Highly effective, standalone gas-diffusion electrodes (GDEs) and the methods for their manufacture and test are disclosed, Nanocataiysis are directly bonded on a gas diffusion layer, so that the integrity of the catalyst layer holds without polymer electrolyte membrane, facilitating minimization of electronic, prottmtc, and diffusion resistances in the catalyst layer. The devised embodiments provide examples showing a facile hanging-strip method for testing the standalone GDEs in a solution electrochemical cell, which removes the mA-cm.sup.-2-scale mass transport limited currents on rotating disk electrodes to allow studies of reaction kinetics on single electrode over sufficiently wide current ranges (up to A cm.sup.-2) without mass transport limitation. Ultralow-Pi-content GDEs are fabricated as the cathode for hydrogen evolution in water eiectrolyzers and as the anode for hydrogen oxidation in hydrogen fuel cells. High performance GDEs with low loadings of platinum group metals are being developed for oxygen evolution reaction at the anode of water electrolyzers and for the oxygen reduction reaction at the cathode of fuel cells.
STATEMENT OF GOVERNMENT LICENSE RIGHTS
 The present invention was made with Government support under contract number DE-AC02-98CH10886 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.