Periodic Reporting for period 4 - 3MC (3D Model Catalysts to explore new routes to sustainable fuels)
Berichtszeitraum: 2020-03-01 bis 2020-11-30
In this project we used 3D model catalysts as a novel enabling tool to overcome this problem. Their well-defined nature allowed unprecedented precision in the variation of structural parameters (morphology, spatial distribution) of the individual components, while at the same time they mimic real catalysts closely enough to allow testing under industrially relevant conditions. Using this approach we adressed fundamental questions such as:
* What are the mechanisms (structural, electronic, chemical) by which non-metal promoters influence the functionality of copper-based catalysts?
* Which nanoalloys can be formed, how does their composition influence the surface active sites and catalytic functionality under reaction conditions?
* Which size and interface effects occur, and how can we use them to tune the activity and selectivity towards desired products?
Our 3D model catalysts were assembled from ordered mesoporous silica and carbon support materials and consisted mainly of Cu-based promoted and bimetallic nanoparticles, although also some other bimetallic systems were explored (Co-Ni, Au-Ag, Au-Pd). The combination with high resolution imaging, active site characterization and testing under realistic conditions allowed detailed insight into the role of the different components.
Most important achievements of this project include:
* Insight into how Cu-based catalysts for the formation of CO and H2 into fuels and chemical building blocks such as methanol can have a longer lifetime and work more effectively, and how this is influenced by interface effects (with the support), the sieze of the Cu particles, and small amounts of additive (""promoters"")
* Concrete information on the impact of switching to CO2 as feed for building chemicals and fuels, and how the catalyst can be adjusted to account for that
* First results on copper-based catalysts for electrochemical CO2 reduction, and the importance of a second component (much prominently CuSx and Cu-ZnOx
* fundamental understanding of the behaviour of nano-alloys, also under reaction conditions, and how the atoms of tow different metals will redistribute, and how that affect the efficiency of the catalysts."
Remco Dalebout (PhD2) started with investigating pore-confined bimetallic nanoparticles. Together with Jan Willem the RIjk he also established equipment and protocols that allow to measure the conversion of syngas and CO2 to higher alcohols, fuels and other building blocks. He investigated especially the interplay between promoters and reactant feed (aiming for pure CO2 with renewable H2 as the only feed) and understanding how the catalysts should be tuned to accomodate for this specific feed. With the help of operando experiments at the synchrotron he established for the first time the exact nature of the promoter, MnOx or ZnOx for Cu catalysts under working conditions. Jessi van der HOeven also worked on bimetallic nanoparticles, establishing more fundamental knowledge, such as how with two metal components in one nanoparticle, the atomic distribution changed under working conditions ,and how this could be used to design efficient catalysts. She also contributed to the toolbox of analysis techniques for this type of systems
PhD3, Marisol Tapia Rosales, later succeeded has started 1 October 2016, worked on the electrochemical CO2 reduction using Cu-based catalysts. SHe developed methods to prepare electrode consisting of copper nanoparticles on highly conductive carbon supports, which allowed new fundamental insights. Especially noteworthy were the achievements in understanding electronic tuning by the addition of S to the Cu, and the influence of ZnOx and morphology.
Lastly Peter Ngene (PD1), together with the PI, facilitated the above research, but also participated in related investigations with others to promote renewable energy storage and conversion, such as interesting results also obtained in the field of electrochemical energy storage in batteries.
All outcomes of research have been published (or publication is expected soon, for instance a paper having been accepted in Nature Materials), and results have been actively disseminated also at scientific conferences and in workshops. Furthermore they have led to follow-up projects, for instance supported by an industrial partner to further advance the possibilities of direct conversion of CO2 and renewable hydrogen to sustainable fuels and building blocks.