Carbon Dioxide Valorization
Carbon dioxide from the combustion of fossil sources is regarded as the most significant greenhouse gas; hence, CO2 capture and conversion has attracted considerable attention in the past years. As an abundant, nontoxic, non-flammable and renewable carbon resource, CO2 is attractive as a feedstock for making fine chemicals and materials.
CARBOFLOW: Streamlined CO2 conversion– a platform strategy for modern carbonylation chemistry
Since the discovery in the nineteenth century, carbonylation chemistry has found broad applicability in chemical industries and become now a key technology for bulk and fine chemical synthesis. Despite its substantial toxicity, carbon monoxide (CO) is commonly used as carbonyl source causing considerable safety issues, particularly when transported and used on bulk scale. The replacement of this hazardous gas with more benign surrogates would be highly desirable, and recent ideas focus on the valorization of carbon dioxide as abundant, non-toxic and renewable carbon resource. However, few industrial processes utilize carbon dioxide as a raw material, and potent catalysts are required to overcome its thermodynamic and kinetic barrier. In this regard, ionic liquids show considerable potential as cooperative media as they can solubilize large concentrations of carbon dioxide but also strongly interact and activate carbon dioxide.
The ERC-funded project CARBOFLOW focuses on the photocatalytic reduction of carbon dioxide in ionic liquids and its successive conversion into carbonyl compounds. Several goals need to be realized, including fundamental studies and optimization of the ionic liquid co-catalysed photocatalytic reduction of carbon dioxide to produce CO under mild conditions. The reactivity of formed CO in supercritical carbon dioxide with various organic substrates needs to be explored before finally developing a streamlined and continuous process for the direct formation of carbonyl compounds from carbon dioxide.
We envision that the photocatalytic activation of carbon dioxide in combination with the positive features of tailored ionic liquids as co-catalysts may overcome problems currently associated with carbon dioxide utilization, eventually replacing the long-standing bastion of CO-based carbonylation chemistry with novel solutions.
Representing publications:
A. Sainz Martinez, C. et al. Continuous conversion of carbon dioxide to propylene carbonate with supported ionic liquids, ACS Sus. Chem. Eng. 2018, 6, 13131.