Nowadays, crude oil and natural gas are the main sources for the production of fuels and feedstock chemicals. These resources are limited and mankind urgently needs alternatives for a more sustainable production of chemicals from renewable feedstock (e.g. wood biomass). This is why I decided to join the search for novel porous nano-materials such as zeolites.
Izabela Czekaj
Zeolites are minerals and chemical compounds within the group of silicates. Thanks to their specific crystalline structure, zeolites have water-binding capacities and can act like a mineral sponge or sieve. Zeolites have been successfully used as catalysts to facilitate many chemical reactions, but their properties can be improved with a better understanding of their molecular structure and complexity of active centres. The main goal of the project was to design – at nano-scale – zeolites with enhanced catalytic performance, optimized for biomass transformation to dedicated chemicals. The research was focused on zeolites with different pore sizes. Zeolites are available commercially in purely microporous form but for the purposes of our experiments we also synthesized zeolites in mesoporous shape and with the addition of selected metals. The structure of zeolites is very complicated; therefore, realistic three dimensional models of their crystallographic structure were also designed. The project used new insights from both molecular modelling and experimental methods to obtain knowledge about zeolite topology and catalytic properties.
The integration of both paths, experimental and theoretical, in the same research team was a novel approach. It guaranteed rapid progress in new catalysts and processes development in the very difficult subject of wood biomass catalytic transformation as well as exceptional training for students on the subject of nano-design of zeolite-based catalysts for selective conversion of biomass into chemicals.
The team designed experiments to study the development of catalytic routes for the conversion of bio-renewable feedstocks to selected key chemicals: acrylic acid and its derivatives used for the preparation of a variety of materials such as fabrics, paints, varnishes, adhesives, acrylic rubbers, detergents or water-absorbent polymers used in diapers. Examination of the effect of the zeolites as support for the nanostructure and reactivity of the metal nanoparticles was carried out in detail. We designed modifications of zeolite which could be used in the process of biomass (wood and corn waste) conversion reactions into valuable chemicals. The processes have been successfully tested in different phases, including in the gaseous liquid phase, which is important in industrial applications. Such processes were not possible without such effective catalysts as modified zeolites. Additionally, we found out that a clinoptilolite – a natural and inexpensive zeolite – can also be successfully used for biomass conversion reaction, which is important for economic reasons.
We used a density functional theory method to explore active sites and the electronic structure of zeolite catalysts during reactions, which led us to the development of a new class of catalysts with a declared molecular structure. We also performed theoretical modelling of different components derived from wood biomass (lignin dimers, selected sugars from cellulose and hemicellulose), which allowed us to obtain a theoretical Vibrations Basis Database for experimental spectra interpretation.
A number of uncertainties still remain in relation to biomass transformation into valuable chemicals. One such problem is the production of a large number of by-products. Another is the existence of many phases during these processes, which makes them very difficult to apply at an industrial scale. Solving these problems would have a significant impact on the development of science and the economy of zeolite catalysts as well as on the environmentally friendly production of important chemicals.
How did you benefit from the POLONEZ fellowship?
The POLONEZ grant gave me an exceptional perspective to return to academic work after a maternity break at the previous level as well as a move to a university in Poland after ten years of working and living in Switzerland. I was able to develop new skills (e.g. catalyst synthesis and nanoarchitecture, a new modelling approach, business contacts in Poland, negotiations skills), which gave me new perspectives to create the independent research group that I now direct. The Catalytic and Nanostructured Materials Design Group was officially established in 2017. Theoretical modelling combined with experimental knowledge gave me the opportunity to create databases that are actually used to explain many complex catalytic reactions, which constitute a basis for obtaining a virtual image of more efficient industrial catalysts. The fellowship helped me to increase my pedagogical skills and leadership abilities.
Dr hab. Eng. Izabela Czekaj prof. PK obtained a Master’s degree in engineering in 1999 at the Faculty of Technology and Chemical Engineering, Cracow University of Technology (CUT). She defended her doctoral thesis in the field of heterogeneous catalysis and theoretical modelling in 2004 under the supervision of Prof. Małgorzata Witko. Between 2005 and 2015 she worked in the Paul Scherrer Institute and Institute of Chemistry and Biochemistry Eidgenössische Technische Hochschule Zürich, continuing her interests in heterogeneous catalysis, theoretical modelling and modern spectroscopy. Since 2015 she has led the independent research group ‘Catalytic and Nanostructured Materials Design’ in the Institute of Organic Chemistry and Technology at CUT, working on a variety of subjects including the design of materials and processes of biomass valorisation, deodorization, deNOx, electro- and photochemistry.
