NOVELTY - The unit (36) follows the fuel cell system (28). Effluent gas from the fuel cell (30) and/or reformate from the reformer (29) is prepared with an operational substance for after-treatment of the exhaust gases.    USE - Effluent gas treatment system for vehicle reformer and fuel cell.    ADVANTAGE - This design simplifies in comparison with prior art, whilst enabling adequate preparation of the treatment substance (reductant mixture) for the exhaust gases. The ammonia may be produced using an ammonia catalyst, avoiding carrying hazardous ammonia as such, especially on passenger vehicles.    DETAILED DESCRIPTION - The after-treatment substance is ammonia and the treatment unit (36) is an ammonia catalyst. The inlet of the preparation unit for fuel cell effluent gas and/or reformate, is connected to the fuel cell system (28). Its outlet is connected to an NOx reduction catalyst (22). An SCR (selective catalytic reduction) catalyst (22) is employed. The treatment unit (36) outlet is also connected to the intermediate storage (46) vessel for ammonia, which is also connected to the reduction catalyst (22). The treatment unit (36) and ammonia intermediate storage vessel are connected to dosing units (40, 42), metering ammonia to the reduction catalyst (22). The fuel cell system also has a switched bypass line (48), connecting to the exhaust gas line of the after-treatment unit (10). The reduction catalyst is preceded by an oxidation catalyst (18) in the exhaust gas line from the engine (16). The fuel cell system is an auxiliary energy generator, supplying a functional unit with electricity, continuously or intermittently. The corresponding vehicle is also claimed.    DESCRIPTION OF DRAWING(S) - A block schematic diagram of the system appears.    after-treatment unit (10)    engine (16)    oxidation catalyst (18)    NOx reduction catalyst/SCR catalyst (22)    fuel cell system (28)    reformer (29)    fuel cell (30)    unit (36)    dosing units (40, 42)    vessel for ammonia storage (46)    bypass line (48)