A system and method are disclosed for regenerating an oxidation catalyst used in an aftertreatment system of a multifuel internal combustion engine. According to at least one aspect of the present disclosure, recirculated exhaust gas is employed to enable recovery periods in which the engine generates oxygen-depleted exhaust to desulfate and deoxidize the oxidation catalyst. In certain embodiments, the system may include an exhaust gas recirculation system with a cooler and regulation valve to introduce exhaust gas into the engine.