Electrochemical reduction of carbon dioxide to useful chemical intermediates

The rise of carbon dioxide (CO2) emissions from a range of power plants and industrial sources have contributed to alarmingly-increased atmospheric levels of CO2. Several capture and sequestration (CCS) technologies are under investigation to reduce CO2 emissions from new and existing coal- and gas-fired power plants and large industrial sources. Although there are a number of active and effective CCS programs, there remains a strong need for alternative routes to recycle the CO2 into useful products rather than just sequestering the CO2 for long-term storage. This will provide new valuable products and drive a market for the CO2 to offset the capture costs. The direct use of the CO2 as a chemical feedstock represents a logical strategy. However, due to the high thermodynamic stability of CO2, conventional chemical synthesis routes require high activation temperatures and pressures to drive the reaction, thus limiting the economic viability of the direct use of CO2.Statement of how this problem or situation is being addressed Electrochemical activation provides an alternative low temperature and pressure route with much lower energy pathway, thus facilitating direct reuse of CO2. Furthermore, the potential synthesis of carboxylic acids by the direct insertion of the electrochemically activated CO2 radical represents a cost-effective pathway to an interesting and attractive class of chemicals. Carboxylic acids are used as key intermediates in a wide range of pharmaceuticals, polymers, agrochemicals, and fragrances, with a large number of both high-volume and niche high-value products possible. In Phase I, Mainstream demonstrated the stable production of a range of carboxylic acid intermediates with high yields and current efficiencies using Mainstream’s high-performance gas diffusion based electrode structures and electrochemical flow cell design. The direct electrochemical insertion of CO2 not only provides a pathway to utilizing abundant CO2 but offers an alternative more straightforward and more environmentally acceptable route to many carboxylic acids. In Phase II, we will further optimize the gas diffusion electrode, electrochemical cells design and overall reaction chemistry to maximize the yield, reaction rate and overall energy efficiency for the capture and reuse of CO2.Commercial Applications and Other BenefitsMainstream’s electrochemical synthesis can be applied to utilize CO2 directly in a wide range of chemical syntheses of valuable organic intermediates. Our approach provides a low energy pathway to the utilization of the abundant supply of captured CO2 provide a market for the CO2 as well as providing an economically and environmentally viable approach to the production of in-demand chemical intermediates.