A method and an apparatus of reacting reaction components. The method comprises electro-chemically reacting reaction components on opposite sides of at least one membrane with at least one catalyst encompassing a respective volume. In another embodiment, the method includes conducting electrolysis, such as electrolysis of water. The apparatus includes at least one membrane with first and second sides encompassing a respective volume. The apparatus further includes at least one catalyst coupled to the first and second sides to electro-chemically react reaction components on the first and second sides in gaseous communication with the at least one catalyst, and a cover coupled to the at least one membrane to separate flow paths on the first and second sides.