A CPOx hydrocarbon reformer comprising a plurality of sequential reforming stages for generating reformate. The first stage comprises adjacent active and inactive flow channels. Only a portion of the surface is provided with catalyst. The active channels have low catalytic activity such that about one-quarter of the reactants passing through the first stage is catalyzed. Reactants flowing through the inactive channels cool the active channels, preventing bed erosion. The fast exothermic combustion reaction near the front edge of the catalyst produces largely water and carbon dioxide but little hydrogen. Endothermic reactions in the following stages produce hydrogen and carbon monoxide while consuming water, carbon dioxide, and the remaining hydrocarbon fuel and oxygen using steam- and dry-reforming. Preferably, the intermediate stage reacts about one-half of the fuel. The last stage is fully coated to react the remainder of the fuel, and catalyst activity is increased.