Development of 200W Class Direct Formic Acid Fuel Cell Stack Using Bi-Modified Pt/C Catalyst By Irreversible Adsorption

Tuesday, 3 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
M. Choi, S. Yang, J. Kim, H. J. Jin (KEPCO Research Institute), and C. K. Rhee (Chungnam National University)
Formic acid has been attracting attention as an energy storage medium because of its excellent ability to store hydrogen. In addition, technologies to convert CO2, a greenhouse gas, into formic acid are being developed. It is expected that a large amount of environment-friendly formic acid from recycled CO2 will be produced in the near future. DFAFC has been actively developed in recent years because of high electro-motive force (EMF), low fuel crossover through membrane, non-flammable, and low toxic. However, the electrooxidation performance of formic acid is degraded by CO poison on platinum catalyst in DFAFC. In this study, the characteristics of DFAFC using Bi-modified Pt/C catalyst by irreversible adsorption was investigated in order to improve the performance of platinum catalysts. Bi-modified Pt/C (Bi/Pt/C) catalyst was used for the anode catalyst layer at a loading of 1.2 mg·cm-2. The cathode consisted of unsupported Pt black at a loading of 3.0 mg·cm-2. The DFAFC stack was comprised of 35 cells with 50 cm2 electrode. For single-cell with 5.06 cm2, the performance of DFAFC based on Bi/Pt/C catalyst was more than 2 times higher than that of Pt/C catalyst. The maximum and the average power output of 35-cell stack was 301 W and 200 W at 60 oC, 6 M formic acid and air, respectively. The maximum power density of the cell with the best performance among the cells in the stack was 202.4 mW·cm-2. The high performance of the DFAFC stack demonstrates that it has a great potential for the power supply of portable electronics or small transport vehicles such as electric bicycles.