Three issues are most critical in fuel processors which are integrated with polymer electrolyte membrane (PEM) fuel cells for power generation: the steam reformer configuration, which must ensure very rapid heat transfer to the reformation zone, the development of highly active catalysts for the water-gas shift (WGS) reaction and the development of highly selective catalysts for the methanation reaction. The heat-integrated wall reactor (HIWAR), in either the tubular or the plate form, which offers very rapid heat exchange between a combustion and a reformation zone, is proposed. This configuration results in high efficiency and compact design. Platinum catalysts supported on a "reducible" metal oxide such as TiO2 exhibit high WGS activity, which can be further improved with the addition of alkali or alkaline earth promoters. Titania-supported ruthenium catalysts are capable of completely and selectively methanate CO in the presence of excess CO2, provided that catalyst characteristics are optimized and operating conditions are properly selected. Integration of the three developments can result in efficient power generation systems.