Anion exchange polymers having high OH.sup.− conductivity, chemical stability, and mechanical stability have been developed for use in AEMs. The anion exchange polymers have stable hydrophobic polymer backbones, stable hydrophilic quaternary ammonium cationic groups, and hydrophilic phenolic hydroxyl groups on the polymer side chains. The polymers have polymer backbones free of ether bonds, hydrophilic polymer side chains, and piperidinium ion-conducting functionality, which enables efficient and stable operation in water or CO.sub.2 electrolysis, redox flow battery, and fuel cell applications. The polymer comprises a plurality of repeating units of formula (I)

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Anion exchange membranes and membrane electrode assemblies incorporating the anion exchange polymers are also described.

A supported catalyst for reducing CO.sub.2 is provided. The supported catalyst includes a plurality of support particles; and a plurality of catalyst particles disposed over each support particle. Characteristically, the catalyst particles has formula PdH.sub.x/C wherein x is 0.3 to 0.7. Methods for making the support particles and using the support particles to reduce carbon dioxide are also provided.

The invention provides a diaphragm for alkaline water electrolysis with reduced dissolution of an inorganic component in an alkali solution at low cost. The present invention relates to a diaphragm for alkaline water electrolysis, including magnesium hydroxide and an organic polymer resin.

The invention provides a diaphragm for alkaline water electrolysis with reduced dissolution of an inorganic component in an alkali solution at low cost. The present invention relates to a diaphragm for alkaline water electrolysis, including magnesium hydroxide and an organic polymer resin.

This invention relates to a device for the electrolytic production of hydrogen and oxygen from a water-containing liquid, the device comprising: an anodic half-cell (3) and a cathodic half-cell (4), with an anion exchange membrane (9) situated between the two half-cells. The electrodes (7, 8) of the half-cells (3, 4) and the anion exchange membrane (9) form a membrane/electrode assembly (MEA). There is also provided means (2) for feeding the water-containing liquid to only one of the anodic half-cell (3) and the cathodic half-cell (4), wherein the electrode in the other, substantially dry, half-cell is ionomer-free and/or binder-free.

This invention relates to a device for the electrolytic production of hydrogen and oxygen from a water-containing liquid, the device comprising: an anodic half-cell (3) and a cathodic half-cell (4), with an anion exchange membrane (9) situated between the two half-cells. The electrodes (7, 8) of the half-cells (3, 4) and the anion exchange membrane (9) form a membrane/electrode assembly (MEA). There is also provided means (2) for feeding the water-containing liquid to only one of the anodic half-cell (3) and the cathodic half-cell (4), wherein the electrode in the other, substantially dry, half-cell is ionomer-free and/or binder-free.

In an aspect, a hydrogen separation unit includes an electrochemical cell stack that includes a separator stack located in between an anode side and a cathode side; a mixed gas conduit for receiving a mixed gas stream to the anode side; an anode removal conduit for removing a helium rich stream from the anode side; and a cathode removal conduit for removing a hydrogen rich stream from the cathode side. The separation stack includes a plurality of electrochemical cells, each of which includes a proton exchange membrane located in between an anode and a cathode. The proton exchange membrane can include a cation. The separation stack can be a cascading separation stack.

A method for operating a wastewater treatment system is disclosed wherein the wastewater treatment system comprises at least one electrochemical cell comprising dimensionally stable electrodes having the same catalyst composition, the electrodes being immersed in wastewater and being connected to a power supply and wherein the voltage at the power supply is monitored and the polarity of the electrochemical cell(s) is reversed when the recorded voltage increases by a predetermined voltage difference. The wastewater treatment system can comprise at least one electrochemical cell which is kept inactive while the active electrochemical cells are operating. The inactive cell(s) can be activated when all the electrodes of the active cells are consumed as indicated by another increase in voltage at the power supply after the polarity of the active cells has been once reversed.

A method for operating a wastewater treatment system is disclosed wherein the wastewater treatment system comprises at least one electrochemical cell comprising dimensionally stable electrodes having the same catalyst composition, the electrodes being immersed in wastewater and being connected to a power supply and wherein the voltage at the power supply is monitored and the polarity of the electrochemical cell(s) is reversed when the recorded voltage increases by a predetermined voltage difference. The wastewater treatment system can comprise at least one electrochemical cell which is kept inactive while the active electrochemical cells are operating. The inactive cell(s) can be activated when all the electrodes of the active cells are consumed as indicated by another increase in voltage at the power supply after the polarity of the active cells has been once reversed.

An electrode structure for a positive electrode of a metal-air battery is provided. The electrode structure for a positive electrode of a metal-air battery is formed of a compound of copper, phosphorus, and sulfur and it can comprise a membrane in which a plurality of fibrillated fibers form a network.