Researchers have invented a new electrode that captures carbon dioxide from exhaust gases and converts it into formic acid in a single step. This device operates effectively with unpurified gases, including those at atmospheric levels, offering a practical approach to reducing pollution. The breakthrough, detailed in ACS Energy Letters, outperforms existing technologies under realistic conditions.
Exhaust from furnaces, fireplaces, and industrial sites releases carbon dioxide, a key pollutant. To tackle this, a team led by Wonyong Choi has engineered an innovative electrode that integrates CO2 capture and conversion. Unlike traditional systems requiring purified CO2, this device handles mixed gases directly, transforming the captured CO2 into formic acid—a chemical valuable for fuel cells and manufacturing.
The electrode consists of three layers: a CO2-capturing material, a gas-permeable carbon paper sheet, and a tin(IV) oxide catalytic layer. This design allows gas to flow through, trap CO2, and convert it simultaneously. In lab tests with pure CO2, it achieved about 40% higher efficiency than comparable electrodes. Performance shone brighter in simulated flue gas—15% CO2, 8% oxygen, and 77% nitrogen—where it produced significant formic acid, while rivals yielded minimal output.
Impressively, the system functions even at ambient air's low CO2 concentrations, paving the way for broader applications. "This work shows that carbon capture and conversion do not need to be treated as separate steps. By integrating both functions into a single electrode, we demonstrate a simpler pathway for CO2 utilization under realistic gas conditions," Choi explained.
The researchers, including Donglai Pan and Myoung Hwan Oh, suggest this could extend to other greenhouse gases like methane. Funded by the National Research Foundation of Korea, the study appears in ACS Energy Letters (DOI: 10.1021/acsenergylett.5c03504). This advance highlights a step toward practical carbon reuse in industry.
