PhasKat – Phase-pure electrocatalysts and adjustment
of conditions regarding the reduction of CO₂

Hydrocarbon-selective electrocatalysts

The material properties of electrocatalysts used to build the electrodes in electrolyzers determine the product
composition in case of the direct single-step electrochemical reduction of CO₂. In “PhasKat”, a fundamental understanding of copper-based electrocatalysts based on the rare copper mineral paramelaconite (Cu₄O₃) is developed. In the paramelaconite-type crystal structure, monovalent and divalent copper atoms occupy two different crystallographic positions within the lattice. These can be chemically substituted by other catalytic active metals like silver or iron, without changing the three-dimensional structure of the lattice. The objective of the researchers is to establish fundamental design rules on how to accomplish long-term stable, selective, and efficient electrocatalysts.

From electrocatalyst to electrode

In an electrode, the electrocatalyst interacts in different ways with its environment. In case of the gaseous precursor CO₂, the electrodes will be designed porous. An anion conducting binder material will enable the direct coupling to the water-based electrolyte. An electrical planar conductor, like a microporous carbon black layer or a metal mesh, connects the catalyst with the current source. This cathode is interconnected with an anode to form the electrolyzer cell, which converts the climate-hazardous CO₂ into ethylene and ethanol in a single-step reduction reaction. The focus of the development in “PhasKat” will be industrial
viable, long-term stable, and efficient approaches. The participation of two major enterprises will enable a rapid implementation into industrial application.

Cooperation of industry and academia

In “PhasKat”, two institutes of the Forschungszentrum Jülich, two entities of the Evonik AG and Siemens Gas and Power GmbH & Co. KG are working together. The Helmholtz Institute Erlangen-Nuremberg for Renewable Energy (HI-ERN, IEK-11) of the Forschungszentrum Jülich is developing methods for the preparation of the electrodes employing spray-coating to efficiently couple the electrocatalyst and the anion conducting binder material. The Evonik Resource Efficiency GmbH is a manufacturer of chemical catalysts. In the project, Evonik is providing catalysts und is preparing the up-scaling to production scale. The Evonik Creavis GmbH is investigating and synthesizing anion conducting binder materials. Their chemical structure will be adapted to the electrocatalysts in terms of conductivity and wettability.

Siemens Gas and Power GmbH & Co.KG is combining the electrocatalysts and ion-conducting binder to form the cathode for the CO₂ reduction. Subsequently, Siemens will develop tailor-made electrolyzers and their operating parameters. The performance will be evaluated regarding product selectivity, stability, and efficiency. Today hydrogen electrolyzers are already part of the product portfolio of Siemens Gas and Power GmbH & Co. KG.

PhasKat project sheet download