Water electrolysis using fluorine-free, reinforced sulfo-phenylated polyphenylene membranes

Author(s)

Egemole, Franklin O. ; Biancolli, Ana Laura G. ; Holdcroft, Steven

• Document type: Journal article
• Source: Electrochimica Acta; v. 508, p. 8-pg., 2024-10-31.

Abstract

Fluorinated proton-exchange membranes (PEMs), such as NafionTM, which is the current state-of-the-art polymer, present environmental challenges, driving the need for more sustainable alternatives for proton-exchange membrane water electrolysis (PEMWE) systems. However, fluorine-free membranes like sulfo-phenylated polyphenylene biphenyl (sPPB-50) often suffer from mechanical instability, excessive swelling, and limited cell durability, which hinder their practical applications. This study explores reinforced fluorine-free sulfo-phenylated polyphenylene membranes (PemionTM) with thicknesses of 15 mu m (Pemion-15) and 40 mu m (Pemion-40) as a potential solution to these issues. Pemion membranes were compared with both sPPB-50 and NafionTM 112 (N112), focusing on key properties such as water uptake, dimensional swelling, proton conductivity, and durability in PEMWE applications. The results show that Pemion-reinforced membranes exhibit good performance for PEMWE allowing high current densities at lower voltages. Pemion-40 exhibited a low hydrogen gas crossover compared to sPPB-50 and N112. Under a constant current of 1 A cm- 2 , Pemion-40 exhibited a voltage loss rate of 1.46 mV h- 1 over 100 h of operation. This study highlights the importance of structural reinforcement in enhancing the stability and efficiency of fluorine-free membranes, providing a promising route for sustainable alternatives in PEMWE systems. (AU)

• FAPESP's process: 19/26955-3 - Synthesis of anion exchange membranes and ionomers for application in electrochemical conversion devices
• Grantee: Ana Laura Gonçalves Biancolli
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 21/14786-2 - Highly stable anion exchange membranes: synthesis and electrochemical applications
• Grantee: Ana Laura Gonçalves Biancolli
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 17/11937-4 - A sustainable path to methane conversion by advanced electrochemical technologies
• Grantee: Fabio Coral Fonseca
• Support Opportunities: Research Grants - Research Centers in Engineering Program