Metal–organic framework for high-performance catalyst layers in proton-exchange membrane fuel cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 11; no. 38; pp. 20583 - 20591
• Main Authors: Choi, Inyoung, Lim, Jinhyuk, Reis, Roberto dos, Kim, Eunji, Lim, Soo Yeon, Dravid, Vinayak P., Kim, Heejin, Oh, Keun-Hwan, Nam, Kwan Woo
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 04.10.2023
• Subjects: Air purification; Catalysts; Cathodes; Concentration gradient; Diffusion; Durability; Electric vehicles; Fuel cells; Fuel technology; Functional materials; Hydrogen; Membranes; Metal-organic frameworks; Moisture content; Performance degradation; Power sources; Proton exchange membrane fuel cells; Protons; Relative humidity; Water content; Zirconium
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D3TA04377K

Proton (H + )-exchange membrane fuel cells (PEMFCs) are considered effective power sources for fuel cell electric vehicles because of their clean emission, air-purification capability, and excellent durability. However, the performance degradation at low relative humidity (RH) remained to be addressed. Water back-diffusion, which refers to the diffusion of water from the cathode to the membrane by a concentration gradient, could lead to a remarkable improvement in the H + conductivity of membrane/electrode assemblies (MEAs) at low RH. This effect can be achieved by introducing a functional material with a high water content into the cathode catalyst layer. Herein, we propose a Zr-based metal–organic framework (MOF; UiO-66(Zr)-(COOH) 2 ) as a water-rich additive material in the MEA and demonstrate that it increases the power performance of PEMFCs at low RH by promoting water back-diffusion. The high compositional and structural tunability of MOFs will expand the pool of materials to adjust the humidity level of PEMFCs.