High-purity hydrogen to be fed directly to a PEMFC was produced by carrying out natural gas steam reforming under moderate operating conditions in a Pd-Au composite membrane reactor packed with a commercial Ni-based catalyst. The Pd-Au composite membrane with a thickness of approximately 12 mu m was fabricated by using both electroless and electroplating techniques to deposit Pd and Au layers, respectively, over a porous stainless-steel support. After annealing, the membrane showed a hydrogen permeance of 1.30 x 10(-3) mol/s-m(2)-Pa-0.5 at 450 degrees C, and near-infinite ideal selectivity of H2/Ar at pressures lower than 300 kPa and at temperatures lower than 400 degrees C.The natural gas reforming reaction was performed at 450 degrees C with a steam-to-methane ratio of 3.5 and gas hourly space velocity of 2600 h(-1)at different operating pressures varying from 100 kPa to 300 kPa. As a comparison, the steam methane reforming reaction was also carried out at the same operating conditions. The natural gas reforming reaction showed better performance than the steam methane reforming reaction and reached > 80% conversion of the higher hydrocarbons and almost 65% of hydrogen recovery at 450 degrees C and 300 kPa. High-purity hydrogen was obtained in all the experimental tests. No coke formation was observed. Post-reaction analysis of the membrane is discussed via scanning electron microscope and energy-dispersive X-ray spectroscopy.