Reduzierung der Treibhausgasemissionen und Begrenzung der Erderwärmung auf deutlich unter 2 °C sind die großen Ziele des Pariser Klimaschutzabkommens. Die technische Realisierung dieser Ziele stellt viele emissionsreiche Industriesparten weiterhin vor große Herausforderungen. Ein vielversprechender Ansatz ist der synergetische Verbund von Großindustrien in cross‐industriellen Netzwerken. Mit Carbon2Chem® ist erstmals der Zusammenschluss der Sparten Stahl, Chemie und Energie gelungen. Ziel der Initiative ist es, Hüttengase aus der Stahlproduktion als Ausgangsstoff für chemische Produkte zu nutzen.

Polymer electrolyte membrane water electrolysis cells were studied using in-operando neutron radiography, revealing insights into the gas-water distribution inside the cells. Cells were operated at current densities up to 2 A/cm² and for water flow rates ranging from 0.5 ml/(min cm²) up to 5 ml/(min cm²). The averaged gas amount in the flow channels was quantified, revealing that the ratio of gas to water inside the channels decreases for an increasing water flow rate on the anode side. This examination also demonstrates that neutron radiography is very suitable to study gas/water two-phase flow phenomena in running electrolysis cells.

The present study focuses on structural and dynamical properties of the catalytic layer for high‐temperature polymer electrolyte fuel cells (HT‐PEFC). The catalytic layer is a composite material containing nanoporous carbon, poly(tetrafluoroethylene) (PTFE) and platinum (Pt) nanoparticles. The structure of the catalyst is investigated using small angle X‐ray scattering (SAXS) following different preparation steps of the electrodes: pure carbon support, platinum/carbon (Pt/C) powder and finally, complete catalytic layer. The structural properties of the Pt/C powder containing different amounts of Pt are discussed along with the size distribution of Pt particles and their arrangement on the surface of the carbon support. Following the preparation sequence of the catalytic layer based on the Pt/C powders the electrodes with different final Pt loadings are analyzed in details. Investigation of the structure of the catalytic layer is accompanied by the study of nanosecond dynamics of the phosphoric acid (PA) in the catalytic layer containing different amount of Pt by means of neutron backscattering spectroscopy. The structure of the catalytic layer is mostly determined by the structure of the catalytic powder and does not vary significantly with Pt loading in the electrode. The behavior of the PA is sensitive to the Pt content in the electrode.

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The performance of fuel cells depends largely on the proton diffusion in the proton conducting membrane, the core of a fuel cell. High temperature polymer electrolyte fuel cells are based on a polymer membrane swollen with phosphoric acid as the electrolyte, where proton conduction takes place. We studied the proton diffusion in such membranes with neutron scattering techniques which are especially sensitive to the proton contribution. Time of flight spectroscopy and backscattering spectroscopy have been combined to cover a broad dynamic range. In order to selectively observe the diffusion of protons potentially contributing to the ion conductivity, two samples were prepared, where in one of the samples the phosphoric acid was used with hydrogen replaced by deuterium. The scattering data from the two samples were subtracted in a suitable way after measurement. Thereby subdiffusive behavior of the proton diffusion has been observed and interpreted in terms of a model of fractal diffusion. For this purpose, a scattering function for fractal diffusion has been developed. The fractal diffusion dimension d and the Hausdorff dimension d have been determined on the length scales covered in the neutron scattering experiments.

The aim of Carbon2Chem® is to use CO2‐containing top gases from the steel production as a raw material for chemical products. The scientific foundations and tests with synthetic top gases on a laboratory scale have already been investigated. The technical implementation under real top gas conditions is tested in a technical center that was especially built for the project. In the demonstration plants which are directly connected to the integrated steelwork in Duisburg technologies for CO2 reduction are further developed.

With respect to the climate goals of the greenhouse gas (GHG) neutrality in 2050, different GHG reduction strategies are discussed for industrial processes. For a comparison of the strategies carbon direct avoidance (CDA), carbon capture and storage, and carbon capture and utilization (CCU), the method system expansion is applied. Exemplarily, the CO2 reduction potential and the energy demand are determined. The Carbon2Chem® project is described as an example of CCU for the steel and chemical production. The direct reduction with H2 represents the CDA strategy for the steel industry.