Towards hydrogen production using a breathable electrode structure to directly separate gases in the water splitting reaction

A novel electrode design to directly separate the gases and improve the efficiency of the water splitting reaction is described. In this work, platinum was used as a model catalyst, deposited on porous membranes with different pore size and shape. The O ₂ evolution rate was monitored at the gaseous side of these breathable electrodes. We show that the hydrophobic Goretex ^® membrane electrodes provide a highly efficient removal of the gases, breathing out 92% of expected O ₂ during water splitting, and thereby also largely avoiding the well known migration of oxygen to the cathode in the absence of a separator in the cell. The breathable structure is also shown to operate as a hydrogen electrode. The ability to separate the two gases, without the need for a separator, decreases gas cross-over and thereby enhances the coloumbic efficiency. Merging this approach with catalysts and photocatalysts of a variety of types e.g. non-precious metal and metal oxides will allow fabrication of cost efficient and straightforward water splitting devices.