Dimethyl ether (DME) steam reforming was performed on some catalysts. Silica catalysts produced less hydrogen and carbon dioxide. On the other hand, large quantities of H-2 and CO2 Were produced from DME and water using alumina catalysts prepared by a sol-gel method, especially copper alumina catalysts. Other metal alumina catalysts prepared by the sol-gel method produced H-2 and CO2, but also produced large quantities of carbon monoxide. CO deteriorates anode Pt catalysts of polymer electrolyte fuel membrane cells, and cell performance is dramatically reduced. Our studies showed that copper is the best metal for the production of H-2 while producing less CO. gamma-Alumina, especially Lewis acid sites for DME hydrolysis into methanol, and active metals such as copper for methanol steam reforming to H-2 and CO2 are mixed and distributed well on the surfaces of catalysts prepared by the sol-gel method. Therefore, sol-gel catalysts produce H-2 and CO2 well from DME. Adding Zn and Pd to Cu/Al2O3 prepared by the sol-gel method improved H-2 production; in particular, Pd improved the activity under a low temperature of 250degreesC. Zn also improved H-2 production, but not as much as Pd; however, CO production was reduced. Cu-Zn/Al2O3 catalysts prepared by the sol-gel method are excellent DME steam reforming catalysts for high H2 production and less CO formation. (C) 2003 Elsevier B.V. All rights reserved.