CO₂SimO – Photoelectrochemical CO₂ reduction with simultaneous oxidative raw material production

Carbon dioxide for solar energy storage

In view to climate change and increasing energy demand it is not enough to reduce CO₂ emissions. It is also
necessary to make use of the CO₂ content already existing in our atmosphere. A promising tool for utilizing CO₂ is solar energy and the solar production of valuable fuels and chemicals by so-called photocatalysts. The solar conversion of CO₂ has the advantage of directly producing a storable and transportable energy carrier. The project “CO₂SimO” develops a photoelectrochemical cell (PEC) for the future use of CO₂ as raw material for the solar production of methane and hydrogen peroxide.

A new approach for CO₂ conversion

The project focuses on developing new photocatalysts which can make solar energy usable to drive a chemical
reaction. These new photocatalysts will be transferred into gas diffusion electrodes, which are well known for several decades from fuel cell technology or electrolysis. This new approach allows for longer lifetimes and higher efficiencies of solar CO₂ conversion. The valuable hydrogen peroxide (compared to oxygen, which is a product in other PEC concepts) is promising to make this approach economically feasible. The gas diffusion electrode will convert CO₂ to methane directly in the gaseous phase using solar light. Therefore, solubility of  he starting materials, the products, or the photocatalyst into a liquid medium is not an issue. This unique and new approach is not investigated to date. The combination of CO₂ reduction to methane with water oxidation to hydrogen peroxide has not been studied yet and is promising from an economic viewpoint. The product methane can be used not only as a fuel but also as a resource for any process using oil and natural gas as raw material. Hydrogen peroxide is widely used as a bleaching and disinfection agent and is investigated as a potential energy carrier for fuel cells.

From fundamentals to industrial production

The development of the PEC is realized within this joint research project starting with fundamental research of reaction mechanisms, material optimization, process and system development, as well as sustainability analysis. “CO₂SimO” is a joint cooperation project between two industry partners, two research institutes and two universities. The University of Bayreuth is searching for new photocatalysts, the Leibniz University Hanover is focusing on fundamentals of the chemical processes. TANiOBIS GmbH will prepare the photocatalysts on a larger scale based on the results from the University of Bayreuth. The DECHEMA Research Institute will develop electrodes for the PEC, while neoxid GmbH will realize the final PEC. With a new methanisator developed by neoxid the methane concentration in the gas mixture from the PEC will be enhanced. With the help of lifecycle analysis, the Karlsruhe Institute of Technology will analyze the “CO₂SimO” concept regarding its contribution to sustainable chemical production. The project “CO₂SimO” will contribute to the reduction of greenhouse gas emissions and the dependence on fossil fuels. The two industrial partners aim to produce photocatalysts and photoelectrochemical cells in Goslar and Neuss, respectively.

Interview about CO₂SimO

CO₂SimO project sheet download