Understanding of the Carbon Chain Growth in Electroreduction of Carbon Dioxide to Produce C3+ Molecules.

Electrochemical reduction of carbon dioxide to value-added chemical feedstocks and fuels presents a promising strategy for carbon utilization and storage. Although advancements in enhancing the selectivity for C1 and C2 products have been witnessed, the research progress for efficient production of C3+ molecules remains slow. Moreover, the mechanism underlying carbon chain growth is still ambiguous. In this review, the recent developments in understanding how C-C coupling proceeds in the pathway toward C3+ molecules are mainly focused on. A few examples which reported the formation of C3-C6 molecules in electroreduction of carbon dioxide are first elaborated. Then, the production of 1-propanol, 2-propanol, 1-butanol, allyl alcohol, and propylene, with particular attention to the mechanism of carbon chain growth, is consecutively discussed. Moreover, alternatives for synthesizing valuable C3+ molecules from carbon dioxide, including tandem electrolyzer and electro-bio hybrid systems, are explored. The review is concluded with remarks on current challenges as well as perspectives on future research possibilities in electroreduction of carbon dioxide to C3+ chemicals and fuels.