A product for depollution of exhaust gas includes a mixture of an additive for treating particles and a reductant for eliminating nitrogen oxides (NOx). The reductant can contain ammonia or a compound generating ammonia by decomposition, or a hydrocarbon from a hydrocarbon-containing substance, oxygenated or not. The addictive for treating particles can be an additive for catalyzing particle oxidation.

The present invention describes a fluid which is suitable for the decontamination of heat engines which can carry out, at the same time, both the catalytic reduction of oxides of nitrogen (NOx) contained in exhaust gases and assist in the regeneration of the particulate filter (PF). The invention also describes several embodiments of said fluid consisting of producing an oil-in-water type emulsion.