Carbon dioxide from the combustion of fossil sources is regarded as the most significant greenhouse gas; hence, carbon dioxide capture and utilization (CCU) has attracted considerable attention in the past years. As an abundant, nontoxic, non-flammable and renewable carbon resource, carbon dioxide is attractive as a feedstock for making fine chemicals and materials. Since the discovery in the nineteenth century, carbonylation chemistry has found broad applicability in chemical industries and become now 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.
The ERC-funded project CARBOFLOW focuses on the photocatalytic reduction of carbon dioxide in ionic liquids and its successive conversion into high value 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 as building block under mild conditions. The reactivity of formed CO in 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.
Overall, we expect that the photocatalytic activation of carbon dioxide may overcome problems currently associated with carbon dioxide utilization, eventually replacing the long-standing bastion of CO-based carbonylation chemistry with novel solutions.