Natural gas can be reformed to syngas (CH 4 1 H 2 O 5 CO 1 3H 2 ), at temperatures above 8508C. Membrane catalytic reformers can provide high CH 4 conversions at temperatures below 6508C, by separating H 2 from the reactive mixture. Traditional Ni-based catalysts suffer from low activity at low temperatures and deactivate rapidly by coking, particularly at low steam/carbon ratios. In this study, an ultralow loading (0.15 wt %) Ru/c-Al 2 O 3 catalyst was implemented in a lab-scale membrane reformer, using a supported 5lm Pd-Ag film membrane. Methane conversions above 90% were achieved at 6508C, 8 bar, and H 2 O/CH 4 5 2, 3 with contact times of ca. 10 s. The system generated up to 3.5 mol of ultrapure H 2 per mol of CH 4 fed, with a maximum power density of 0.9 kW/L. No significant deactivation was observed after 200 h time on stream, even when using low H 2 O:CH 4 ratios.