Abstract: Provided is a PROX (preferential oxidation) reaction apparatus for a fuel cell, which includes a mixing chamber to which a reforming gas and a PROX air are introduced, a reforming gas supply tube disposed in the mixing chamber to supply a reforming gas, a heat exchange chamber connected to an upper portion of the mixing chamber, a disk disposed between the mixing chamber and the heat exchange chamber, a cooling water circulation module connected to the heat exchange chamber, and a PROX catalyst chamber disposed above the heat exchange chamber, wherein the reforming gas supplied through a lower portion of the mixing chamber performs multi-stage mixing while passing through the mixing chamber and the disk.

Abstract: Provided is a fuel reformer for a fuel cell system, which includes an autothermal reforming reactor having an autothermal reforming reaction catalyst and configured to produce a reforming gas with abundant hydrogen by using a hydrocarbon-based fuel, water and air, an ATO reactor configured to produce a high-temperature combustion gas by burning a fuel-containing tail gas discharged from a fuel cell stack, and an ATO heat exchanger configured to increase a temperature of a mixture of water and air supplied to the autothermal reforming reactor, by using the combustion gas produced by the ATO reactor.