The project investigated the feasibility of using CO₂ as a feedstock for the synthesis of key organic intermediates, focusing on the direct conversion of CO₂ to short‑chain olefins. At the core of the work was the development and detailed characterization of a series of catalysts, including a Cu/ZnO/Al₂O₃ methanol synthesis catalyst (CZA) and several Zn‑ and In‑based systems. The CZA catalyst was benchmarked against an industrial reference catalyst to assess its suitability for a one‑step olefin synthesis route. Methanol productivity tests were carried out in a custom high‑pressure reactor system that could operate up to 50 bar and accommodate catalyst loads ranging from 0.1 g to 20 g. The setup comprised a small module for rapid mechanistic studies and a larger module for long‑term performance evaluation. Both modules were connected to a French partner‑designed oil‑heated multi‑channel reactor, allowing parallel experiments under identical conditions. A vaporizer unit enabled the introduction of liquid methanol and water into the gas phase, thereby facilitating studies of the methanol‑to‑olefin (MTO) process over zeolite systems. A pulse unit supplied probe molecules for kinetic investigations, and the analytical suite included a gas chromatograph, a Fourier‑transform infrared spectrometer, and a mass spectrometer for high‑time‑resolution transient measurements.

Methanol productivity measurements revealed that the Cu‑based catalyst achieved the highest rates under conventional conditions (250–300 °C) and closely followed the thermodynamic equilibrium curve above 300 °C. In contrast, the oxidation catalysts reached their productivity maxima only above 300 °C and displayed higher activity in CO‑free synthesis gas. Their methanol production exceeded the equilibrium curve, which was defined for the Cu‑catalyst network. These findings indicated that the Cu catalyst is best suited for the temperature window required for olefin synthesis (300–400 °C), while the oxidation catalysts may be advantageous in CO‑free environments.

The project also explored zeolite‑based MTO catalysts. ZSM‑5 P25 outperformed the benchmark SAPO‑34, delivering higher methanol conversion, slower deactivation, and a greater olefin production rate. Temperature‑dependent studies showed that operating at 400 °C increased olefin concentration fourfold compared to lower temperatures, where rapid deactivation due to coking occurred. Long‑term tests at constant 400 °C confirmed the superior stability of ZSM‑5 P25. A two‑stage process was evaluated, with a ZnZr catalyst in the first reactor for methanol synthesis and a zeolite in the second reactor for olefin production. Under conditions of 23 % CO₂, 69 % H₂, 8 % Ar, 500 Nml min⁻¹, and 30 bar, the system achieved stable olefin yields, and regeneration with synthetic air at 400 °C and 1 bar restored activity.

Collaboration was central to the project. The German MPI CEC conducted the CO₂ source qualification, catalyst development, and reactor testing, while a French partner supplied the oil‑heated reactor and contributed to the design of the high‑pressure test rig. The partners coordinated the experimental campaign, data analysis, and interpretation of results, enabling the identification of optimal gas purification steps and process simulation strategies for methanol and olefin synthesis from site‑specific CO₂ streams. The work was carried out over the duration of the project, with results disseminated through joint publications and conference presentations.