Converting CO₂ Directly into Fuels and Chemicals
TU Berlin Launches Two Research Projects on Direct Electrochemical CO₂ Conversion—Without the Detour via Hydrogen
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In the future, carbon dioxide should not only be avoided or captured, but also used as a raw material: Researchers at the Technical University of Berlin are working on processes that use electricity to directly convert CO₂ into chemical feedstocks and building blocks for synthetic fuels. Over the next three years, two new research projects will address different challenges in this area: While JEThylen is further developing the direct electrochemical conversion of CO₂ into ethylene as a feedstock for synthetic jet fuel, INNOCELL is working on more efficient and scalable electrolytic cells for CO₂ conversion. The Department of Technical electrochemistry and Electrocatalysis at TU Berlin will receive a total of approximately 2.6 million euros for both projects.
In many processes for producing synthetic fuels, water is first split into green hydrogen and oxygen using renewable electricity from solar, wind, and hydro power. The hydrogen is then used, together with CO₂, to synthesize feedstocks and intermediates for the chemical fuel industry. Researchers at TU Berlin are pursuing a different approach: In direct CO₂ electrolysis, carbon dioxide is reacted directly with water in an electrochemical cell. This process can immediately produce chemical fuel precursors—without first having to produce and store hydrogen as a standalone energy carrier. “Our key reactions for this are already underway in the lab,” says Prof. Dr. Peter Strasser, head of the Technical Electrochemistry and Electrocatalysis Division. “The challenge now is to make the electrolysers more efficient, more durable, and larger.”
Ethylene as a Feedstock for Synthetic Aviation Fuel
The JEThylen project is dedicated to the direct electrochemical conversion of CO₂ into ethylene. Ethylene is an important raw material in the chemical industry and can serve as a starting material for the production of synthetic jet fuel. In a downstream process, it is first converted into longer hydrocarbons and then further processed. The advantage of this process is that the direct electrochemical reaction of carbon dioxide and the subsequent chemical processing of ethylene result in a comparatively short process chain at relatively low temperatures. This increases energy efficiency.
The project is coordinated by Siemens Energy as the consortium leader. Other partner institutions include the Technical University of Berlin (TU Berlin), the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), and the aviation think tank Bauhaus Luftfahrt. Together, they aim to make direct CO₂ electrolysis to produce ethylene more efficient, more durable, and suitable for larger-scale plants. To achieve this, they plan to reduce the cell voltage from the current level of about 4.5 volts to around 2.5 volts. “Through these and other measures, we aim to increase energy efficiency from the current level of about 27 percent to 50 percent. At the same time, we are striving for stable operation for at least 1,000 hours,” says Strasser. In terms of size, too, this represents a significant step forward: While comparable laboratory systems have typically operated with electrode areas of about 10 square centimeters, the technical facility is designed to enable the operation of cells in the range of several hundred cm², and, building on this, concepts for industrial scaling to electrode areas of up to 0.5 square meters—that is, 5,000 square centimeters—will be developed. JEThylen is funded by the Federal Ministry of Research, Technology, and Space (BMFTR) as part of the DISCO₂ funding initiative (“Disruptive Approaches to the Industrial Use of CO₂”). The project runs from March 2026 to February 2029, with TU Berlin receiving approximately one million euros in funding.
New Cells for CO₂ Electrolysis
The second project, INNOCELL, addresses a different challenge: How can electrolytic cells generally be designed to operate efficiently and stably even on a larger scale? The starting point is a cell design for so-called gas diffusion electrodes developed and patented at TU Berlin. These electrodes make it possible to feed gaseous CO₂ directly to the catalyst, thereby achieving high current densities. The project utilizes water-repellent, electrically insulating polymer substrates. They help ensure that the gas diffusion electrodes are less prone to flooding with electrolyte. This problem, known as “flooding,” causes the pores in the gas diffusion electrodes to become clogged, thereby severely hindering the process. With the help of the water-repellent polymer substrates, the cells can operate stably even at high current densities. A specially developed current collector is used to establish the necessary electrical contact.
Production not only of ethylene, but also of carbon monoxide and other hydrocarbons
The cells are tested at temperatures ranging from 60 to 80 degrees Celsius and at pressures of up to 30 bar—conditions relevant to industrial applications of CO₂ electrolyzers. The project aims to achieve current densities of at least 500 milliamps per square centimeter, an energy efficiency of at least 45 percent, and an operating life of at least 1,000 hours. The operation of the cells is not limited to the electrolysis of ethylene: INNOCELL is also investigating the production of carbon monoxide (CO). CO is an important intermediate product in the chemical industry and a component of synthesis gas, from which methanol and other synthetic fuels, among other things, are produced. “Which application will be pursued on a larger scale will be determined within the project based on the performance values achieved,” explains Peter Strasser.
The project will run from 2026 to 2029 as part of the “VIP+” program of the Federal Ministry of Education and Research. This program evaluates and further develops research results with potential for economic or societal applications to assess their feasibility. The grant amount for TU Berlin is 1.6 million euros.
Note: This article has been translated using a computer system without human intervention. LUMITOS offers these automatic translations to present a wider range of current news. Since this article has been translated with automatic translation, it is possible that it contains errors in vocabulary, syntax or grammar. The original article in German can be found here.
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