Exhaust gas pollution control fluid comprising a soluble basic metal carbonate, process for preparing same and use thereof for internal- combustion engines

The invention relates to a fluid suited for depollution of exhaust gas, notably in internal-combustion engines, allowing both to perform catalytic reduction of the nitrogen oxides (DeNOx) contained in the exhaust gas and to provide particulate filter (PAF) regeneration aid. The fluid is a homogeneous aqueous solution of a reductant or a reductant precursor for the DeNOx process, and it comprises a metallic additive for catalyzing the oxidation of exhaust gas particles. This metallic additive is a basic metal carbonate soluble in said aqueous solution. The invention also describes the preparation method and the use thereof for the depollution of exhaust gas of internal-combustion engines.