Cathode Catalyst For Formic Acid Electrolyzer


Cathode catalyst for a water electrolyzer hand painted on nickel fiber paper



A formic acid electrolyzer cathode catalyst.  Dioxide Materials’ cathode catalyst is hand painted on carbon fiber paper.  Each cathode catalyst is custom-made to order.

Dioxide Materials Formic Acid Cell

Dioxide Materials (DM) has developed a novel, innovative technology in electrochemically converting CO2 into a pure formic acid product. The developed Formic Acid (FA) Process only requires CO2, deionized water, and electrical power.

The DM electrochemical formic acid cell configuration is based on a three-compartment cell.  The cell design consists of:

  1. an anode compartment,
  2. a center flow compartment containing a cation exchange media where formic acid is collected and removed from the cell,
  3. and a cathode compartment where the electrochemical reduction of CO2 to formate ions occurs.

Dioxide Materials Sustainion® anion exchange membrane, and related ionomers are key to the formic acid technology.  The electrochemical CO2 reduction reaction, occurring with the catalyst on the cathode, is theorized to be facilitated by the addition of an imidazole-based ionomer incorporated into the cathode catalyst layer. The formation of a CO2-imidazolium complex is proposed to lower the free energy required for the reduction reaction.  The Sustainion® anion exchange membrane at the membrane-cathode catalyst interface may also be involved in the reduction reactions. The Sustainion® anion exchange membrane, and related ionomers  allow the electrochemical process to operate at high current densities and Faradaic efficiencies. This enables a high concentration pure formic acid product in the 5 – 25 wt% range to be produced.