Bipolar Electrodes With Gas-Transporting Layers

Stanford researchers have developed a cost effective replacement for bipolar membrane (BPM) electrodialysis, called bipolar electrode (BPE) that more efficiently splits water into separate streams of protons and hydroxide ions.

The use of acid and base reagents in industrial chemical processes often leads to the production of large amounts of salt by-products. Instead of treating the salt as waste, electrochemical technology can be employed to regenerate acid and base from the salt and water. However, the current state-of-the-art technology, bipolar membrane (BPM) electrodialysis, is neither efficient nor durable for splitting water into protons and hydroxide ions.

To address this issue, Stanford researchers invented the bipolar electrode (BPE) comprised of two catalyst layers surrounding a gas-transporting layer. One catalyst generates a gaseous product (e.g., hydrogen) that is transported to the other layer for oxidation, resulting in separate streams of protons and hydroxide ions. The BPE's performance scalability depends on thermodynamic potentials and electrocatalyst effectiveness, and its design prevents parasitic ion crossover, eliminating the need for ion-exchange membranes, presenting significant advantages over BPMs.

Stage of Development - Prototype