (SCR) of NO with CO as reductant in the presence of excess oxygen (2 vol.%). Among various promoted oxides, the MnO x /TiO 2 system showed very promising catalytic activity for NO + CO reaction, giving higher than 90% NO conversion over a wide temperature window and at high space velocity (GHSV) of 50,000 h −1 . It is remarkable to note that the catalytic activity increased with oxygen, up to 4 vol.%, under these conditions leading primarily to nitrogen. Our TPR studies revealed the presence of mixed oxidation states of manganese on the catalyst surface. Characterization results indicated that the surface manganese oxide phase and the redox properties of the catalyst play an important role in final catalytic activity.