U.S. Patent No. 10,428,432 Catalyst Layer and Electrolyzers issued to Dioxide Materials

The recent development and market introduction of a new type of alkaline stable anion membrane and related ionomers used by Dioxide Materials is enabling the advancement of new and improved electrochemical processes which can operate at commercially viable operating voltages, current efficiencies, and current densities

Dioxide Materials’ latest patent, U.S. Patent No. 10,428,432, claims the use of a catalyst layer for an electrochemical device that comprises a catalytically active element and an ion conducting polymer that includes positively charged cyclic amine groups and polymers or copolymers of styrene.  We had previously shown that ionic liquids containing cyclic amines can be used to enhance electron transfer in CO₂ and water electrolyzers thus lowering the overpotential for CO₂ and alkaline water electrolysis.  This patent shows that polymers or copolymers of styrene and cyclic amine groups can pave the way to more cost-effective routes to sustainable chemicals and fuels production.  

Initially, this new polymer was developed for CO₂ electrolysis, but we found that it also improved current densities at low voltage in anion exchange membrane alkaline electrolyzers. Having an alkaline environment enables the use of non-precious metals and saves cost by eliminating to use of platinum and iridium catalysts since the oxygen reduction is more easily catalyzed. Our alkaline stable Sustainion® membrane has enabled the development of zero-gap design electrolyzers. 

The team at Dioxide Materials has found that polymers are much easier to work with than ionic liquids.  They stay put so you do not need a supporting electrolyte. Instead, you can reuse them multiple times.  The CO2 electrolyzers have run at  200 mA/cm2 (3v) at room temperature  for 6 months with no obvious degradation. The alkaline water electrolyzers have run at (1 M KOH, 60 C) at 1 A/cm2 for over a year with no obvious degradation.

More information on research grade electrolyzers, Sustainion membranes and ionomers, as well as electrodes and cell components can be found at www.dioxidematerials.com.