TECHNOLOGY FOCUS - AGRICULTURE - Preferred Components: The impurity comprises a herbicide, or a pesticide.    TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The impurity comprises a bacteria or a protein.    TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Electrode: The electrode is capable of oxidizing hydrogen gas. The electrode further comprises a current collector. The current collector has a surface area of 0.01-300 m2/g. The second metal type has an association constant of less than or equal to 1x 10-3 M-1. The third metal type is selected to de-alloy from the catalytic material. The third metal is selected to de-alloy from the catalytic material under set conditions at least about 2 times the rate of any de-alloying of the first metal type and the second metal type under the conditions, so as to increase the surface area of the electrode exposable to the electrolyte. The third metal type is selected such that at least 1% of the third metal is de-alloyed following formation and/or operation of the electrode where the current density of the electrode has neither decreased nor increased by not greater than 10% over a period of 2 hours under essentially constant electrochemical conditions. The photoactive composition comprises a photovoltaic cell, a triple-junction a-Si photovoltaic cell, a semiconductor, or a p-type semiconductor photocathode.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalytic material comprises or consists essentially of nickel and molybdenum. The additive and/or the anionic species is selected from forms of phosphate, forms of sulfate, forms of carbonate, forms of arsenate, forms of phosphite, forms of silicate, and forms of borate, or the additive and/or the anionic species are anionic species phosphorus, where the anionic species comprises phosphorus selected from HPO4-2, H2PO4-2, PO4-3, H3PO3, HPO3-2, H2PO3-2, or PO3-3. The catalytic material is associated with the current collector. The current collector comprises at least one of a metal, a metal oxide, or a metal alloy. The impurity or additive is present in a concentration of about 0.05 M. The first metal type is nickel (Ni), the second metal type is cadmium (Cd), and the third metal type is molybdenum (Mo). The anionic species is not oxide ions or hydroxide ions. The impurity comprises a metal or an inorganic compound. Preferred Method: The hydrogen gas is produced at an absolute value of the overpotential that is less than or equal to 0.2 V at an electrode current density of at least 1 mA/cm2. The impurity is present in an amount of less than or equal to 1000 ppm.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The impurity comprises an organic material, or a small organic molecule.    TECHNOLOGY FOCUS - PHARMACEUTICALS - Preferred Components: The impurity comprises a pharmaceutical compound. EXAMPLE - No suitable example given.