PSA Citroën patent number FR2880657 entitled "Exhaust gas recirculation circuit" (with reformer and injection of hydrogen to promote combustion)
(...) It has been shown that an addition of hydrogen-rich gas (H2) to the combustion chamber intake manifold during exhaust gas recirculation reduces hydrocarbon emissions. unburned (HC), carbon monoxide (CO) and soot.
The power output of the engine is thus improved while limiting the emissions of carbon products.
In a manner known in itself, reforming the fuel is obtained by reacting fuel molecules with water and / or air to produce hydrogen according to the following chemical reactions ...
The following in the document.
Read more and debate: hydrogen injection into the fuel