Periodic Reporting for period 2 - PARACAT (Paramagnetic Species in Catalysis Research. A Unified Approach Towards Heterogeneous, Homogeneous and Enzyme Catalysis)
Reporting period: 2021-01-01 to 2023-06-30
Catalysis is recognized as one of the key drivers for wealth-creating industry, including the sustainability of our society. In this context, the EJD-PARACAT project aims to comprehensively explore for the first time the role of open-shell species in catalysis and chemical reactivity, which are notoriously difficult to study by conventional experimental tools. The project provides advanced training and expertise to 10 Early Stage Researchers (ESRs) focusing of how open-shell species participate in catalytic reactions. The objective is to enhance the availability of highly skilled researchers competent in advanced instruments and techniques, using a scientific approach and training protocol that is novel within the EU context. The basic tenet of the PARACAT training programme is that “knowledge ought to precede application”. By recognising and understanding the impact of open-shell species in chemical reactivity and catalysis, the ESRs will be equipped with the skills required to design more efficient catalysts and sustainable processes. The goal is to create a chain of knowledge whereby fundamental understanding is translated into practical applications by the synergic interaction between academic and industrial partners. The programme focuses on the multidisciplinary aspects associated with the role of paramagnetic species in key reactions of paramount importance for sustainable development, with emphasis on small molecule activation, selective oxidation of hydrocarbons and olefin polymerization, using homogeneous, heterogeneous or bio-catalysts. To do so it includes the input of (bio) chemists, (bio) physicists, industrial partners and an ethicist, delivering further emphasis on the ethics and social reflections of their research.
The PARACAT project has thus far made excellent progress towards achieving our project objectives. All 10 ESRs are enrolled in the PhD programmes of their primary host Universities as implemented using 7 bilateral joint doctoral degrees. According to the initial research investigations, no deviations from the original workplan have been made, with only minor alterations to the timing and location of several ESR secondments. These changes have not adversely changed the overall scope or direction of the PARACAT programme in any way. Training activities have closely followed the initial proposal, including network-wide Summer and Winter Schools, which played an important role in establishing the interdisciplinary focus of the network. From the scientific perspective, ESR1 (Research Project Title: “Application of Earth Abundant Metals (EAMs) for small molecule activation and C-C cross coupling”) focused on air-stable earth abundant copper based homogeneous catalysts for C-C coupling and alcohol transformations. ESR2 (Project Title: “Activation of small molecules by cupric ions in MOFs and zeolites”) concentrated on copper exchanged zeolite chabazite as a model system for CO2 and CH4 activation and specific 17O enrichment protocols have been designed allowing for 17O Highe resolution EPR experiments to be performed. The first part of ESR3’s work (Project Title: “Mechanistic insight in peroxidase activity towards industrial applications”) focused on the EPR analysis of chlorite dismutase proteins for industrial applications and initial tests were performed to incorporate CCld in porous titania and silica. ESR4 (Project Title: “Paramagnetic active sites in Ziegler Natta Catalysts”) explored the nature of reduced Ti species on different industrially inorganic supports provided by the industrial partner organisation LYB. ESR5 (Project Title: “The role of Cr paramagnetic states in olefin polymerization over Phillips catalysts”) attempted to synthesize and characterize by EPR spectroscopy a variety of Cr supported catalysts with different Cr loading, including EPR active Cr(V) and Cr(III) species. ESR6 (Project Title: “Elucidation of the role of paramagnetic valence states of chromium, vanadium, and iron in bimetallic MIL-100 and MIL-101 MOF catalysts”) attempted to synthesize and characterize by EPR a variety of bimetal MOFs with containing paramagnetic high spin ions that may serve as model catalysts for olefin polymerization reactions or as precursors for such catalysts. ESR7 (Project Title: “Towards tuning P450 reactivity: Study of the oxidation cycle of CYP116B5 using H2O2”) has started working with oxygenases of the P450 family, the newly discovered CYP116B5 and the closely related CYPBM3. ESR8 (Project Title: “Studying the role of proximal heme ligation in the reactivity of compound I by hyperfine spectroscopy”) has obtained several peroxidases and reproduced reported kinetic experiments of the reaction with hydrogen peroxide. The characterization of the EPR spectrum of the enzyme resting states has also been performed. ESR9 (Project Title: “An EPR investigation of p-xylene oxidation”) kick-started the project using a series of Cr catalysts to determine the nature, distribution and abundance of the free radicals involved in the reaction with ethylene, whereby a series of catalysts were prepared and characterized by CW-EPR. The analysis of the spectra was performed in order to benchmark the signals to closely related structures. Finally, ESR10 (Project Title: “Combined EPR - DFT methodology to gain mechanistic insights in transition-metal catalysed oxidation reactions of organic molecules”) focused on the analysis of the thiosulfonylation of unactivated alkenes with visible-light organic photocatalysis.
Catalysis is the key enabling technology of the current chemical industry, forming the basis for the production of all energy vectors and all chemicals. The PARACAT project is oriented towards future needs in this area, providing opportunities to turn new concepts into innovation and competitiveness. Deepening our knowledge of paramagnetism in catalysis holds the secrets for the development of new catalysts and catalytic processes with considerable scientific, social and economic benefits within the context of sustainable development. From the scientific perspective, PARACAT is creating a new research methodology to characterize and understand open-shell species in catalysis, which can potentially lead to i) the design of new catalysts based on earth abundant metals, ii) the discovery of new and more sustainable reaction pathways for the activation of small molecules and selective oxidations, drawing inspiration from nature, and iii) enabling new routes for polymerization and depolymerisation reactions. Last but not least, the project provides the EU with highly-skilled scientists possessing a strong ethical background, capable of clarifying and managing social and ethical implications of contemporary and future scientific challenges.