The performance of a unit cell (50 mm x 50 mm) equipped with a modified direct internal reformer is investigated by comparison with that of a traditional reformer in which the reforming catalyst is loaded constantly throughout the cell. The channel depth ratio of the inlet and outlet in the modified reformer is 1:2, and the depth of the channel increases linearly to the outlet position. Half the amount of the reforming catalyst in the outlet position is loaded in the inlet position. The unit cell with a modified reformer shows good stability in terms of open-circuit voltage and its overall electrical resistance is 94% that of a unit cell equipped with a traditional reformer. In long-term cell performance tests with a cell utilization of 40%, the modified reformer unit cell shows greater durability; it provides 40 more hours of performance than the cell with a traditional reformer. Furthermore, the average temperature of the outlet gases from the modified reformer. unit cell over the course of 200 h is lower than that of a traditional reformer unit cell by 8 degrees C. The potassium and lithium poisoning levels of catalysts in the modified reformer are respectively, 54 and 45% of those in a traditional reformer. The results might be attributed to the different loading amount of the reforming catalyst, leading to a more uniform dispersion of the reforming reaction throughout the cell. This dispersion of the reforming reaction may also lead to the uniform dispersion of other reactions throughout the cell, improving the overall cell performance. (c) 2005 Elsevier B.V. All rights reserved.