Catalytic carbon dioxide recycling to chemical products in fuel cells

There are various attempts to save carbon dioxide emissions by carbon collection and storage (CCS) or carbon collection and utilization (CCU). The electrochemical methods for CCU are extensively studied. They are classified in two classes: electrolysis with chemical production and fuel cell applications. The electro-catalytic electrolysis is associated with additional energy input and there is subsequent discharge of carbon dioxide in the atmosphere. That is why the fuel cell applications are preferable, because of the multiple benefits: carbon dioxide saving, useful chemical products formation and carbon-free energy production.
In the present study the performance of fuel cell driven by bicarbonate/carbonate solution is tested. Wastewater of high chemical oxygen demand (COD) as a fuel was used. Different catalysts containing manganese, tin, platinum and rhodium, embedded into activated carbon matrices were used. Chemical products of carbonate reduction were detected: formic acid, methanol, as well as some olefins and aromatic compounds. Best results were obtained by tin-doped activated carbon as catalyst.
Acknowledgment: The work was supported by grant KP-06-N27/1/2018 of the Fund for Scientific Research and by the program HITMOBIL by the Ministry of Education and Science, Republic of Bulgaria.