Supported LiNO3 catalysts. Soot combustion.

MARIA LUCIA RUIZ; MARTA ISABEL PONZI; ENRIQUE RODRÍGUEZ CASTELLÓN; ANTONIO JIMÉNEZ LÓPEZ; ILEANA DANIELA LICK; ESTHER NATALIA PONZI

Madrid, España

Simposio; International Symposium on "Catalysis for Clean Energy and Sustainable Chemistry"; 2008

Diesel engines are widely used for several applications since they combine inexpensive fuel, high durability and low maintenance cost. The disadvantage of this type of engines is that they generate dangerous pollution for human health [1]. Principal contaminants emitted by this type of engines are nitrogen oxides and soot [2]. When a catalytic reaction is of the solid-solid-gas type, as it occurs in the combustion of soot with O2/NO in presence of a solid catalyst, the contact between the catalyst and the soot is a key factor for the reaction that occurs in an interface soot-catalyst-O2. Catalysts that are able to create a well contact between soot and the active phase are those based on molten salts, Cs2SO4-V2O5, CsVO3-MoO3, Cs2O-V2 [3-5] and LiNO3, KNO3, CsNO3 [6,7]. An additional property presented by catalysts containing alkaline metals nitrates is that nitrate can be reduced to nitrite during the catalytic process [8, 9]. 2 MNO3 + C(soot)      à 2 MNO2 + CO2                 (1) 2 MNO2 + O2                         à 2 MNO3                            (2) In this work, catalysts containing lithium nitrate impregnated on hydrated zirconium oxide, zirconium oxide and silica are investigated in the catalytic combustion of soot.