Abstract: The present invention relates to a protective reformer device (10) for the protection of an anode section (112) of a fuel cell stack (110) against oxidizing damage during a heating-up process, having a gas duct (20) with a gas inlet (22) and a gas outlet (24) for conducting fuel gas from an anode feed section (120) of the fuel cell stack (110), wherein a catalytic converter section (30) is arranged in the gas duct (20) for a catalytic oxidation of at least part of the fuel gas into a protective gas for feeding to the anode section (112), wherein, furthermore, the gas duct (20) has a temperature control device (40) in thermally transmitting contact with the catalytic converter section (30) for an active temperature control of the catalytic converter section (30).

Abstract: The present invention relates to a fuel cell system (1a; 1b; 1c; 1d) comprising: at least one fuel cell stack (2) with an anode portion (3) and a cathode portion (4); a reformer-heat exchanger (5) with a cold side which is upstream of the anode portion (3) and forms a reformer (6) and a hot side which is downstream of the cathode portion (4) and forms a heat exchanger (7); and an afterburner (8) downstream of the heat exchanger (7) for combusting anode exhaust gas from the anode portion (3) and/or cathode exhaust gas from the cathode portion (4), the heat exchanger (7) being situated directly downstream of the cathode portion (4) and being in fluid communication with the cathode portion (4) by means of a cathode exhaust gas line (9) in order for the cathode exhaust gas to be fully conducted through the heat exchanger (7). The invention also relates to a method for controlling the temperature of a fuel cell system (1a; 1b; 1ce; 1d) according to the invention.