TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The plate assembly includes plates, or corrugated plates (2A-2C). The compliant baffle is positioned between at least first and second plates of the plates to form sections in the reformer. The sections include an inlet section (102) communicating with the inlet port, an outlet section communicating with the outlet port, and a turn section (103) from the ends of the first and second plates. The inlet and outlet ports are located on the same first face of the enclosure. The plates include a third plate in the turn section that abuts the ends of the first and second plates. The first and second plates extend from the first face of the enclosure in adjacent relationship in the enclosure to short of the opposite second face of the enclosure. The compliant baffle extends between abutting surfaces of the first and second plates. It extends between the abutting surfaces of the first and third plates and a portion of the abutting surfaces of the second and third plates. The inlet section is along the length of the first plate. The outlet section is along the length of the second plate. The first and second plates are rectangular. The third plate is triangular. A first inclined surface of the third plate abuts with an inclined surface of the first plate and a first inclined surface of the second plate. A second inclined surface of the third plate adjacent to the first inclined surface of the third plate abuts with a second inclined surface of the second plate. The baffle extends between the abutting surfaces of the second and third plates beginning at the first inclined surface of the second plate, and ends short of the end of the second inclined surface of the second plate. The plate supports the catalyst such that the inlet section is devoid of catalyst. The turn section and a return section (104) contain the catalyst. The catalyst in the turn and return sections varies in a predetermined manner along the flow path. The entry of the turn section is devoid of catalyst. The path includes an inlet section communicating with the inlet port, a return section communicating with the outlet port, and a turn section connecting the inlet section and the return section. A portion of the baffle at the interface of the turn and return sections is first angled away from the corner (105) of the turn section at the interface of the turn and return sections, and is then angled in the direction of the corner. The baffle comprises two segments, where a first segment separates the inlet section from the return section and a second segment partially separates the turn section from the return section. The baffle seals the path for gas flow to prevent gas leaks along the path. It is configured to direct the flow of gas to a predetermined region of the flow path. The predetermined region is in the corner of the reformer at the end of the turn section of the path. The catalyst varies in an amount along the path that is U-shaped. The reformer is devoid of catalyst through the inlet section of the reformer and then varies in a predetermined manner in the remainder of the turn section and in the return section of the reformer.Preferred Material: The baffle is made from a soft material for a high-temperature reducing atmosphere. It is preferably made from one or more of ceramic paper material, rope, yarn, and a material compatible with a high-temperature reducing atmosphere.