High Indirect Energy Consumption in AEM-Based CO₂Electrolyzers Demonstrates the Potential of Bipolar Membranes

Typically, anion exchange membranes (AEMs) are used in CO2 electrolyzers, but those suffer from unwanted CO2 crossover, implying (indirect) energy consumption for generating an excess of CO2 feed and purification of the KOH anolyte. As an alternative, bipolar membranes (BPMs) have been suggested, which mitigate the reactant loss by...

Orientation of a bipolar membrane determines the dominant ion and carbonic species transport in membrane electrode assemblies for CO₂reduction

A bipolar membrane (BPM), consisting of a cation and an anion exchange layer (CEL and AEL), can be used in an electrochemical cell in two orientations: reverse bias and forward bias. A reverse bias is traditionally used to facilitate water dissociation and control the pH at either side. A forward bias has been proposed for several...

Reduced Ion Crossover in Bipolar Membrane Electrolysis via Increased Current Density, Molecular Size, and Valence

A bipolar membrane (BPM) can be used to accelerate water dissociation to maintain a pH gradient in electrochemical cells, providing freedom to independently optimize the environments and catalysts used for paired reduction and oxidation reactions. The two physical layers in a BPM, respectively, selective for the exchange of cations and anions...

Electrochemical impedance spectroscopy as a performance indicator of water dissociation in bipolar membranes

A bipolar membrane (BPM) can be used to maintain a pH difference in an electrolysis cell, which provides freedom to independently optimize the environments and catalysts used for paired redox reactions. A BPM consists of two physical layers, of which one is selective for the exchange of cations and the other for anions. The water dissociation...