Periodic Reporting for period 2 - PIONEER (Plasma catalysis for CO2 recycling and green chemistry)
Reporting period: 2021-01-01 to 2022-12-31
Converting CO2 is essential not only to limit release into the atmosphere and the oceans, but also to be able to store and transport the energy produced by renewable energy sources (wind, solar, etc...). Cold plasmas are weakly ionised gases in which a small proportion of highly energetic electrons make it possible to initiate chemical reactions without heating the gas, and at minimal energy cost. New catalytic materials have to be invented to make the most of the reactive species produced by the plasma and to control the selectivity of the reaction products formed. Thus, with the innovative plasma/catalysis coupling systems studied by the PIONEER ESRs, CO2 can be converted either with hydrogen (H2) to form methane (CH4), or to make synthetic fuels by combining CO2 and CH4 to form ethanol and methanol. The 14 doctoral projects of the PIONEER ESRs are all interconnected and study both very fundamental aspects of the complex interaction between plasma and surfaces, as well as innovative reactor designs aimed at better conversion rate performance and energy efficiency.
From a fundamental point of view, new in situ and time-resolved measurement methods have been implemented both to characterise the radicals produced in the plasma (laser-induced fluorescence, fast infrared absorption, etc...) and the surface properties of catalytic materials directly exposed to the plasma (infrared absorption in transmission, electric field measurement by polarimetry, etc.).
These measurement methods are state of the art techniques and allow for the first time direct access to interaction phenomena at the interface of a plasma and a complex surface. New materials with singular properties have also been developed such as zeolites promoted with Ru or Ni, Double Layered mixed oxides impregnated with Ni or Ceria based materials.
Finally, novel plasma/catalyst coupling strategies such as plasma fluidised beds or plasma in liquid solvents in the presence of catalyst powders in suspension.
Thus each work provide novelty listed here in order to bring new understanding in plasma catalysis systems and new tools for developping CO2 plasma catalysis technologies in larger scale. Thus in the field of Electric fields on catalyst covered dielectric surfaces under plasma exposure. All these results are important, novel and bring new undertanding and tools for developping the proposed technology. More than 20 publications are published or under submission, More than 10 international conferences were attende by the ESR which show the huge work developed in this project and that the 14 ESR involved untill the end are now new specialists in these novel Plasma Catalytic CO2 technology for CO2 abatment
PIONEER is also a place for the transmission of knowledge, obviously for the training of ESRs, but also for the scientific community and the general public. Tools such as a database of plasma/catalysis coupling performance is being built, as well as a standardised reactor to improve the relevance of comparisons of work carried out in various laboratories even beyond PIONEER consortium itself. A website and regular communications on Twitter, Instagram, and LinkedIn allow a wide dissemination of PIONEER's activities. In addition, the results are shared with the scientific community by taking part in conferences and publications.The Pioneer project is well launched and to date the expected results are encouraging, the ESRs are being followed the hoped-for trainings and the research is ongoing. As reported 3 WP are linked with results and potential impacts. The WP2 Fundamentals & Mechanisms addresses fundamental knowledge of the interaction between plasma and catalyst. This knowledge are crucial to know the constraints of the design of catalyst appropriate for CO2 plasmolysis. The WP 3 was dedicated to Advanced Catalysts for CO2 conversion under plasma exposure.
New catalysts were proposed and tested in BDB plasma for methane and methanol production, a coupling with modeling was also performed. Also, ultra pulsed plasma was used for methane reforming leading to syngas production. Finally the WP4 deled with Innovative routes for plasma/catalyst coupling. Here, the project has light on the transient conditions present both in-pulse as well as intra-pulse, where it has been shown that by tailoring the power pulsing scheme a highly perturbed environment is created that is conductive to CO2 dissociation, significantly reducing energy input, whereas it was shown also that Optimizing air plasma reactor requires detailed understanding of the reactor temperature and the impact pressure has upon the plasma parameters. In addition, it was shown that Investigating methods to vibrationally excite CO2 with plasma has the potential to facilitate the development of more sophisticated plasma chemistry models as it provides the fundamental cross section data as well as experimental data to validate the simulations. The Plasma-catalytic CO2 conversion in liquid water was studied for the first time in this project. The results show a significant change in paradigm in the field, since water is usually regarded as detrimental to the reactions of interest but it proved to be an interesting pathway to long-chain organic liquids, when used in liquid-phase. Furthermore, it was also observed that, to some extent, MnO was converted into MnCO3, and the conversion of oxides into carbonates is also a suitable strategy to fixate CO2, but still rather unexplored using plasma. Finally, the work developed in Pioneer carried out by complements fundamental studies in only CO2 and CO2-CH4 plasmas interacting with catalytic materials.