An endothermic methanol steam reformer achieves optimal performance at a temperature of about 240 degrees C. A polybenzimidazole (PBI) membrane fuel cell was operated exothermically at 160 degrees C-200 degrees C. To better couple the lower temperature fuel cell to the higher temperature steam reformer, a two-stage temperature steam reformer to integrate into the PBI membrane fuel cell system is proposed. The reformer optimizes thermal management and increases the system efficiency. A steam reformer with a CuO2/ZnO2 catalyst and a catalyst combustor that produces hydrogen and heat was developed. The first stage temperature of 190 degrees C is designed to be integrated with the single PBI membrane fuel cell, to utilize the fuel cell heat production. The second stage reformer utilizes the fuel cell tail gas to finally heat the reformer to 240 degrees C. Experimental results from the two-stage temperature reformer integrated with a PBI fuel cell system are compared with a single temperature reformer and fuel cell system operating at 200 degrees C. The two-stage temperature reformer and fuel cell system has an improved hydrogen conversion rate, hydrogen flow rate, and fuel cell performance. The reformed gases at optimal operating conditions consisted of 74.84% H-2, 1.30% CO, and 22.51% CO2. The maximum PBI membrane fuel cell power density was 0.25 W/cm(2), which is 25% greater than for the single temperature reformer. The two-stage temperature reformer can also increase fuel cell system efficiency by improving thermal management. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.